This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nordestgaard, B. G. Articles by Tybjærg-Hansen, A. Search for Related Content PubMed PubMed Citation Articles by Nordestgaard, B. G. Articles by Tybjærg-Hansen, A.

(Circulation. 1997;96:1737-1744.)
© 1997 American Heart Association, Inc.

Articles

Heterozygous Lipoprotein Lipase Deficiency

Frequency in the General Population, Effect on Plasma Lipid Levels, and Risk of Ischemic Heart Disease

Børge G. Nordestgaard, MD, DMSc; Susanne Abildgaard, MSc; Hans H. Wittrup, MD; Rolf Steffensen, MD; Gorm Jensen, MD, DMSc; ; Anne Tybjærg-Hansen, MD, DMSc

From the Department of Clinical Biochemistry, Herlev University Hospital, Herlev (B.G.N., S.A., H.H.W., A.T.-H.); the Copenhagen City Heart Study, Rigshospitalet, National University Hospital (B.G.N., G.J., A.T.-H.); and the Department of Medicine B, Division of Cardiology (R.S.) and Department of Clinical Biochemistry (A.T.-H.), Rigshospitalet, National University Hospital, Copenhagen, Denmark.

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Background Patients with mutations on both alleles of the lipoprotein lipase gene resulting in complete lipoprotein lipase deficiency exhibit the chylomicronemia syndrome with severe hypertriglyceridemia and increased risk of pancreatitis and possibly of ischemic heart disease. This study examined frequency, lipid levels, and risk of ischemic heart disease for heterozygous carriers of lipoprotein lipase mutations known to cause the chylomicronemia syndrome in the homozygous state.

Methods and Results Two mutations were screened for in 9259 individuals in a general population sample and in 948 patients with verified ischemic heart disease. The percent frequencies of heterozygous individuals with the Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions in the general population were 0.06% (95% CI, 0.04% to 0.23%) and 0% (95% CI, 0.00% to 0.12%), respectively. The Gly¹⁸⁸Glu substitution was associated with an increase in plasma triglycerides of 0.8±0.3 mmol/L (mean±SEM) and a decrease in plasma HDL cholesterol, apo A-I, and glucose levels of 0.45±0.07 mmol/L, 17±6 mg/dL, and 1.1±0.2 mmol/L, respectively. On multiple logistic regression analysis allowing for age, sex, plasma cholesterol, plasma lipoprotein (a), hypertension, diabetes mellitus, smoking, and body mass index, both plasma triglycerides and HDL cholesterol levels were independent predictors of ischemic heart disease. Finally, the Gly¹⁸⁸Glu substitution was more common among patients with verified ischemic heart disease (percent frequency of heterozygous individuals, 0.32%) than among individuals from the general population (odds ratio, 4.9; 95% CI, 1.2 to 19.6). The effects of the Gly¹⁸⁸Glu substitution were more pronounced than those of the common Asn²⁹¹Ser substitution.

Conclusions Heterozygous lipoprotein lipase deficiency due to the Gly¹⁸⁸Glu substitution appears to increase plasma triglycerides and reduce HDL levels and may thereby predispose carriers to ischemic heart disease.

Key Words: atherosclerosis • coronary disease • lipoproteins • genes

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
The enzyme LPL plays a crucial role in the catabolism of triglycerides contained in chylomicrons and large VLDLs.¹ If these particles are converted into chylomicron remnants and smaller VLDLs or IDLs, plasma triglyceride levels are decreased.

In studies of patients with severe hypertriglyceridemia, the so-called chylomicronemia syndrome, more than 40 different structural mutations in the homozygous or compound heterozygous state have been described in the LPL gene over the past few years.¹ As a result of such mutations, the enzyme is either not produced or becomes catalytically defective, and these patients typically exhibit severe chylomicronemia, hepatosplenomegaly, episodes of abdominal pain, pancreatitis, and eruptive xanthomas but in most cases not ischemic heart disease. It has recently been shown, however, that ischemic heart disease may be seen in some patients with either homozygous or compound heterozygous forms of LPL mutations.² The majority of the mutations have been located to exons 4, 5, and 6 in the LPL gene and have been described in only a single or very few probands; phylogenetically, these exons are the most conserved regions of the LPL gene and probably contain the catalytic site, a triad of Ser¹³², Asp¹⁵⁶, and His²⁴¹.¹ Two single-base mutations in exon 5, however, the Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions, respectively, have both been described in several kindreds of mainly European descendance.^{1 3 4 5 6} This opens up the possibility for a search within the general populations of European heritage for individuals with these mutations in the heterozygous state to determine the frequency of the mutations as well as the associated phenotype.

Obligate heterozygotes for LPL deficiency have decreased LPL activity and mass and, in some families, increased plasma cholesterol and/or increased plasma triglycerides.⁷ Another study suggested that obligate heterozygotes for the Gly¹⁸⁸Glu substitution in the LPL protein have only elevated plasma triglycerides rather than elevations of both plasma cholesterol and triglycerides⁸ ; in this study, however, there was evidence for another putative gene causing increased triglycerides on the maternal side. Therefore, the exact phenotype associated with LPL mutations in the heterozygous state remains unclear, particularly because only obligate heterozygotes have been studied so far and no information is available on carriers found in the general population. Furthermore, it is still unknown whether such LPL mutations in the heterozygous state predispose carriers to ischemic heart disease.

We screened for the mutations in the LPL gene causing the Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions in 9259 individuals from a general population sample, the Copenhagen City Heart Study, and in 948 patients with verified ischemic heart disease. This enabled us to determine the frequency in the general population. By comparing lipid levels as well as other clinical and biochemical characteristics of the probands with the age- and sex-matched percentiles in the total general population sample, we were also able to examine the phenotypic expression of these mutations in vivo, which gave us some insight into whether these mutations predispose heterozygous carriers to ischemic heart disease or not. Finally, we compared the effects of heterozygosity for the Gly¹⁸⁸Glu substitution with those of the common Asn²⁹¹Ser substitution in LPL.⁹

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Subjects
First, a general population sample (the Copenhagen City Heart Study) with an almost equal number of men and women stratified into age groups from 20 to 80 years was drawn from the Copenhagen Central Population Register with the aim of obtaining a sample representing the Danish general population.¹⁰ Fewer than 1% were nonwhite, and 98.8% had Danish citizenship, ie, for practical purposes were of Danish descent. The sample was collected in 1991 through 1994: of the 17 180 individuals invited, 10 049 participated, and among these, 9259 individuals gave blood.

