Snehalatha C, Ramachandran A, Satyavani K, Sivasankari S, Vijay V
Diabetes Research Centre, 4 Main Road, Royapuram, Madras, India.
J Assoc Physicians India. 1999 Dec;47(12):1164-7.
Leptin is a hormone probably having regulatory function on energy intake and metabolic activities in humans. The study was done: (a) To determine the relation of leptin with the body fat% in Indians, (b) To see whether the differences in body fat accounted for the gender differences in the concentration of leptin and (c) to look for the effect of diabetes on the levels of leptin.
Glucose tolerance was determined by oral glucose tolerance test (GTT) in 87 subjects with no known history of diabetes. Leptin was estimated by radio immuno assay. Age, height, weight, waist and hip circumferences were noted. Body mass index (BMI, weight kg/height m2) and waist:hip ratio (WHR) were calculated. The body fat % was estimated by bioelectrical impedance analysis.
Leptin correlated with log fat % and BMI, body weight and waist circumference in different categories of glucose tolerance (Pearson's correlation test). Leptin values were higher in women than in men even after correcting for the body fat % indicating that the gender dimorphism was not explained by the higher fat % in women. The geometric mean of leptin concentration in men was 3.6 ng/ml and in women 10.9 ng/ml (P < 0.0001). Leptin level were not influenced by the status of glucose tolerance. Gender showed a significant effect on leptin concentration (F = 11.0, df = 1.39, P = 0.002) after adjusting for the effect of covariates i.e. percentage of fat (log), BMI, age, WHR and 2 h plasma glucose by ANCOVA. None of the covariates except BMI (P < 0.0001) showed significant correlation with leptin. The total variance explained was 68.4%.
We conclude that (1) Plasma leptin is strongly correlated to the body fat content (2) the gender dimorphism of leptin is not explained by the differences in fat percentage and (3) hyperglycemia does not influence plasma leptin levels.
瘦素是一种可能对人体能量摄入和代谢活动具有调节功能的激素。开展本研究旨在：(a) 确定印度人群中瘦素与体脂百分比的关系；(b) 探究体脂差异是否可解释瘦素浓度的性别差异；(c) 研究糖尿病对瘦素水平的影响。
对87名无糖尿病病史的受试者进行口服葡萄糖耐量试验（GTT）以测定葡萄糖耐量。采用放射免疫分析法测定瘦素水平。记录年龄、身高、体重、腰围和臀围。计算体重指数（BMI，体重kg/身高m²）和腰臀比（WHR）。通过生物电阻抗分析估算体脂百分比。
在不同葡萄糖耐量类别中，瘦素与对数体脂百分比、BMI、体重和腰围相关（Pearson相关检验）。即使校正体脂百分比后，女性的瘦素值仍高于男性，这表明女性较高的体脂百分比并不能解释瘦素的性别二态性。男性瘦素浓度的几何平均值为3.6 ng/ml，女性为10.9 ng/ml（P < 0.0001）。瘦素水平不受葡萄糖耐量状态的影响。通过协方差分析（ANCOVA）校正协变量（即脂肪百分比（对数）、BMI、年龄、WHR和2小时血浆葡萄糖）的影响后，性别对瘦素浓度有显著影响（F = 11.0，df = 1.39，P = 0.002）。除BMI外（P < 0.0001），其他协变量与瘦素均无显著相关性。总变异解释率为68.4%。
我们得出以下结论：(1) 血浆瘦素与体脂含量密切相关；(2) 瘦素的性别二态性不能用脂肪百分比差异来解释；(3) 高血糖不影响血浆瘦素水平。
