Andrology Department, Concord Hospital, Clayton, Vic., Australia.
Clin Endocrinol (Oxf). 2012 Nov;77(5):755-63. doi: 10.1111/j.1365-2265.2012.04432.x.
To determine serum concentrations, intra-individual variability and impact of age-related co-morbidities on serum testosterone (T), dihydrotestosterone (DHT), estradiol (E(2)) and estrone (E(1)) in older men.
Observational, repeated measures study.
Men (n = 325) with 40 years and older self-reporting very good or excellent health.
Standardized history, physical examination and collection of nine blood samples at fixed time intervals were measured over 3 months (three at 20 min intervals on days 1 (fasting) and 2 (non-fasting), one at days 7, 30 and 90). Serum T, DHT, E(2) and E(1) (n = 2900, > 99% of scheduled samples) measured by liquid chromatography-tandem mass spectrometry (LC-MS) were analysed by linear mixed model analysis with fasting, age and obesity as covariables.
Mean serum T did not vary with age (P = 0·76) but obesity (-0·35 nM per body mass index (BMI) unit, P < 0·0001) and ex-smoker status (-1·6 nM, P < 0·001) had significant effects. Serum DHT was increased with age (+0·011 nM per year, P = 0·001) but decreased with obesity (-0·05 nM per BMI unit, P < 0·0001). Serum E(2) did not vary with age (P = 0·31) or obesity (P = 0·12). Overnight fasting increased (by 9-16%, all P < 0·001) and reduced variability in morning serum T, DHT, E(2) and E(1). Non-fasting serum T and DHT were stable over time (day, week, month or 3 months; P > 0·28).
Serum T, DHT and E(2) displayed no decrease associated with age among men over 40 years of age who self-report very good or excellent health although obesity and ex-smoking status were associated with decreased serum androgens (T and DHT) but not E(2). These findings support the interpretation that the age-related decline in blood T accompanying non-specific symptoms in older men may be due to accumulating age-related co-morbidities rather than a symptomatic androgen deficiency state.
确定血清浓度、个体内变异性以及年龄相关合并症对 40 岁以上男性血清睾酮（T）、二氢睾酮（DHT）、雌二醇（E（2））和雌酮（E（1））的影响。
观察性、重复测量研究。
自我报告身体非常健康或极好的 40 岁及以上男性（n=325）。
在 3 个月内进行标准化的病史、体格检查和 9 次定时采血（第 1 天（禁食）和第 2 天（非禁食）每 20 分钟一次采血 3 次，第 7、30 和 90 天各采血 1 次）。通过液相色谱-串联质谱（LC-MS）测量的血清 T、DHT、E（2）和 E（1）（n=2900，超过 99%的预定样本），用线性混合模型分析，以禁食、年龄和肥胖为协变量。
血清 T 浓度与年龄无关（P=0.76），但肥胖（每 BMI 单位增加 0.35 nM，P<0.0001）和曾吸烟者状态（减少 1.6 nM，P<0.001）有显著影响。血清 DHT 随年龄增长而增加（每年增加 0.011 nM，P=0.001），但随肥胖而减少（每 BMI 单位减少 0.05 nM，P<0.0001）。血清 E（2）与年龄（P=0.31）或肥胖（P=0.12）无关。夜间禁食使早晨血清 T、DHT、E（2）和 E（1）升高（9-16%，均 P<0.001）并降低了其变异性。非禁食血清 T 和 DHT 在时间（天、周、月或 3 个月）上稳定（P>0.28）。
40 岁以上自我报告身体非常健康或极好的男性，其血清 T、DHT 和 E（2）水平与年龄无关，尽管肥胖和曾吸烟者状态与血清雄激素（T 和 DHT）降低有关，但与 E（2）无关。这些发现支持这样的解释，即与年龄相关的非特异性症状相关的老年男性血 T 水平下降可能是由于年龄相关合并症的积累，而不是症状性雄激素缺乏状态。