Second, 992 consecutive patients from the greater Copenhagen area were referred for coronary angiography in the period 1991 to 1993. Among these, 948 (26% women) had ischemic heart disease with characteristic symptoms plus at least one of the following characteristics: severe stenosis on coronary angiography (n=767) (ie, >70% stenosis of at least one coronary artery or >50% stenosis of the left main coronary artery), a previous myocardial infarction, or a positive exercise ECG. Fewer than 1% were nonwhite, and >98% had Danish citizenship, ie, for practical purposes were of Danish descent.

The present studies were approved by Danish ethical committees: No. 100.2039/91 Copenhagen and Frederiksberg committee and No. KA 93125 Copenhagen County committee.

DNA Isolation
From each individual, total genomic DNA was isolated from a whole-blood sample as described.¹¹ For the purpose of rapid screening, whole blood was pooled from 10 or 20 individuals (from heart patients and the general population, respectively): 200 µL of whole blood from each individual was pooled, the blood was mixed thoroughly, and DNA was isolated with a commercially available kit (QIAamp Blood Kit, QIAGEN GmbH).

Screening for the Gly¹⁸⁸Glu Substitution
This substitution is caused by a GA missense mutation in codon 188 (GGGGAG) of the LPL gene.³ Initially, DNA from the 948 patients with ischemic heart disease was first screened individually by AvaII restriction enzyme digestion of PCR-amplified DNA; presence of the mutation causes loss of an AvaII site. Part of intron 4 and most of exon 5 of the LPL gene were amplified in a PCR assay with an automated thermocycler (Omnigene Thermal Cycler, Hybaid Ltd). The 100-µL PCR assay contained 1 µmol/L sense (5'-GAGCAGTGACATGCGAATGT-3') and antisense (5'-CTCCAAGTCCTCTCTCTGCA-3') primers (DNA Technology Aps); 190 µmol/L each of d'ATP, d'TTP, d'GTP, and d'CTP; 1.5 mmol/L MgCl₂; 1 U Taq DNA polymerase; 1x PCR amplification buffer (all from Life Technologies Inc); and 5 µL DNA sample (0.1 to 0.2 µg DNA). The thermal cycling procedure was as follows: 1 cycle of 5 minutes at 94°C, 30 seconds at 50°C, and 60 seconds at 72°C; 30 cycles of 30 seconds at 94°C, 30 seconds at 50°C, and 60 seconds at 72°C; and finally 1 cycle of 30 seconds at 94°C, 30 seconds at 50°C, and 5 minutes at 72°C. The PCR product was digested overnight with 1 U AvaII (Biolabs) at 37°C and was diagnosed in a 4% agarose gel as undigested (305 bp), two normal alleles (131, 88, and 86 bp), or one normal and one mutated allele (219, 131, 88, and 86 bp).

Subsequently, whole blood from 1 of the 3 probands found with the Gly¹⁸⁸Glu substitution was used to construct a "mutation-positive" pool of 20 individuals, as described above. This DNA pool served as a positive control in an allele-specific PCR assay. The design of this assay was similar to that described above, except that the antisense primer (5'-CCAAGTCCTCTCTCTGCAATCAGG-3') had a concentration of 0.05 µmol/L as opposed to 1 µmol/L for the sense (5'-GGCCTCGATCCAGCTGGACC-3') and mutation-specific antisense (mutation in italics and underlined) (5'-AATGCTTCGACCAGGGCACT 3') primers. In the mutation-specific primer, an extra base change was introduced 3 bases downstream from the mutation (underlined only), causing a C-to-C mismatch. These modifications ensured that the allele-specific primer, under the conditions used, would anneal only when the mutation was present and that in such a case, amplification of the mutation-specific PCR product (123 bp) would be favored compared with the normal PCR product (233 bp). The thermal cycling was identical to that described above except for an annealing temperature of 60°C. The DNA products were diagnosed in a 3% agarose gel.

The allele-specific PCR assay detected three and six DNA pools to be positive for the mutation among patients with ischemic heart disease and among individuals in the general population sample, respectively. DNA from each of the 10 or 20 individuals in each of these DNA pools were then tested individually with the allele-specific PCR assay; among heart patients, the same 3 individuals as initially identified with the AvaII restriction enzyme assay were found to be mutation positive. The AvaII restriction enzyme assay was used for final confirmation of the diagnosis.

Screening for the Ile¹⁹⁴Thr Substitution
This substitution is caused by a TC missense mutation in codon 194 (ATTACT) of the LPL gene.⁵ DNA from a heterozygous proband (kindly provided by H.E. Henderson, University of Cape Town, South Africa) was used to construct a "mutation-positive" pool of 20 individuals. This pool served as the positive control in the assay screening pooled DNA samples. The composition and thermal cycling of the allele-specific PCR assay were similar to that described above, except for a different mutation-specific antisense primer (mutation in italics and underlined) (5'-CCAACTGGTTTCTGGATTACAG-3') causing an additional A-to-G mismatch 3 bases downstream from the mutation (underlined only); this yielded a 233-bp normal PCR product and a 143-bp mutation-specific PCR product.

Other Analyses
Colorimetric and turbidimetric assays were used to measure nonfasting (general population) or fasting (heart patients) plasma levels of total cholesterol, HDL cholesterol, triglycerides, glucose, apo B, apo A-I (CHOD-PAP, precipitation of apo B–containing lipoproteins followed by CHOD-PAP, GPO-PAP, hexokinase method, sheep anti-human apo B, and sheep anti-human apo A-I, respectively; all from Boehringer Mannheim), and lipoprotein (a) [rabbit anti-human lipoprotein (a), DAKO A/S]. Body mass index and blood pressure were determined as described previously,¹⁰ as was apo E genotyping.¹² Waist-to-hip ratio was the body circumference measured midway between the lower rib margin and the iliac crest divided by the maximum circumference over the buttocks.

Analysis of Results
To examine the effect of mutations on phenotype, all values for each proband were converted to their respective percentiles in the total general population sample¹³ ; percentiles for the proband's own sex group and 10-year age group were used at increments of 1%. These percentiles were converted to standardized normal deviations (z scores), and for a given parameter (eg, HDL cholesterol), z-score distribution was examined by comparing the mean z score with the standard gaussian distribution.¹⁴ The variances of the z scores were tested for differences compared with the general population variance of 1 by ² distribution.¹⁴ In addition, to compare effects of the Gly¹⁸⁸Glu substitution with those of the Asn²⁹¹Ser substitution, plasma triglycerides, apo A-I, and HDL cholesterol levels were adjusted by ANCOVA (see "Results").

Multivariate logistic regression analysis with forced entry¹⁵ was performed to investigate whether plasma triglycerides, HDL cholesterol, and apo A-I were independent predictors of ischemic heart disease when conventional cardiovascular risk factors were allowed for; plasma glucose was not available for patients with ischemic heart disease and therefore could not be tested. To approach linearity in the logit, square-root, logarithmic, or inverse transformations were used for some but not all covariates. Because individuals >70 years old are unlikely to be referred to coronary angiography in Denmark, only individuals <70 years old were included in the logistic regression analysis. The ability to predict ischemic heart disease was expressed as an odds ratio (e^ß) with 95% CIs (e^ß±1.96xSEM), for an increase of 1 SD in the variable. The likelihood ratio test between models including and excluding the parameter of interest was the test of significance.

