Endocrine Abstracts

Androgen insensitivity leads to a defect of virilization in karyotypic males despite supraphysiologic androgen levels. Because of an impaired regulatory mechanism of the gonadotropin-androgen axis, both LH and T in serum may be elevated, leading to a distinctively high value of the LH×T multiplication product, which has been termed as the androgen sensitivity index (ASI). The aim of our present study was to investigate a cohort of young males with light decrease in penile size for impaired ASI. About 177 nearly healthy post-pubertal boys at the age of 16 up to 26 years old, permanently living on the territory of the Republic of Belarus, were examined to evaluate their physical, sexual and hormonal state (TSH, FSH, T, Free T, PRL, SHBH, E2). ASI has been calculated according to the standard formula, the normal range reported by Hiort et al., ranging from 1930–9970 ng*IU/l² (mean, 15 590 ng*IU/l²), was used for comparison. Penile size of ≥9.5 cm had been determined in 22.6% (40 from 177), 8.5–9.5 cm in 36.2% (60 from 177) and ≤8.5 cm in 41.2% (73 from 177) of all examined. The 3-rd group was considered to have subnormal penile size as it was less, then reported by Wessells et al. (8.85–10.7 cm) for European population, while the 1-st group was taken as control. The average ASI index in 3-rd group was 31 767 ng*IU/l² (10 000–83 950) while in control group 24 845 ng*IU/l² (4393–39 480), P<0.0001. In the 3-rd group also were determined evident elevated levels of LH, T and Free T in comparison with the control group. That means, that androgen insensitivity could be named as one of the leading reasons for subnormal penile size forming in young belarussian men and high frequency of that phenomenon could not just be considered as a national particularity.