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 (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.

Revisiting the relationships of 2D:4D with androgen receptor (AR) gene and current testosterone levels: Replication study and meta‐analyses

“…Relationship between the length of AR (CAG)n and current testosterone levels is somewhat inconsistent referring to the previous studies in males: The four studies indicate that the length is positively correlated with the levels (De Naeyer et al, ; Ma et al, ; Manuck et al, ; Stanworth, Kapoor, Channer, & Jones, ); another study, however, demonstrates a significant negative correlation between them (Mosaad, Shahin, Elkholy, Mosbah, & Badawy, ); and another 15 studies report there is no a significant correlation between them at all (Aluja et al, ; Durdiaková et al, ; Durdiaková et al, ; Eisenegger, Kumsta, Naef, Gromoll, & Heinrichs, ; Gettler et al, ; Goutou, Sakka, Stakias, Stefanidis, & Koukoulis, ; Hampson & Sankar, ; Kubranska et al, ; Lapauw, Goemaere, Crabbe, Kaufman, & Ruige, ; Nowak, Diamond, Land, & Moffat, ; Ryan et al, ; Sankar & Hampson, ; Schneider et al, ; Schneider, Zitzmann, Gromoll, Ladwig, & Berger, ; Stiger et al, ). Regarding the same relationship analyzed by previous studies for females, two studies indicate the length is positively correlated with the levels (Peng et al, ; Skrgatic, Baldani, Cerne, Ferk, & Gersak, ); such relationship, however, is significantly negative (Brum et al, ; Jaaskelainen et al, ); or not significant (Durdiaková et al, ; Jaaskelainen, Korhonen, Voutilainen, Hippelainen, & Heinonen, ; Nowak et al, ).…”

Polymorphisms of androgens‐related genes and idiopathic male infertility in Turkish men

“…In our study, short (≤22 CAG) and long CAG (>22 CAG) repeat groups showed no significant difference in the infertility risk. On the The association of CAG repeats with the serum levels of LH, FSH, testosterone and testicular volume demonstrates contradictory results in several studies, most of which did not find a significant correlation between several hormones and CAG repeats (Badran et al, 2009;Ma et al, 2014;Sasagawa et al, 2001). In our study, we also could not find any correlations between the CAG repeat expansion and levels of testosterone, LH and FSH.…”