Campbell Benjamin C, Gray Peter B, Eisenberg Dan T A, Ellison Peter, Sorenson Michael D
Department of Anthropology, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA.
Int J Androl. 2009 Apr;32(2):140-8. doi: 10.1111/j.1365-2605.2007.00825.x. Epub 2007 Nov 26.
To determine the population variation in the androgen receptor (AR) and its association with body composition in a subsistence population, we sampled 87 settled and 65 nomadic males ages 20+ among the Ariaal of northern Kenya. Anthropometric measures included height, body mass index, fat-free mass (FFM), upper arm muscle plus bone area (AMPBA), % body fat (%BF), suprailliac skinfold (SISF), and waist-to-hip ratio. Salivary testosterone (T) was determined from both morning (Am T) and afternoon (Pm T) samples. Hair roots were obtained for genotyping AR CAG repeat length. AR CAG repeat length did not vary between the two sub-groups (overall value = 22.6 +/- 3.1). Multiple regression models, controlling for age and residence, indicate that Pm T was positively associated with all measures of body composition. AR CAG repeat length was a significant positive predictor of height, FFM, %BF, SISF and waist circumference. There was a significant negative Pm T by AR CAG repeat length interaction in predicting all anthropometric measures but AMPBA. These findings provide evidence for population variation in AR CAG repeat length and suggest that both T and AR CAG length play a role in body composition in this extremely lean population.
为了确定雄激素受体（AR）在自给自足人群中的群体差异及其与身体成分的关联，我们在肯尼亚北部的阿里亚尔族中，对87名20岁及以上的定居男性和65名游牧男性进行了采样。人体测量指标包括身高、体重指数、去脂体重（FFM）、上臂肌肉加骨骼面积（AMPBA）、体脂百分比（%BF）、髂上皮肤褶厚度（SISF）和腰臀比。分别从早晨（上午T）和下午（下午T）的样本中测定唾液睾酮（T）。采集发根用于AR CAG重复序列长度的基因分型。两个亚组之间的AR CAG重复序列长度没有差异（总体值 = 22.6 +/- 3.1）。在控制年龄和居住地的多元回归模型中，下午T与所有身体成分测量指标呈正相关。AR CAG重复序列长度是身高、FFM、%BF、SISF和腰围的显著正预测因子。在预测除AMPBA之外的所有人体测量指标时，下午T与AR CAG重复序列长度之间存在显著的负交互作用。这些发现为AR CAG重复序列长度的群体差异提供了证据，并表明T和AR CAG长度在这个极度消瘦的人群的身体成分中都发挥着作用。
