Objective: The primary aim of this study was to investigate the association between the vitamin D receptor polymorphisms rs2228570 (Fok1) and rs731236 (TaqI) and LH and FSH levels in relation to anabolic androgenic steroid (AAS) use.
Results: Two cohorts were analyzed. Cohort 1 comprised healthy volunteers given single supra-physiological doses of 500 mg testosterone (n = 25). Cohort 2 comprised 45 self-reporting AAS users. Healthy volunteers homozygous for the C-allele of the Fok1 polymorphism exhibited 30% higher LH levels than T-carriers at baseline (p = 0.04) and twice the levels 14 days after testosterone administration (p = 0.01). AAS users homozygous for the C-allele had four times higher LH levels than TT-individuals (p < 0.05). FSH levels were not associated with Fok1 polymorphism, nor were LH and FSH levels associated with the TaqI polymorphism. In conclusion, there is an association between LH levels and the Fok1 VDR polymorphism and this difference is even more pronounced in AAS users and subjects with suppressed LH levels.
Keywords: Anabolic androgenic steroid; FSH; Hypogonadism; LH; Vitamin D receptor; rs2228570; rs731236.