Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging.
Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging.
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DOI：
10.1210/jcem.86.2.7219
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发表时间：
2001-02
期刊：
影响因子：
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通讯作者：
S. Harman;E. Metter;J. Tobin;J. Pearson;M. Blackman
中科院分区：
文献类型：
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作者：
S. Harman;E. Metter;J. Tobin;J. Pearson;M. Blackman
许多研究表明，男性的总睾酮和/或游离睾酮 (T) 水平随着年龄的增长而出现横断面（以及两项小型纵向研究）下降。 T 下降在多大程度上是衰老过程本身的结果，而不是慢性疾病、药物使用和其他与年龄相关的因素，仍然存在争议。衰老导致 T 水平与性腺功能减退症一致的频率也尚未确定。这些问题与 T 替代疗法在老年男性中的潜在用途有关，因为衰老和性腺功能减退症共同导致骨骼和去脂体重以及肌肉力量的减少，以及总脂肪和腹部脂肪的增加。我们通过 RIA 测量了巴尔的摩老龄纵向研究中 890 名男性的储存样本中的 T 和性激素结合球蛋白 (SHBG)。使用混合效应模型，我们发现年龄和采样日期对降低 T 水平有独立影响。在补偿日期效应（调查表明这是人为因素）后，我们观察到年龄对 T 和游离 T 指数（游离 T 指数 = T/SHBG）的显着、独立、年龄不变的纵向影响，平均变化为 -0.124 nmol/L.yr 和 -0.0049 nmol T/nmol SHBG.yr。 T，但不是游离T指数，也随着体重指数的增加而下降。使用 β 阻滞药物与较高的 T 和较高的游离 T 指数水平相关。使用总 T 标准，性腺 T 水平低下的发生率在 60 岁以上男性中增加到约 20%，在 70 岁以上为 30%，在 80 岁以上为 50%，当采用自由 T 指数标准时，比例甚至更高。我们对独立于健康因素、与年龄相关的 T 和游离 T 纵向下降的观察结果表明，对老年男性进行 T 替代的进一步研究（可能针对血清 T 浓度最低的人群）是合理的。
Many studies have shown cross-sectional (and two small studies, longitudinal) declines in total and/or free testosterone (T) levels, with age, in men. The extent to which decline in T is the result of the aging process per se, as opposed to chronic illness, medication use, and other age-related factors, remains controversial. The frequency with which aging leads to T levels consistent with hypogonadism has also not been defined. These issues bear on the potential use of T replacement in aging men, because aging and hypogonadism have, in common, reduced bone and lean body mass and muscle strength and increased total and abdominal fat. We measured T and sex hormone-binding globulin (SHBG), by RIA, in stored samples from 890 men in the Baltimore Longitudinal Study on Aging. Using a mixed-effects model, we found independent effects of age and date of sampling to reduce T levels. After compensating for date effects, which investigation suggested was artifactual, we observed significant, independent, age-invariant, longitudinal effects of age on both T and free T index (free T index = T/SHBG), with an average change of -0.124 nmol/L.yr and -0.0049 nmol T/nmol SHBG.yr. T, but not free T index, also decreased with increasing body mass index. Use of beta-blocking drugs was associated with higher T and higher free T index levels. Using total T criteria, incidence of hypogonadal T levels increased to about 20% of men over 60, 30% over 70 and 50% over 80 yr of age, and even greater percentages when free T index criteria were employed. Our observations of health factor independent, age-related longitudinal decreases in T and free T, resulting in a high frequency of hypogonadal values, suggest that further investigation of T replacement in aged men, perhaps targeted to those with the lowest serum T concentrations, are justified.