Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China： a cross-sectional study

• Published in: Asian journal of andrology 2014-05, Vol.16 (3), p.478-481
• Main Authors: Ma, Yan-Min, Wu, Kai-Jie, Ning, Liang, Zeng, Jin, Kou, Bo, Xie, Hong-Jun, Ma, Zhen-Kun, Wang, Xin-Yang, Gong, Yong-Guang, He, Da-Lin
• Format: Article
• Language: English
• Subjects: Adult; androgen receptor; CAG repeat; testosterone; prolactin; penile length; Androgens; Asian Continental Ancestry Group - genetics; CAG重复; China; Confidence intervals; Deoxyribonucleic acid; DNA; Genetic aspects; Gonadal Steroid Hormones - blood; Hormones; Humans; Infertility; Male; Original; Penis - anatomy & histology; Polymorphism, Genetic; Prolactin - blood; Receptors, Androgen - genetics; Statistical analysis; Testosterone - blood; Trinucleotide Repeats; Young Adult; Young adults; 中国西北; 序列多态性; 序列长度; 性激素; 成年; 阴茎; 雄激素受体
• ISSN: 1008-682X; 1745-7262
• DOI: 10.4103/1008-682X.124560

This study aimed to investigate the correlations among androgen receptor （AR） CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and fifty-three healthy men （aged 22.8 ± 3.1years） were enrolled. The individuals were grouped as CAG short （CAGs） if they harbored repeat length of 〈20 or as CAG long （CAGL） if their CAG repeat length was 〉20. Body height/weight, penile length and other parameters were examined and recorded by the specified physicians; CAG repeat polymorphism was determined by the polymerase chain reaction （PCR） method; and the serum levels of the sex hormones were detected by radioimmunoassay. Student＇s t-test or linear regression analysis was used to assess the associations among AR CAG repeat polymorphism, sex hormones and penile length. This investigation showed that the serum total testosterone （T） level was positively associated with the AR CAG repeat length （P = 0.01）; whereas, no significant correlation of T or AR CAG repeat polymorphism with the penile length was found （P = 0.593）. Interestingly, an inverse association was observed between serum prolactin （PRL） levels and penile length by linear regression analyses （β = -0.024, P = 0.039, 95% confidence interval （CI）： -0.047, 0）. Collectively, this study provides the first evidence that serum PRL, but not T or AR CAG repeat polymorphism, is correlated with penile length in the Han adult population from northwestern China.