Student's t test and calculation of odds ratios were also performed¹⁵ ; Fisher's exact test was used as a test of independence. Statistical tests were two-tailed, with the level of significance chosen as P<.05.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Frequency in the General Population
The Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions in the LPL protein were identified in 6 and 0 individuals, respectively, from among 9259 individuals in a general population sample. Accordingly, the 95% CIs for the percent frequencies of heterozygous individuals with these two mutations in the Danish population are 0.04% to 0.23% and 0.00% to 0.12%, respectively. Among the 948 patients with ischemic heart disease, 3 (0.32%) and 0 (0%) carried the Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions, respectively.

Gly¹⁸⁸Glu Substitution and Phenotypic Characteristics
Characteristics in terms of absolute values for the 9 unrelated probands heterozygous for the Gly¹⁸⁸Glu substitution in the LPL protein are shown in Table 1. For comparison, mean values for the total general population sample and for all patients with ischemic heart diseases are likewise shown in Table 1; the predictors of ischemic heart disease are consistent with findings from numerous previous studies. At the time of investigation, none of the probands were being treated with lipid-lowering, antidiabetic, or antihypertensive drugs, except proband 6, who received the calcium antagonist verapamil, and proband 8, who received bezafibrate at a low dose when plasma apo B, apo A-I, and lipoprotein (a) were measured. The 24-year-old woman (proband 1) took oral contraceptives.

View this table: [in this window] [in a new window]   Table 1. Characteristics of Unrelated Probands Heterozygous for the Gly188Glu Substitution

Because all continuous characteristics were measured simultaneously in all other participants of the Copenhagen City Heart Study, it was possible to assign each proband to a percentile in the relevant sex group and 10-year age group (Figs 1 and 2). When all 9 probands were examined, plasma triglycerides were significantly increased and plasma HDL cholesterol, apo A-I, and glucose significantly reduced; however, patients with ischemic heart disease were fasting at the time of examination and individuals in the general population cohort were not. The same conclusions were nevertheless drawn for plasma triglycerides, HDL cholesterol, and plasma glucose when the 6 probands identified in the general population were examined separately (P=.02, P=.01, and P=.05, respectively), whereas plasma apo A-I was then no longer significantly reduced (P=.14). There was no evidence that the variances of the phenotypic characteristics shown in Figs 1 and 2 were different from the equivalent variances in the general population (all comparisons, P>.05), except that plasma triglycerides had a smaller variance among probands than in the general population sample (P<.05).

View larger version (22K): [in this window] [in a new window]   Figure 1. Plasma lipid and lipoproteins for heterozygous Gly188Glu probands relative to age- and sex-matched individuals in the general population.

View larger version (18K): [in this window] [in a new window]   Figure 2. Body mass index, waist-to-hip ratio, plasma glucose, and blood pressure for heterozygous Gly188Glu probands relative to age- and sex-matched individuals in the general population.

The effect of the Gly¹⁸⁸Glu substitution was an increase in plasma triglycerides of 0.8±0.3 mmol/L (mean±SEM) and a decrease in plasma HDL cholesterol, apo A-I, and glucose levels of 0.45±0.07 mmol/L, 17±6 mg/dL, and 1.1±0.2 mmol/L, respectively; when the 6 probands from the general population sample were considered alone, the increase in plasma triglycerides and decrease in plasma HDL cholesterol, apo A-I, and glucose were 0.9±0.4 mmol/L, 0.41±0.10 mmol/L, 16±7 mg/dL, and 0.9±0.2 mmol/L, respectively. This effect of the Gly¹⁸⁸Glu substitution was calculated as the absolute difference between the proband's own value and the mean value for the matched sex group and 10-year age group, thus allowing for the effect of age and sex.

Triglycerides, HDL Cholesterol, and Risk of Ischemic Heart Disease
On univariate analysis, plasma triglyceride, HDL cholesterol, and apo A-I levels all were predictors of ischemic heart disease (Table 1). Furthermore, on multiple logistic regression analyses allowing for age, sex, plasma cholesterol, plasma lipoprotein (a), hypertension, diabetes mellitus, smoking, and body mass index, both plasma triglycerides and HDL cholesterol levels were still predictors of ischemic heart disease (Table 2).

View this table: [in this window] [in a new window]   Table 2. Plasma Triglycerides, HDL Cholesterol, and Apo A-I as Predictors of Ischemic Heart Disease by Multiple Logistic Regression

Gly¹⁸⁸Glu Substitution and Risk of Ischemic Heart Disease
The Gly¹⁸⁸Glu substitution in the LPL protein was found more frequently among patients with verified ischemic heart disease than among individuals in the general population (odds ratio, 4.9; 95% CI, 1.2 to 19.6) (Table 3). When the comparison was limited to age 40 to 75 years or to men only, comprising 94% and 74%, respectively, of patients with verified ischemic heart disease and 72% and 45% of individuals in the general population sample, the odds ratios were 7.5 (95% CI, 1.5 to 37.0) and 4.4 (95% CI, 1.0 to 19.9), respectively. This mutation was also more common among patients with severe stenosis on coronary angiography than in the general population sample (odds ratio, 6.1; 95% CI, 1.5 to 24.3).

View this table: [in this window] [in a new window]   Table 3. Odds Ratios of Ischemic Heart Disease for Probands Heterozygous for the Gly188Glu Substitution

The 3 probands identified among patients with verified ischemic heart disease developed angina pectoris between the ages of 46 and 58 years (Table 1). Among probands identified in the general population sample, only 1 developed ischemic heart disease, but among the remaining 5 individuals, 3 were <50 years old, and the 72-year-old man was thin, with a body mass index of only 19.

Comparison of the Gly¹⁸⁸Glu and Asn²⁹¹Ser Substitutions
Heterozygous carriers of the Gly¹⁸⁸Glu substitution were rare, whereas heterozygous carriers of the Asn²⁹¹Ser substitution were common, in the Danish general population (Fig 3); no individual carried both substitutions. The observed effects on plasma triglycerides, apo A-I, and HDL cholesterol levels, however, were more pronounced in individuals heterozygous for the Gly¹⁸⁸Glu substitution than in those heterozygous for the Asn²⁹¹Ser substitution. Furthermore, the odds ratio for ischemic heart disease was larger for Gly¹⁸⁸Glu heterozygotes than for Asn²⁹¹Ser heterozygotes.

