Objective

A rare mutation in low density lipoprotein receptor-related protein 6 gene (LRP6) was identified as the primary molecular defect underlying monogenic form of coronary artery disease. We hypothesised that common variants in LRP6 could predispose subjects to elevated LDL-cholesterol (LDL-C).

Methods and Results

12 common (minor allele frequency ≥0.1) single nucleotide polymorphisms in LRP6 were genotyped in 703 individuals from 213 Polish pedigrees (Silesian Cardiovascular Study families). The family-based analysis revealed that the minor allele of rs10845493 clustered with elevated LDL-C in offspring more frequently than expected by chance (p=0.0053). The quantitative analysis restricted to subjects free of lipid-lowering treatment confirmed the association between rs10845493 and age-, sex- and BMI-adjusted circulating levels of LDL-C in families as well as 2 additional populations - 218 unrelated subjects from Silesian Cardiovascular Study replication panel and 1138 individuals from Young Men Cardiovascular Association cohort (p=0.0268, p=0.0476 and p=0.0472, respectively). In the inverse variance weighted meta-analysis of the 3 populations each extra minor allele copy of rs10845493 was associated with 0.14 mmol/L increase in age-, sex- and BMI-adjusted LDL-C (SE=0.05, p=0.0038).

Conclusions

Common polymorphism in the gene underlying monogenic form of coronary artery disease impacts on risk of LDL-C elevation.

Objectives

Men show higher rates of cardiovascular morbidity and mortality than pre-menopausal women and this sexual dimorphism may be related to sex-specific effects of sex steroids on cardiovascular risk factors. Unlike androgens, estrogens were not extensively investigated in relation to cardiovascular phenotypes in men.

Methods

We examined associations of estradiol and estrone and their precursors (total testosterone and androstenedione) with traditional cardiovascular risk factors (lipids, blood pressure, body mass) in 933 young (median age – 19 years), apparently healthy Polish men.

Results

Total estradiol was associated with total cholesterol (p=0.006) and HDL-cholesterol (p<0.001) and estrone showed the strongest associations with both total cholesterol (p<0.001) and LDL-cholesterol (p<0.001) in the unadjusted ANOVA analysis. In the multivariable adjusted models in which other independent variables were held as constant one standard deviation increase in estradiol level was associated with 6%-standard deviation increase in total cholesterol (standardized B=0.06, p=0.038) and 6%-standard deviation decrease in HDL-cholesterol (standardized B=-0.06, p=0.036). An increase in estrone levels by one standard deviation was associated with respective 12%- and 13%-standard deviation increases in total cholesterol (standardized B=0.12, p<0.001) and LDL-cholesterol levels (standardized B=0.12, p<0.001) after controlling for other predictors of lipids. Estrone correlated linearly with androstenedione (r=0.28, p<0.001) but there was no correlation between estradiol and testosterone. Estrogens retained their independent associations with lipids after adjustment for their biochemical precursors in the multivariable analysis.

Conclusions

Increased levels of estrogens are associated with unfavourable lipid profile in men and that this association is apparent early in life, before cardiovascular disease manifestations.

BACKGROUND

Men exhibit higher risk of nondiabetic renal diseases than women. This male susceptibility to renal disease may be mediated by gender-specific factors such as sex hormones.

METHODS

We have undertaken a cross-sectional examination of associations between renal function (creatinine clearance estimated based on Cockcroft–Gault equation) and circulating levels of sex steroids (total testosterone, total estradiol, estrone, androstenedione, dehydroepiandrosterone sulfate (DHEA-S), and dihydrotestosterone) in 928 young (mean age: 18.5 ± 1.2 years) men.

RESULTS

Both androstenedione and DHEA-S showed inverse linear associations with renal function in the crude analysis of lean men (those with body mass index (BMI) less than median). However, only DHEA-S retained its association with renal function in lean subjects after adjustment—assuming no changes in other independent variables 1 s.d. increase in DHEA-S was associated with 13%-s.d. decrease in creatinine clearance (P = 0.004). Testosterone decreased across tertiles of creatinine clearance only in the crude analysis of nonlean (BMI greater than median) subjects (P < 0.001). The adjusted regression analysis that assumed no changes in other independent variables showed that 1 s.d. increase in total testosterone was associated with 11%-s.d. decrease in creatinine clearance of nonlean men (P = 0.006). Factor analysis confirmed an inverse association of renal function with both sex steroids and a different pattern of their loadings on glomerular filtration–related factors in lean (DHEA-S) and nonlean (testosterone) subjects.

CONCLUSIONS

Our data may suggest that androgens are inversely associated with estimated renal function in apparently healthy men without history of cardiovascular disease.