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We have shown previously that a hepatic lipase allele (designated –514T) is common among African Americans and contributes to low hepatic lipase activity in this population. To identify other hepatic lipase alleles associated with low hepatic lipase activity in this population, the coding region and intron–exon boundaries of the hepatic lipase gene were sequenced in 20 African American men with low hepatic lipase activity. Two polymorphisms (N193S and L334F) were associated with low post-heparin plasma hepatic lipase activity and were much more common in African Americans than in whites. This finding, together with our previous data on the –514T allele, indicates that at least three different hepatic lipase polymorphisms associated with low hepatic lipase activity are common among African Americans. Analysis of hepatic lipase haplotypes revealed that 97% of African Americans have at least one hepatic lipase allele that is associated with low hepatic lipase activity.—Nie, L., S. Niu, G. L. Vega, L. T. Clark, A. Tang, S. M. Grundy, and J. C. Cohen. Three polymorphisms associated with low hepatic lipase activity are common in African Americans.

The -514 polymorphism in the hepatic lipase gene (LIPC) is associated with decreased hepatic lipase activity. In the present study, the interaction between body mass index (BMI), the -514 polymorphism, and hepatic lipase activity was examined in 118 white men and in 51 African American men. BMI was significantly positively correlated with hepatic lipase activity in both populations. BMI was similar in men with genetic differences in hepatic lipase activity, indicating that high hepatic lipase activity did not cause increased BMI. The data therefore suggest that high BMI leads to increased hepatic lipase activity. The actions of BMI and the -514 polymorphism on hepatic lipase activity appear to be additive and independent, rather than synergistic. This finding indicates that hepatic lipase activity is a multifactorial trait, determined in part by polymorphism within the LIPC gene as well as by factors that influence BMI.—Nie, L., J. Wang, L. T. Clark, A. Tang, G. L. Vega, S. M. Grundy, and J. C. Cohen. Body mass index and hepatic lipase gene (LIPC) polymorphism jointly influence postheparin plasma hepatic lipase activity. J. Lipid Res. 1998. 39: 1127–1130.

Plasma high density lipoprotein cholesterol (HDL-C) concentrations are higher in African American men than in white men, but the mechanism(s) responsible for this ethnic difference has not been elucidated. This study examined the relationship between hepatic lipase activity, plasma HDL-C concentrations, and a hepatic lipase polymorphism (–514T) in African American and white American men. Consistent with previous reports, plasma HDL-C concentrations were significantly higher in African American men than in white American men. Mean post-heparin plasma hepatic lipase activity was significantly lower in African American than in white American men (27 ± 12 vs. 44 ± 17 mmol • h–1 •l–1, P < 0.001). The –514T hepatic lipase allele was associated with low hepatic lipase activity in both populations, and was 3-fold more common among African Americans than white Americans. Taken together, these data suggest that genetic differences in hepatic lipase activity contribute to the differences in plasma HDL-C concentrations between African American men and white American men.—Vega, G. L., L. T. Clark, A. Tang, S. Marcovina, S. M. Grundy, and J. C. Cohen. Hepatic lipase activity is lower in African American men than in white American men: effects of 5′ flanking polymorphism in the hepatic lipase gene (LIPC). J. Lipid Res. 1998. 39: 228–232.