View larger version (35K): [in this window] [in a new window]   Figure 3. Changes in adjusted levels of plasma triglycerides, apo A-I, and HDL cholesterol; frequency in the general population; and odds ratio for ischemic heart disease for individuals heterozygous for the Gly188Glu and Asn291Ser substitutions in LPL. Plasma values were adjusted by ANCOVA for age, body mass index, diabetes mellitus, antihypertensive and diuretic medication, alcohol consumption (beer, wine, and liquor), smoking habits, physical activity (at work and leisure), among women also for menopausal status and hormonal replacement therapy, and also in analysis of Gly188Glu substitution for sex. P values for plasma levels represent Student's t test between carriers and noncarriers within total general population sample. P values for odds ratios represent Fisher's exact test or 2. Numbers of individuals represent numbers of heterozygotes in the general population sample. Values for Asn291Ser substitution are from a previous study.9

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
A new observation in the present study is the observed percent frequency of heterozygous carriers of the Gly¹⁸⁸Glu and Ile¹⁹⁴Thr substitutions in LPL in the Danish general population of 0.06% and 0%, respectively; <1% of the individuals screened were nonwhite, and >98% had Danish citizenship, ie, for practical purposes were of Danish descent.

The importance of a given mutation for phenotypic expression is often evaluated by examining characteristics of index patients and their relatives. Because index patients as a rule are identified among patients with a characteristic phenotype (eg, hyperlipidemia or ischemic heart disease) and not among individuals in the general population, this approach would tend to overestimate the effect of the mutation, even among obligate heterozygotes; other genes or environmental factors of importance for the phenotype may cluster in such families. Alternatively, in vitro expression systems have been used to measure the effect of a given mutation on the expression of the protein coded for, but some of these effects could be modulated in vivo. Transgenic animals have also been used to study effects of mutations relative to the wild-type protein, with the limitation that these effects may not represent those in humans. Our present approach of identifying unrelated individuals with the same mutation within the general population and comparing the characteristics of the individuals identified with those for age- and sex-matched individuals in the general population may give a better estimate of the "true" phenotype of a given mutation in humans.

The present finding of an increase in nonfasting plasma triglycerides among unrelated heterozygous carriers of the Gly¹⁸⁸Glu substitution is in accordance with previous findings in obligate heterozygous carriers of the same or other mutations in the LPL gene in the postprandial or fasting state.^{1 4 7 8 16 17 18 19 20 21 22 23 24} Also in support of this finding, the Gly¹⁸⁸Glu substitution was found in 6 of 95 unrelated Canadians with type IV hyperlipidemia, ie, with elevated levels of triglycerides due to VLDL elevations, but not among normotriglyceridemic subjects.²⁵ The HDL cholesterol–reducing effect of heterozygous LPL deficiency found in the present study is also in agreement with previous observations in obligate heterozygous individuals,^{7 8 18 23 24} as is the present finding of reduced apo A-I levels among carriers.²³ Obligate heterozygous carriers have on one occasion been shown to have elevated plasma apo B levels,⁷ a finding that was not confirmed in the present study, although a similar trend was observed (Fig 1; two-tailed P=.11, one-tailed P=.054). The previously reported elevation of systolic blood pressure among obligate heterozygous carriers²⁴ was not confirmed in the present study (Fig 2).

Because the Gly¹⁸⁸Glu substitution in LPL appears to cause a moderate elevation in plasma triglycerides and a reduction in HDL levels and because these two cardiovascular risk factors have been found to be independent predictors of ischemic heart disease in the present and former studies,^{26 27} the data seem to suggest that this substitution represents a susceptibility mutation for ischemic heart disease. In support of this, we observed a higher frequency of the Gly¹⁸⁸Glu substitution among patients with ischemic heart disease than among individuals in the general population; there is, however, a 4% probability that the observed distribution is a chance finding. The present data also suggest that this mutation represents only a relatively weak susceptibility mutation, because the 4 carriers with ischemic heart disease had their initial disease manifestations in the age range of 46 to 67 years and because 2 male probands 59 and 72 years old had not yet experienced manifestations of ischemic heart disease.

An unexpected new observation is the plasma glucose–lowering effect of heterozygous LPL deficiency, which could easily represent a chance observation. Former studies in Gly¹⁸⁸Glu heterozygotes found no plasma glucose–reducing effect,^{8 16} and our observation therefore needs to be confirmed by other groups.

A number of potential limitations of the present study should be considered: (1) Were there any false-positives? This possibility can be excluded because each proband was diagnosed by two different methods. (2) Were there any false-negatives? To examine this possibility, we tested all 948 patients with verified ischemic heart disease by both detection methods and found complete concordance. (3) Individuals in the general population sample had blood samples drawn in the nonfasting state, whereas the patients' blood was drawn in the fasting state. This could potentially be a problem for values of plasma glucose and triglycerides; however, plasma glucose was reduced and plasma triglycerides were increased when all probands were examined as well as when only the 6 probands identified within the general population cohort were considered. As an estimate of the variation in plasma lipids due to the nonfasting state, the Copenhagen City Heart Study has previously determined average levels of triglycerides and cholesterol as a function of the period after the last meal before blood sampling: 1 to 30 minutes (n=766), 30 minutes to 1 hour (n=2630), 1 to 3 hours (n=8004), or >3 hours (n=2468); average triglyceride levels for these four categories were (mean±SEM) 1.80±0.05, 1.82±0.02, 1.77±0.01, and 1.66±0.02 mmol/L, respec- tively. The equivalent values for plasma cholesterol were 5.95±0.04, 6.00±0.02, 6.14±0.01, and 6.21±0.03 mmol/L, respectively. (4) Finally, the samples examined (general population sample and patients with verified ischemic heart disease) may not truly represent the general population and patients with ischemic heart disease because of bias due to nonresponders or selection bias.²⁸ If the Gly¹⁸⁸Glu substitution in fact is a susceptibility mutation for ischemic heart disease, a disease that could increase the likelihood that invited individuals did not respond to the Copenhagen City Heart Study, this substitution could be underrepresented among responders in the Copenhagen City Heart Study, and thereby the observed odds ratio for ischemic heart disease for heterozygous carriers could be overestimated.

