title: Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China: a cross-sectional study.
abstract: 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 ± 3.1 years) were enrolled. The individuals were grouped as CAG short (CAG S ) if they harbored repeat length of ≤ 20 or as CAG long (CAG L ) 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.
authors.forename: Yan-Min
authors.initials: YM
authors.lastname: Ma
authors.forename: Kai-Jie
authors.initials: KJ
authors.lastname: Wu
authors.forename: Liang
authors.initials: L
authors.lastname: Ning
authors.forename: Jin
authors.initials: J
authors.lastname: Zeng
authors.forename: Bo
authors.initials: B
authors.lastname: Kou
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Xie
authors.forename: Zhen-Kun
authors.initials: ZK
authors.lastname: Ma
authors.forename: Xin-Yang
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Urology, First Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Yong-Guang
authors.initials: YG
authors.lastname: Gong
authors.affiliation: Department of Urology, First Affiliated Hospital of Medical School, Xi'an Jiaotong University; Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of the People's Republic of China, Xi'an, China.
authors.forename: Da-Lin
authors.initials: DL
authors.lastname: He
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics; D002681:China; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008297:Male; D010413:Penis / Q000033:anatomy & histology*; D011110:Polymorphism, Genetic; D011388:Prolactin / Q000097:blood; D011944:Receptors, Androgen / Q000235:genetics*; D013739:Testosterone / Q000097:blood; D018911:Trinucleotide Repeats; D055815:Young Adult
chemical_list: C410798:AR protein, human; D012739:Gonadal Steroid Hormones; D011944:Receptors, Androgen; D013739:Testosterone; D011388:Prolactin