Sex hormone-binding globulin is a major determinant of the lipid profile: the PRIME study

The prevalence of coronary heart disease is much higher in men than in women and sex hormones might play a role in these differences through their influence on the lipid profile. The aim of this cross-sectional study was to study the relationship between hormonal markers (total testosterone (TT), estradiol (E2), sex-hormone-binding globulin (SHBG)) and plasma lipids in a population-based sample. Subjects were 352 men, 50-59 years old, selected in France (Lille, Strasbourg and Toulouse) and Northern-Ireland (Belfast) who had questionnaires and a medical examination at baseline of the PRIME prospective study (1991-1993). Pearson correlation coefficients and Student's t tests were used to identify factors associated with plasma lipids. Multiple linear regression models were used for multivariate analyses, using triglycerides (TG) (log-transformed) and high density-lipoprotein cholesterol (HDL-C) as dependent variables. SHBG and TT were negatively correlated with TG (p < 0.0001 and p < 0.05, respectively) and positively correlated with HDL-C (p < 0.0001 and p < 0.01). E2 was positively correlated with TG (p < 0.05). No significant association was found between sex-hormones and LDL-C. In multiple linear regression analyses, SHBG remained independently associated negatively with TG (p < 0.01) and positively with HDL-C (p < 0.0001) after adjustment for centre of recruitment, age, body mass index, systolic blood pressure, smoking, alcohol intake and physical activity. After further adjustment for insulin, the association between SHBG and HDL-C remained highly significant (p < 0.0001). The association between SHBG and TG was weakened but remained also significant. Our results suggest that SHBG might to be a central protein in the hormonal regulation of the lipid profile.