Objective: Androgen deficiency is common in aging males and may have unfavourable health consequences. Large-scale studies suggested low testosterone level might increse mortality and morbidity in ageing males. However, young men with low testosterone level might be neglected. Recent studies reported young men with infertility may have reduced testosterone level. To investigate the incidence of androgen deficiency in males with infertility and possible factors affecting the low testosterone level.
Methods: Between January 2011 and December 2012, 407 men with infertility caused by varicocele (VC), obstructive azoospermia (OA) and nonobstructive azoospermia (NOA) in our center were included. The number of men in each group of OA, NOA and VC was 141, 97 and 169, respectively. All the eligible patients underwent a serum testosterone assessment by a single morning blood draw (between 8:00 to noon) to test for concentration of the total testosterone. All serum samples were determined by radioimmunoassay in our andrology laboratory. Androgen deficiency was defined as having a total testosterone level less than 300 ng/dL.
Results: The mean age was (30.4±5.8) years. The mean testosterone level was (4.18±1.64) ng/dL (range 0.30 to 11.32 ng/dL). The overall incidence of androgen deficiency was 26.5% (108/407). The incidences of androgen deficiency in NOA, OA and VC groups were 40.2% (39/97), 19.1% (27/141) and 24.9% (42/169), respectively, which were significantly higher in the NOA than in the VC and OA groups (P < 0.001). The incidences had no difference between the VC and OA groups (P=0.229). Univariate analysis revealed the cause of infertility, FSH and the mean testis volume as possible affecting factors for androgen deficiency. However, on multivariate analysis the only cause of infertility was an independent predictor. The incidence of androgen deficiency was the highest in the NOA group [OR 0.492 (95% confidence interval 0.288-0.840)].
Conclusion: NOA and varicocele might be risk factors of androgen deficiency. Young men with NOA may have a higher possibility of low testosterone level. Testosterone level should be followed up after NOA and varicocele treatment. Androgen deficiency should be assessed in males with infertility in clinical practice.
目的: 调查不育症男性雄激素缺乏的发生率及其可能影响因素。
方法: 选择2011年1月至2012年12月因精索静脉曲张(varicocele, VC)、梗阻性无精子症(obstructive azoospermia, OA)和非梗阻性无精子症(nonobstructive azoospermia, NOA)入北京大学第一医院泌尿外科手术治疗患者的病例资料进行回顾性分析，所有患者在治疗前检查血清总睾酮水平，OA、NOA和VC患者数量分别为141，97和169例，所有患者均在上午检测总睾酮浓度。所有样本在男科实验室采用放射免疫方法检测总睾酮水平，低于300 ng/dL定义为雄激素缺乏。
结果: 共收集到病例407例，平均年龄(30.4±5.8)岁，平均睾酮水平(4.18±1.64) ng/dL (0.30~11.32 ng/dL)。总体雄激素缺乏的发生率为26.5%(108/407)，在NOA、OA和VC组的雄激素缺乏的发生率分别为40.2%(39/97)、19.7% (27/141)和24.9%(42/169)。NOA和VC组雄激素缺乏的发生率高于OA组(P < 0.001)，而VC组和OA组的雄激素缺乏发生率差异无统计学意义(P=0.229)，多因素分析发现不育症的原因是雄激素缺乏的独立预测因素。
结论: NOA和VC可能是雄激素缺乏的危险因素，NOA的年轻男性出现雄激素水平低下的可能性更大，NOA和VC治疗后应该随访睾酮水平。在临床中对不育症男性应该评估是否有雄激素缺乏存在。
Keywords: Androgen efficiency; Azoospermia; Infertility; Varicocele.