Nevertheless, mechanistically it is plausible that heterozygous LPL deficiency could lead to an increased risk of ischemic heart disease. Individuals heterozygous for the Gly¹⁸⁸Glu substitution have an 50% reduction in LPL activity,^{8 16} which may explain the observed increase in plasma triglycerides and reduction in HDL cholesterol. LPL normally removes triglycerides from chylomicrons and VLDLs, and as a byproduct, HDL particles are formed from the generated excess surface material of these large, triglyceride-rich lipoproteins.¹ In observational epidemiological studies, both elevated plasma triglycerides and decreased plasma HDL cholesterol levels have been associated with an increased risk of ischemic heart disease,^{26 27} exactly as was also found in the present study. A modest increase in plasma triglycerides, such as that associated with heterozygous LPL deficiency, implies that more cholesterol in plasma is carried in IDL, small VLDL, or chylomicron remnant particles rather than in LDL particles only. These triglyceride-rich lipoproteins may be retained selectively in the arterial intima,²⁹ leading to increased development of atherosclerosis and eventually to ischemic heart disease; triglyceride-rich lipoprotein particles have been shown in vitro to be taken up directly by macrophages to produce foam cells,^{30 31} a key cell type in the atherosclerotic plaque. It is worth noting that only the relatively smaller chylomicron remnants and VLDL and IDL particles may be involved, because large chylomicrons and VLDLs with a diameter >75 nm (like those present in the plasma of patients with complete LPL deficiency¹ ) are excluded from the intima.³² A decrease in plasma HDL cholesterol levels may be an indicator of reduced ability to remove cholesterol from the arterial intima, potentially leading to more atherosclerosis and ischemic heart disease.³³ Finally, elevated plasma triglycerides have been shown to be associated with a subclass of small, dense LDL particles that by themselves may promote atherogenesis.²⁶ The present data suggest that neither diabetes mellitus, hypertension, obesity, elevated plasma lipoprotein (a) levels, nor the apo E4 genotype is necessary for Gly¹⁸⁸Glu carriers to develop ischemic heart disease.

The potential total impact of heterozygous LPL deficiency on risk of ischemic heart disease in countries with affluent lifestyles can currently only be guessed. Assuming that all LPL mutations known to cause the chylomicronemia syndrome in the homozygous or compound heterozygous state (frequency, 1 per million¹ ) predispose heterozygous carriers to ischemic heart disease, a total of 2000 per million individuals may be at increased risk of ischemic heart disease due to such LPL mutations in the heterozygous state. However, two common LPL mutations causing the Asp⁹Asn and Asn²⁹¹Ser substitutions may also be important. The presence of the Asn²⁹¹Ser substitution in the heterozygous state is associated with a decrease in postheparin plasma LPL activity of 30%,^{34 35} an increase in plasma triglycerides,^{9 25 35 36 37 38 39} and a decrease in HDL levels,^{9 34 35 36 38 39} as well as with an increased odds ratio for ischemic heart disease in women⁹ ; these effects were less pronounced for the Asn²⁹¹Ser substitution than for the Gly¹⁸⁸Glu substitution (Fig 3). The Asp⁹Asn substitution is associated with elevated plasma triglycerides,^{40 41} reduced HDL levels,⁴² and increased progression of coronary atherosclerosis.⁴² Finally, mutations in the LPL promoter⁴³ may also affect plasma lipid levels and risk of ischemic heart disease, although evidence for this is still lacking.

	Selected Abbreviations and Acronyms

 

apo = apolipoprotein LPL = lipoprotein lipase PCR = polymerase chain reaction

	Acknowledgments

 
This study was supported by the Danish Heart Foundation and the Danish foundation Lægeforeningens Forskningsfond. Thanks to Jørgen Hilden for in-depth statistical advice.

	Footnotes

 
Reprint requests to Børge G. Nordestgaard, MD, DMSc (Dr med), Department of Clinical Biochemistry, 54 M1, Herlev University Hospital, DK-2730 Herlev, Denmark.

Drs Abildgaard and Wittrup contributed equally to this article.

Received February 12, 1997; revision received April 8, 1997; accepted April 18, 1997.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Brunzell J. Familial lipoprotein lipase deficiency and other causes of the chylomicronemia syndrome. In: Scriver C, Beaudet A, Sly W, Valle D, eds. The Metabolic and Molecular Bases of Inherited Disease. 7th ed. New York, NY: McGraw-Hill Inc; 1995:1913-1932.

2. Benlian P, De Gennes JL, Foubert L, Zhang H, Gagné SE, Hayden M. Premature atherosclerosis in patients with familial chylomicronemia caused by mutations in the lipoprotein lipase gene. N Engl J Med. 1996;335:848-854.[Abstract/Free Full Text]

3. Monsalve MV, Henderson H, Roederer G, Julien P, Deeb S, Kastelein JJP, Peritz L, Devlin R, Bruin T, Murthy MRV, Gagne C, Davignon J, Lupien PJ, Brunzell JD, Hayden MR. A missense mutation at codon 188 of the human lipoprotein lipase gene is a frequent cause of lipoprotein lipase deficiency in persons of different ancestries. J Clin Invest. 1990;86:728-734.

4. Emi M, Wilson DE, Iverius P-H, Wu L, Hata A, Hegele R, Williams RR, Lalouel J-M. Missense mutation (GlyGlu¹⁸⁸) of human lipoprotein lipase imparting functional deficiency. J Biol Chem. 1990;265:5910-5916.[Abstract/Free Full Text]

5. Henderson HE, Ma Y, Hassan MF, Monsalve MV, Marais AD, Winkler F, Gubernator K, Peterson J, Brunzell JD, Hayden MR. Amino acid substitution (Ile¹⁹⁴Thr) in exon 5 of the lipoprotein lipase gene causes lipoprotein lipase deficiency in three unrelated probands: support for a multicentric origin. J Clin Invest. 1991;87:2005-2011.

6. Dichek HL, Fojo SS, Beg OU, Skarlatos SI, Brunzell JD, Cutler GB Jr, Brewer HB Jr. Identification of two separate allelic mutations in the lipoprotein lipase gene of a patient with the familial hyperchylomicronemia syndrome. J Biol Chem. 1991;266:473-477.[Abstract/Free Full Text]

7. Babirak SP, Iverius P-H, Fujimoto WY, Brunzell JD. Detection and characterization of the heterozygote state for lipoprotein lipase deficiency. Arteriosclerosis. 1989;9:326-334.[Abstract/Free Full Text]

8. Wilson DE, Emi M, Iverius P-H, Hata A, Wu LL, Hillas E, Williams RR, Lalouel J-M. Phenotypic expression of heterozygous lipoprotein lipase deficiency in the extended pedigree of a proband homozygous for a missense mutation. J Clin Invest. 1990;86:735-750.

9. Wittrup HH, Tybjaerg-Hansen A, Abildgaard S, Steffensen R, Schnohr P, Nordestgaard BG. A common substitution (Asn291Ser) in lipoprotein lipase is associated with increased risk of ischemic heart disease. J Clin Invest. 1997;99:1606-1613.[Medline] [Order article via Infotrieve]

10. Appleyard M, Hansen AT, Schnohr P, Jensen G, Nyboe J. The Copenhagen City Heart Study, Østerbroundersøgelsen: a book of tables with data from the first examination (1976-78) and a five year follow-up (1981-83). Scand J Soc Med. 1989;170(suppl 41):1-160.

