Division of Pediatric Endocrinology, Department of Pediatrics, State University of New York at Buffalo, Buffalo, NY, USA.
Clin Endocrinol (Oxf). 2013 Apr;78(4):593-9. doi: 10.1111/cen.12018.
Obesity in adult males is associated with hypogonadotropic hypogonadism. We evaluated the effect of obesity on plasma testosterone concentrations in pubertal and post-pubertal young males.
Morning fasting blood samples were obtained from 25 obese [body mass index (BMI) ≥95th percentile] and 25 lean (BMI <85th percentile) males between the ages 14-20 years with Tanner staging ≥4. Total (TT) and free testosterone (FT) and estradiol concentrations were measured by liquid chromatography tandem mass spectrometry and equilibrium dialysis. Free testosterone was also calculated using SHBG and albumin. C-reactive protein (CRP), insulin and glucose concentrations were measured and homoeostasis model of insulin resistance (HOMA-IR) was calculated.
After controlling for age and Tanner staging, obese males had a significantly lower total testosterone (10·5 vs 21·44 nmol/l), free testosterone (0·22 vs 0·39 nmol/l) and calculated free testosterone (0·26 vs 0·44 nmol/l) concentrations as compared to lean males (P < 0·001 for all). Obese males had higher CRP concentrations (2·8 vs 0·8 mg/l; P < 0·001), and HOMA-IR (3·8 vs 1·1; P < 0·001) than lean males. Free testosterone concentrations were positively related to age and negatively to BMI, HOMA-IR and CRP concentrations. Total and free estradiol concentrations were significantly lower in males with subnormal testosterone concentrations.
Testosterone concentrations of young obese pubertal and post-pubertal males are 40-50% lower than those with normal BMI. Obesity in young males is associated with low testosterone concentrations, which are not secondary to an increase in estradiol concentrations. Our results need to be confirmed in a larger number of subjects.
成年男性肥胖与促性腺激素低下性性腺功能减退症有关。我们评估了肥胖对青春期和青春期后年轻男性血浆睾酮浓度的影响。
从年龄在 14-20 岁、Tanner 分期≥4 的 25 名肥胖（BMI≥第 95 百分位数）和 25 名瘦（BMI<第 85 百分位数）男性中采集清晨空腹血样。使用液相色谱串联质谱法和平衡透析法测定总（TT）和游离睾酮（FT）和雌二醇浓度。游离睾酮也用 SHBG 和白蛋白计算。测量 C 反应蛋白（CRP）、胰岛素和葡萄糖浓度，并计算胰岛素抵抗的稳态模型（HOMA-IR）。
在控制年龄和 Tanner 分期后，肥胖男性的总睾酮（10·5 与 21·44 nmol/l）、游离睾酮（0·22 与 0·39 nmol/l）和计算的游离睾酮（0·26 与 0·44 nmol/l）浓度明显低于瘦男性（所有 P<0·001）。肥胖男性的 CRP 浓度（2·8 与 0·8 mg/l；P<0·001）和 HOMA-IR（3·8 与 1·1；P<0·001）高于瘦男性。游离睾酮浓度与年龄呈正相关，与 BMI、HOMA-IR 和 CRP 浓度呈负相关。睾丸激素浓度低于正常的男性的总睾酮和游离雌二醇浓度明显降低。
年轻肥胖青春期和青春期后男性的睾酮浓度比正常 BMI 低 40-50%。年轻男性肥胖与低睾酮浓度有关，而不是由于雌二醇浓度升高所致。我们的结果需要在更多的研究对象中得到证实。
