Yarasheski K E, Zachwieja J J, Horgan M M, Powderly W G, Santiago J V, Landt M
Division of Endocrinology, Washington University School of Medicine, St Louis, MO 63110, USA.
Metabolism. 1997 Mar;46(3):303-5. doi: 10.1016/s0026-0495(97)90258-4.
The product of the obese gene (ob) is the protein leptin, which is synthesized in and secreted from adipocytes. Fasting serum leptin concentrations are closely related to body fat content and are higher in obese than in normal-weight individuals. Leptin may contribute to body weight regulation. Overproduction of leptin in certain pathologic conditions such as acquired immunodeficiency syndrome (AIDS) might in principle contribute to the low body fat content associated with body wasting. We measured fasting serum leptin levels by radioimmunoassay in individuals infected with the human immunodeficiency virus (HIV) and in a group of healthy lean men to determine whether HIV infection increases leptin levels. Thirteen HIV-infected men aged 26 to 50 years with a body mass index (BMI) of 15 to 26 kg/m2 and 4 to 24 kg body fat (7% to 29% body fat) had serum leptin levels (3.4 +/- 1.6 ng/mL) that were not elevated compared with the levels in 17 healthy men (4.0 +/- 1.4 ng/mL) matched for age (23 to 47 years), BMI (18 to 26 kg/m2), and body fat (5 to 21 kg; 9% to 28%). In both groups of men, serum leptin concentrations were correlated with percent body fat and body fat content (P < .001), and these relationships were not different between the two groups. In both groups, leptin concentrations were not correlated with lean body mass (P > or = .24). Energy intake in the HIV-infected men, assessed from 3-day intake records, was within the normal range. These findings extend the hypothesis that circulating leptin concentrations directly reflect adipose tissue mass, even in HIV-infected men with low body fat content. These findings do not support the hypothesis that HIV infection is associated with high circulating leptin concentrations, and suggest that low leptin levels do not stimulate food intake in HIV-infected individuals.
肥胖基因（ob）的产物是蛋白质瘦素，它在脂肪细胞中合成并分泌。空腹血清瘦素浓度与体脂含量密切相关，肥胖者的浓度高于正常体重者。瘦素可能有助于体重调节。在某些病理状况如获得性免疫缺陷综合征（AIDS）中瘦素的过度产生原则上可能导致与身体消瘦相关的低体脂含量。我们通过放射免疫测定法测量了感染人类免疫缺陷病毒（HIV）的个体以及一组健康瘦男性的空腹血清瘦素水平，以确定HIV感染是否会增加瘦素水平。13名年龄在26至50岁之间、体重指数（BMI）为15至26kg/m²且体脂为4至24kg（体脂率7%至29%）的HIV感染男性的血清瘦素水平（3.4±1.6ng/mL）与17名年龄（23至47岁）、BMI（18至26kg/m²）和体脂（5至21kg；体脂率9%至28%）相匹配的健康男性相比并未升高。在两组男性中，血清瘦素浓度均与体脂百分比和体脂含量相关（P<.001），且两组之间的这些关系并无差异。在两组中，瘦素浓度与去脂体重均无相关性（P≥.24）。根据3天的摄入记录评估，HIV感染男性的能量摄入在正常范围内。这些发现扩展了如下假设，即循环瘦素浓度直接反映脂肪组织量，即使在体脂含量低的HIV感染男性中也是如此。这些发现不支持HIV感染与高循环瘦素浓度相关的假设，并表明低瘦素水平不会刺激HIV感染个体的食物摄入。