11. Talmud P, Tybjaerg-Hansen A, Bhatnagar D, Mbewu A, Miller JP, Durrington P, Humphries S. Rapid screening for specific mutations in patients with a clinical diagnosis of familial hypercholesterolaemia. Atherosclerosis. 1991;89:137-141.[Medline] [Order article via Infotrieve]

12. Hixson JE, Vernier DT. Restriction isotyping of human apolipoprotein E by gene amplification and cleavage with HhaI. J Lipid Res. 1990;31:545-548.[Abstract]

13. Tybjaerg-Hansen A, Humphries SE. Familial defective apolipoprotein B-100: a single mutation that causes hypercholesterolemia and premature coronary artery disease. Atherosclerosis. 1992;96:91-107.[Medline] [Order article via Infotrieve]

14. Armitage P, Berry G. Statistical computation. In: Armitage P, Berry G, eds. Statistical Methods in Medical Research. Oxford, UK: Blackwell Scientific Publications; 1987:506-509.

15. Norusis MJ. SPSS for Windows. Base System User's Guide, Release 6.0. Chicago, Ill: SPSS Inc; 1993.

16. Miesenbock G, Holzl B, Föger B, Brandstätter E, Paulweber B, Sandhofer F, Patsch JR. Heterozygous lipoprotein lipase deficiency due to a missense mutation as the cause of impaired triglyceride tolerance with multiple lipoprotein abnormalities. J Clin Invest. 1993;91:448-455.

17. Gotoda T, Yamada N, Kawamura M, Kozaki K, Mori N, Ishibashi S, Shimano H, Takaku F, Yazaki Y, Furuichi Y, Murase T. Heterogeneous mutations in the human lipoprotein lipase gene in patients with familial lipoprotein lipase deficiency. J Clin Invest. 1991;88:1856-1864.

18. Bruin T, Tuzgol S, van Diermen DE, Hoogerbrugge-van der Linden N, Brunzell JD, Hayden MR, Kastelein JJP. Recurrent pancreatitis and chylomicronemia in an extended Dutch kindred is caused by a Gly154Ser substitution in lipoprotein lipase. J Lipid Res. 1993;34:2109-2119.[Abstract]

19. Hölzl B, Huber R, Paulweber B, Patsch JR, Sandhofer F. Lipoprotein lipase deficiency due to a 3' splice site mutation in intron 6 of the lipoprotein lipase gene. J Lipid Res. 1994;35:2161-2169.[Abstract]

20. Ishimura-Oka K, Semenkovich CF, Faustinella F, Goldberg IJ, Shachter N, Smith LC, Coleman T, Hide WA, Brown WV, Oka K, Chan L. A missense (Asp250Asn) mutation in the lipoprotein lipase gene in two unrelated families with familial lipoprotein lipase deficiency. J Lipid Res. 1992;33:745-754.[Abstract]

21. Sprecher DL, Kobayashi J, Rymaszewski M, Goldberg IJ, Harris BV, Bellet PS, Ameis D, Yunker RL, Black DM, Stein EA, Schotz MC, Wiginton DA. Trp64nonsense mutation in the lipoprotein lipase gene. J Lipid Res. 1992;33:859-866.[Abstract]

22. Wilson DE, Hata A, Kwong LK, Lingam A, Shuhua J, Ridinger DN, Yeager C, Kaltenborn KC, Iverius P-H, Lalouel J-M. Mutations in exon 3 of the lipoprotein lipase gene segregating in a family with hypertriglyceridemia, pancreatitis, and non-insulin-dependent diabetes. J Clin Invest. 1993;92:203-211.

23. Bijvoet S, Gagné SE, Moorjani S, Gagné C, Henderson HE, Fruchart J-C, Dallongeville J, Alaupovic P, Prins M, Kastelein JJP, Hayden MR. Alterations in plasma lipoproteins and apolipoproteins before the age of 40 in heterozygotes for lipoprotein lipase deficiency. J Lipid Res. 1996;37:640-650.[Abstract]

24. Sprecher DL, Harris BV, Stein EA, Bellet PS, Keilson LM, Simbartl LA. Higher triglycerides, lower high-density lipoprotein cholesterol, and higher systolic blood pressure in lipoprotein lipase-deficient heterozygotes: a preliminary report. Circulation. 1996;94:3239-3245.[Abstract/Free Full Text]

25. Minnich A, Kessling A, Roy M, Giry C, DeLangavant G, Lavigne J, Lussier-Cacan S, Davignon J. Prevalence of alleles encoding defective lipoprotein lipase in hypertriglyceridemic patients of French Canadian descent. J Lipid Res. 1995;36:117-124.[Abstract]

26. Austin MA. Plasma triglyceride and coronary heart disease. Arterioscler Thromb. 1991;11:2-14.[Abstract/Free Full Text]

27. Gordon DJ, Probstfield JL, Garrison RJ, Neaton JD, Castelli WP, Knoke JD, Jacobs DR Jr, Bangdiwala S, Tyroler HA. High-density lipoprotein cholesterol and cardiovascular disease: four prospective American studies. Circulation. 1989;79:8-15.[Abstract/Free Full Text]

28. Khoury MJ, Beaty TH, Cohen BH. Fundamental epidemiologic concepts and approaches. In: Khoury MJ, Beaty TH, Cohen BH, eds. Fundamentals of Genetic Epidemiology. New York, NY: Oxford University Press Inc; 1993:55-81.

29. Nordestgaard BG, Wootton R, Lewis B. Selective retention of VLDL, IDL, and LDL in the arterial intima of genetically hyperlipidemic rabbits in vivo: molecular size as a determinant of fractional loss from the intima-inner media. Arterioscler Thromb Vasc Biol. 1995;15:534-542.[Abstract/Free Full Text]

30. Gianturco SH, Bradley WA, Gotto AM Jr, Morrisett JD, Peavy DL. Hypertriglyceridemic very low density lipoproteins induce triglyceride synthesis and accumulation in mouse peritoneal macrophages. J Clin Invest. 1982;70:168-178.

