Η επίδραση του πολυμορφισμού των οιστρογονικών υποδοχέων στα επίπεδα των στερεοειδών ορμονών και των λιπιδίων αίματος στους άνδρες ; Associations of estrogen receptor polymorphisms with sex hormones and lipid levels in men.

Objective: Estrogens play an important role in male physiology. We investigated the possible association of four single nucleotide polymorphisms in Estrogen Receptor α and Estrogen Receptor β genes with circulating levels of sex steroids and lipid levels in men.Design and Methods: SHBG, total and calculated free testosterone (TT and cal FT), estradiol (E2) and free Estradiol (FE2 ) Lipids, glucose, insulin and HOMA-IR were determined in a population-based cohort of 170 apparently healthy Greek men. Body mass index (BMI), waist circumference (WC) and percentage of body fat (%fat) content were measured in all participants. Genotyping for the PvuII and XbaI polymorphisms of the ESR1 gene and for the RsaI and AluI polymorphisms of the ESR2 gene was performed.Results: PvuII showed an association with E2 levels [median (IQR) pp 58.5 (42.1-73.4) pg/ml vs. Pp 48.8 (42.9-60.1) and PP 57.7 (44-70.5), p=0.032], and with %fat [mean±SD pp 24.6±5.3 vs Pp 22.4±5.2 and PP 21.2±6.7, p=0.044], after adjustment for age and WC. Furthermore, the effect of PvuII on E2 was independent of %fat (p=0.038).A synergistic effect of the two ESR1 polymorphisms on E2 (p=0.023), FE2 (p=0.03) and %fat (p=0.004) was present. Finally, a synergistic effect of the ESR1 and ESR2 genes on TT (p=0.009), independent of age, WC and %fat also emerged.Associations of AluI with LDL-Chol (mean±SD, aa 4.3±1.1 vs. Aa 3.7±1.0 and ΑΑ 4.2±1.1, p=0.023) and RsaI with HOMA-IR [median(IQR) RR 1.55(0.88-2.49) vs. Rr/rr 1.69(0.72-2.29), p=0.032] were found. Synergistic effects of RsaI and AluI of ESR2 gene on LDL-Chol levels, %fat and WC, as well as a synergistic effect of both ESR1 and ESR2 genes on levels of T-Chol (p=0.01) and LDL-Chol (p=0.027) were also shown. These findings remained significant after adjustment for potential confounders.Significant independent associations of PvuII with %fat (mean±SD, pp 24.6±5.3 vs Pp 22.4±5.2 and PP 21.2±6.7, p=0.044), and RsaI with % fat (RR 22.6 ±5.5 vs. Rr/rr 25.2 ±6.3, p=0.015) and WC (mean±SD RR 97.4 ±10.4 vs. ...