Basal growth hormone levels are positively correlated with high-density lipoprotein cholesterol levels in women

Abstract

Previous studies in patients with either a deficiency or an excess of growth hormone (GH) yielded contradictory results on the regulation of lipoprotein metabolism by GH. In a cross-sectional study of 563 male and 126 female participants of the Prospective Cardiovascular Münster (PROCAM) Study, we determined biometric and demographic data, serum levels of total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo)A-I, A-II, and B, and unstimulated GH levels. The median of basal GH levels was higher in women than in men. Moreover, 44.2% of men but only 8.7% of women had basal GH levels less than the detection limit of 0.05 μg/L. The relationship between basal GH and lipoprotein metabolism was investigated by univariate and multivariate regression analysis of data from 315 men and 126 women with detectable basal GH levels. In men, GH correlated positively with HDL cholesterol and negatively with body mass index (BMI), age, and triglycerides. After multivariate analysis, the correlation with triglycerides remained independent of age and BMI. Among women, GH correlated positively with the use of hormonal contraception, HDL cholesterol, apoA-I, and apoA-II, and negatively with BMI, age, menopause, triglycerides, and apoB. With multivariate analysis, the positive correlations of GH with HDL cholesterol and apoA-I in women were independent of age, BMI, menopause, and oral contraception. We conclude that GH contributes to the regulation of HDL cholesterol levels. Moreover, in women the well-known effects of exogenous estrogen or estrogen loss on HDL metabolism may be partially mediated via GH.