31. Van Lenten BJ, Fogelman AM, Jackson RL, Shapiro S, Haberland ME, Edwards PA. Receptor-mediated uptake of remnant lipoproteins by cholesterol-loaded human monocyte-macrophages. J Biol Chem. 1985;260:8783-8788.[Abstract/Free Full Text]

32. Nordestgaard BG, Zilversmit DB. Large lipoproteins are excluded from the arterial wall in diabetic cholesterol-fed rabbits. J Lipid Res. 1988;29:1491-1500.[Abstract]

33. Fielding CJ, Fielding PE. Molecular physiology of reverse cholesterol transport. J Lipid Res. 1995;36:211-228.[Abstract]

34. Reymer PWA, Gagné E, Groenemeyer BE, Zhang H, Forsyth I, Jansen H, Seidell JC, Kromhout D, Lie KE, Kastelein J, Hayden MR. A lipoprotein lipase mutation (Asn291Ser) is associated with reduced HDL cholesterol levels in premature atherosclerosis. Nat Genet. 1995;10:28-34.[Medline] [Order article via Infotrieve]

35. Syvänne M, Antikainen M, Ehnholm S, Tenkanen H, Lahdenperä S, Ehnholm C, Taskinen M-R. Heterozygosity for Asn²⁹¹Ser mutation in the lipoprotein lipase gene in two Finnish pedigrees: effect of hyperinsulinemia on the expression of hypertriglyceridemia. J Lipid Res. 1996;37:727-738.[Abstract]

36. Ma Y, Ooi TC, Liu M-S, Zhang H, McPherson R, Edwards AL, Forsythe IJ, Frohlich J, Brunzell JD, Hayden MR. High frequency of mutations in the human lipoprotein lipase gene in pregnancy-induced chylomicronemia: possible association with apolipoprotein E2 isoform. J Lipid Res. 1994;35:1066-1075.[Abstract]

37. Fisher RM, Mailly F, Peacock RE, Hamsten A, Seed M, Yudkin JS, Beisiegel U, Feussner G, Miller G, Humphries SE, Talmud PJ. Interaction of the lipoprotein lipase asparagine 291serine mutation with body mass index determines elevated plasma triacylglycerol concentrations: a study in hyperlipidemic subjects, myocardial infarction survivors, and healthy adults. J Lipid Res. 1995;36:2104-2112.[Abstract]

38. Reymer PW, Groenemeyer BE, Gagné E, Miao L, Appelman EEG, Seidel JC, Kromhout D, Bijvoet SM, van de Oever K, Bruin T, Hayden MR, Kastelein JJP. A frequently occurring mutation in the lipoprotein lipase gene (Asn291Ser) contributes to the expression of familial combined hyperlipidemia. Hum Mol Genet. 1995;4:1543-1549.[Abstract/Free Full Text]

39. Hoffer MJV, Bredie SJH, Boomsma DI, Reymer PWA, Kastelein JJP, de Knijff P, Demacker PNM, Stalenhoef AFH, Havekes LM, Frants RR. The lipoprotein lipase (Asn291Ser) mutation is associated with elevated lipid levels in families with familial combined hyperlipidemia. Atherosclerosis. 1996;119:159-167.[Medline] [Order article via Infotrieve]

40. Mailly F, Tugrul Y, Reymer PWA, Bruin T, Seed M, Groenemeyer BF, Asplund-Carlson A, Vallance D, Winder AF, Miller GJ, Kastelein JJP, Hamsten A, Olivecrona G, Humphries SE, Talmud PJ. A common variant in the gene for lipoprotein lipase (Asp9Asn). Functional implications and prevalence in normal and hyperlipidemic subjects. Arterioscler Thromb Vasc Biol. 1995;15:468-478.[Abstract/Free Full Text]

41. Mailly F, Fisher RM, Nicaud V, Luong L-A, Evans AE, Marques-Vidal P, Luc G, Arveiler D, Bard JM, Poirier O, Talmud PJ, Humphries SE. Association between the LPL-D9N mutation in the lipoprotein lipase gene and plasma lipid traits in myocardial infarction survivors from the ECTIM study. Atherosclerosis. 1996;122:21-28.[Medline] [Order article via Infotrieve]

42. Jukema JW, van Boven AJ, Groenemeijer B, Zwinderman AH, Reiber JHC, Bruschke AVG, Henneman JA, Molhoek GP, Bruin T, Jansen H, Gagné E, Hayden MR, Kastelein JJP, on behalf of the REGRESS Study Group. The Asp9Asn mutation in the lipoprotein lipase gene is associated with increased progression of coronary atherosclerosis. Circulation. 1996;94:1913-1918.[Abstract/Free Full Text]

43. Yang WS, Nevin DN, Peng R, Brunzell JD, Deeb SS. A mutation in the promoter of the lipoprotein lipase (LPL) gene in a patient with familial combined hyperlipidemia and low LPL activity. Proc Natl Acad Sci U S A. 1995;92:4462-4466.[Abstract/Free Full Text]

This article has been cited by other articles:

				L. Shan, X.-C. Yu, Z. Liu, Y. Hu, L. T. Sturgis, M. L. Miranda, and Q. Liu The Angiopoietin-like Proteins ANGPTL3 and ANGPTL4 Inhibit Lipoprotein Lipase Activity through Distinct Mechanisms J. Biol. Chem., January 16, 2009; 284(3): 1419 - 1424. [Abstract] [Full Text] [PDF]

				R. Frikke-Schmidt, B. G. Nordestgaard, M. C. A. Stene, A. A. Sethi, A. T. Remaley, P. Schnohr, P. Grande, and A. Tybjaerg-Hansen Association of Loss-of-Function Mutations in the ABCA1 Gene With High-Density Lipoprotein Cholesterol Levels and Risk of Ischemic Heart Disease JAMA, June 4, 2008; 299(21): 2524 - 2532. [Abstract] [Full Text] [PDF]

				A J Hooper, G M Crawford, J M Brisbane, K Robertson, G F Watts, F M van Bockxmeer, and J R Burnett Familial lipoprotein lipase deficiency caused by known (G188E) and novel (W394X) LPL gene mutations Ann Clin Biochem, January 1, 2008; 45(1): 102 - 105. [Abstract] [Full Text] [PDF]

				Y. Takeuchi, M. Takahashi, K. Sakano, M. Mutoh, N. Niho, M. Yamamoto, H. Sato, T. Sugimura, and K. Wakabayashi Suppression of N-nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis in hamsters by pioglitazone, a ligand of peroxisome proliferator-activated receptor {gamma} Carcinogenesis, August 1, 2007; 28(8): 1692 - 1696. [Abstract] [Full Text] [PDF]

				H. H. Wittrup, R. V. Andersen, A. Tybjaerg-Hansen, G. B. Jensen, and B. G. Nordestgaard Combined Analysis of Six Lipoprotein Lipase Genetic Variants on Triglycerides, High-Density Lipoprotein, and Ischemic Heart Disease: Cross-Sectional, Prospective, and Case-Control Studies from the Copenhagen City Heart Study J. Clin. Endocrinol. Metab., April 1, 2006; 91(4): 1438 - 1445. [Abstract] [Full Text] [PDF]

