Behre H M, Simoni M, Nieschlag E
Institute of Reproductive Medicine, University, Münster, Germany.
Clin Endocrinol (Oxf). 1997 Aug;47(2):237-40. doi: 10.1046/j.1365-2265.1997.2681067.x.
Leptin serves as a hormonal signal linking food intake and energy expenditure to fat mass. As significant effects of testosterone administration on body composition and adipose tissue have been described recently, we examined a possible association between serum levels of leptin and testosterone which has not been reported so far.
Three groups comprising a total of 58 adult age-matched males were included in this cross-sectional analysis by computer-assisted clinical database selection. Group 1 (n = 22) consisted of untreated hypogonadal patients with testosterone serum levels lower than 7 nmol/l. The inclusion criterion for Groups II (n = 20) and III (n = 16) was a serum testosterone level higher than 30 nmol/l. Group II involved hypogonadal patients under effective androgen substitution therapy; Group III comprised males without any endocrine disorder attending our clinic.
Morning blood samples were taken for determination of serum levels of leptin, testosterone, oestradiol and sex-hormone binding globulin (SHBG). Serum levels of leptin were measured by homologous radioimmunoassay, the other hormones by standard immunoassays.
No significant differences in serum leptin, serum testosterone, and body mass index (BMI) were detected between Group II (3.7 +/- 1.5 micrograms/l, 40.3 +/- 7.6 nmol/ l, 24.4 +/- 4.9 kg/m2, respectively (mean +/- SD)), and Group III (4.0 +/- 2.0 micrograms/l, 35.9 +/- 6.5 nmol/l, 24.8 +/- 2.6 kg/m2, respectively). However, hypogonadal patients of Group I who were selected for low testosterone serum levels (4.3 +/- 1.7 nmol/l) had significantly higher leptin serum levels of 18.8 +/- 9.7 micrograms/l (P < 0.001) and significantly higher BMI of 30.0 +/- 6.6 kg/m2 (P < 0.001). Multiple linear regression analysis revealed a significant independent association of leptin with testosterone serum levels (partial correlation coefficient = -0.84; P < 0.001) and with BMI (partial correlation coefficient = 0.44; P = 0.001), whereas serum levels of oestradiol and SHBG had no additional influence.
This study demonstrates a close association between serum levels of testosterone and leptin in males which has not been described previously. Serum testosterone levels could be an important contributor to the known gender difference in serum leptin levels which can be found even after correction for body composition. These findings might be of clinical relevance for testosterone substitution therapy of hypogonadal as well as ageing men.
瘦素作为一种激素信号，将食物摄入和能量消耗与脂肪量联系起来。由于最近已描述了睾酮给药对身体成分和脂肪组织有显著影响，我们研究了血清瘦素水平与睾酮之间可能存在的关联，这一关联迄今为止尚未见报道。
通过计算机辅助临床数据库筛选，将三组共58名年龄匹配的成年男性纳入本横断面分析。第一组（n = 22）由未经治疗的性腺功能减退患者组成，其血清睾酮水平低于7 nmol/l。第二组（n = 20）和第三组（n = 16）的纳入标准是血清睾酮水平高于30 nmol/l。第二组包括接受有效雄激素替代治疗的性腺功能减退患者；第三组由在我们诊所就诊且无任何内分泌疾病的男性组成。
采集早晨血样以测定血清瘦素、睾酮、雌二醇和性激素结合球蛋白（SHBG）水平。瘦素血清水平采用同源放射免疫测定法测量，其他激素采用标准免疫测定法测量。
第二组（分别为3.7±1.5微克/升、40.3±7.6 nmol/升、24.4±4.9千克/平方米（均值±标准差））和第三组（分别为4.0±2.0微克/升、35.9±6.5 nmol/升、24.8±2.6千克/平方米）之间，血清瘦素、血清睾酮和体重指数（BMI）未检测到显著差异。然而，因血清睾酮水平低而入选的第一组性腺功能减退患者，其瘦素血清水平显著更高，为18.8±9.7微克/升（P < 0.001），BMI也显著更高，为30.0±6.6千克/平方米（P < 0.001）。多元线性回归分析显示，瘦素与睾酮血清水平（偏相关系数 = -0.84；P < 0.001）以及与BMI（偏相关系数 = 0.44；P = 0.001）存在显著的独立关联，而雌二醇和SHBG的血清水平没有额外影响。
本研究表明男性血清睾酮水平与瘦素之间存在密切关联，这一关联此前未被描述。血清睾酮水平可能是血清瘦素水平已知性别差异的一个重要因素，即使在对身体成分进行校正后仍可发现这种差异。这些发现可能对性腺功能减退男性以及老年男性的睾酮替代治疗具有临床意义。