				V. Pruneta-Deloche, C. Marcais, L. Perrot, A. Sassolas, M. Delay, B. Estour, M. Lagarde, and P. Moulin Combination of Circulating Antilipoprotein Lipase (Anti-LPL) Antibody and Heterozygous S172 fsX179 Mutation of LPL Gene Leading to Chronic Hyperchylomicronemia J. Clin. Endocrinol. Metab., July 1, 2005; 90(7): 3995 - 3998. [Abstract] [Full Text] [PDF]

				O. Ziouzenkova, S. Perrey, L. Asatryan, J. Hwang, K. L. MacNaul, D. E. Moller, D. J. Rader, A. Sevanian, R. Zechner, G. Hoefler, et al. Lipolysis of triglyceride-rich lipoproteins generates PPAR ligands: Evidence for an antiinflammatory role for lipoprotein lipase PNAS, March 4, 2003; 100(5): 2730 - 2735. [Abstract] [Full Text] [PDF]

				M. Merkel, R. H. Eckel, and I. J. Goldberg Lipoprotein lipase: genetics, lipid uptake, and regulation J. Lipid Res., December 1, 2002; 43(12): 1997 - 2006. [Abstract] [Full Text] [PDF]

				L. A. Pennacchio, M. Olivier, J. A. Hubacek, R. M. Krauss, E. M. Rubin, and J. C. Cohen Two independent apolipoprotein A5 haplotypes influence human plasma triglyceride levels Hum. Mol. Genet., November 15, 2002; 11(24): 3031 - 3038. [Abstract] [Full Text] [PDF]

				A. A. Sethi, A. Tybjaerg-Hansen, M.-L. M. Gronholdt, R. Steffensen, P. Schnohr, and B. G. Nordestgaard Angiotensinogen Mutations and Risk for Ischemic Heart Disease, Myocardial Infarction, and Ischemic Cerebrovascular Disease: Six Case-Control Studies from the Copenhagen City Heart Study Ann Intern Med, May 15, 2001; 134(10): 941 - 954. [Abstract] [Full Text] [PDF]

				A. A. Sethi, B. G. Nordestgaard, B. Agerholm-Larsen, E. Frandsen, G. Jensen, and A. Tybjarg-Hansen Angiotensinogen Polymorphisms and Elevated Blood Pressure in the General Population : The Copenhagen City Heart Study Hypertension, March 1, 2001; 37(3): 875 - 881. [Abstract] [Full Text] [PDF]

				B. Agerholm-Larsen, A. Tybjarg-Hansen, P. Schnohr, R. Steffensen, and B. G. Nordestgaard Common Cholesteryl Ester Transfer Protein Mutations, Decreased HDL Cholesterol, and Possible Decreased Risk of Ischemic Heart Disease : The Copenhagen City Heart Study Circulation, October 31, 2000; 102(18): 2197 - 2203. [Abstract] [Full Text] [PDF]

				B. Agerholm-Larsen, B. G. Nordestgaard, R. Steffensen, G. Jensen, and A. Tybjarg-Hansen Elevated HDL Cholesterol Is a Risk Factor for Ischemic Heart Disease in White Women When Caused by a Common Mutation in the Cholesteryl Ester Transfer Protein Gene Circulation, April 25, 2000; 101(16): 1907 - 1912. [Abstract] [Full Text] [PDF]

				S. M. Clee, N. Bissada, F. Miao, L. Miao, A. D. Marais, H. E. Henderson, P. Steures, J. McManus, B. McManus, R. C. LeBoeuf, et al. Plasma and vessel wall lipoprotein lipase have different roles in atherosclerosis J. Lipid Res., April 1, 2000; 41(4): 521 - 531. [Abstract] [Full Text]

				R. Frikke-Schmidt, A. Tybjaerg-Hansen, R. Steffensen, G. Jensen, and B.o. G. Nordestgaard Apolipoprotein E genotype: epsilon32 women are protected while epsilon43 and epsilon44 men are susceptible to ischemic heart disease: The Copenhagen City Heart Study J. Am. Coll. Cardiol., April 1, 2000; 35(5): 1192 - 1199. [Abstract] [Full Text] [PDF]

				B. A. Marshall, K. Tordjman, H. H. Host, N. J. Ensor, G. Kwon, C. A. Marshall, T. Coleman, M. L. McDaniel, and C. F. Semenkovich Relative Hypoglycemia and Hyperinsulinemia in Mice with Heterozygous Lipoprotein Lipase (LPL) Deficiency. ISLET LPL REGULATES INSULIN SECRETION J. Biol. Chem., September 24, 1999; 274(39): 27426 - 27432. [Abstract] [Full Text] [PDF]

				H. Yagyu, S. Ishibashi, Z. Chen, J.-i. Osuga, M. Okazaki, S. Perrey, T. Kitamine, M. Shimada, K. Ohashi, K. Harada, et al. Overexpressed lipoprotein lipase protects against atherosclerosis in apolipoprotein E knockout mice J. Lipid Res., September 1, 1999; 40(9): 1677 - 1685. [Abstract] [Full Text]

				H. H. Wittrup, A. Tybjærg-Hansen, and B. G. Nordestgaard Lipoprotein Lipase Mutations, Plasma Lipids and Lipoproteins, and Risk of Ischemic Heart Disease : A Meta-Analysis Circulation, June 8, 1999; 99(22): 2901 - 2907. [Abstract] [Full Text] [PDF]

				H. H. Wittrup, A. Tybjærg-Hansen, R. Steffensen, S. S. Deeb, J. D. Brunzell, G. Jensen, and B. G. Nordestgaard Mutations in the lipoprotein lipase Gene Associated With Ischemic Heart Disease in Men : The Copenhagen City Heart Study Arterioscler. Thromb. Vasc. Biol., June 1, 1999; 19(6): 1535 - 1540. [Abstract] [Full Text] [PDF]

				H. E. Henderson, J. J. P. Kastelein, A. H. Zwinderman, E. Gagné, J. W. Jukema, P. W. A. Reymer, B. E. Groenemeyer, K. I. Lie, A. V. G. Bruschke, M. R. Hayden, et al. Lipoprotein lipase activity is decreased in a large cohort of patients with coronary artery disease and is associated with changes in lipids and lipoproteins J. Lipid Res., April 1, 1999; 40(4): 735 - 743. [Abstract] [Full Text]

				A. Tybjarg-Hansen, R. Steffensen, H. Meinertz, P. Schnohr, and B. G. Nordestgaard Association of Mutations in the Apolipoprotein B Gene with Hypercholesterolemia and the Risk of Ischemic Heart Disease N. Engl. J. Med., May 28, 1998; 338(22): 1577 - 1584. [Abstract] [Full Text] [PDF]

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nordestgaard, B. G. Articles by Tybjærg-Hansen, A. Search for Related Content PubMed PubMed Citation Articles by Nordestgaard, B. G. Articles by Tybjærg-Hansen, A.