上海地区儿童和青少年血清瘦素水平与肥胖度、青春期发育的关系

The relationship between serum leptin concentration and adiposity, pubertal stage in children and adolescents from Shanghai region

目的 研究上海地区儿童和青少年血清瘦素 (leptin)水平与肥胖度、青春期发育的关系。方法 用放射免疫分析法测定 10 4例健康非肥胖男孩和 118例健康非肥胖女孩 (年龄在 4.8岁至 2 0岁之间 )的血清瘦素水平。结果 (1)无论是男孩还是女孩 ,血清瘦素水平均与体重指数 (BMI)呈正相关。在女孩 ,血清瘦素水平与年龄呈正相关 ;而在男孩 ,血清瘦素水平与年龄呈负相关。 (2 )随着年龄的增长 ,青春期发育的开始 ,女孩的血清瘦素水平从Ⅰ期 (Tanner分期 ,下同 )至Ⅴ期逐步上升。男孩的血清瘦素水平则从Ⅰ期的 3 .12ng/ml上升至Ⅱ期的 3 .95ng/ml后即逐步下降 ,在Ⅴ期达最低。 (3)在TannerⅠ期和Ⅱ期 ,男孩与女孩的血清瘦素水平接近。但在Ⅱ期之后 ,两者的性别差异显著 (P <0 .0 0 1) ,在相同的BMI水平 ,男孩的血清瘦素浓度要远低于女孩。 (4 )在以瘦素为因变量 ,BMI、性别、年龄、Tanner分期为自变量的逐步多元回归中 ,BMI仍是影响瘦素浓度最为显著的因素。结论 (1)与成人相似 ,儿童和青少年的血清瘦素水平与BMI密切相关。 (2 )随着青春期发育 ,女孩的血清瘦素水平逐步上升 ,而男孩的血清瘦素水平则在青春期发育开始后先升高后下降 ,提示瘦素在促进两性性发育上可能起一激发作用 。

Objective To investigate the relationship between serum leptin concentration and body fat, pubertal stage in children and adolescents from Shanghai region. Methods Serum leptin concentration was measured by RIA in 222 healthy non obese children and adolescents recruited from Shanghai region (104 boys and 118 girls, age from 4.8 to 20 years). Results (1)Serum leptin level was positively correlated with body mass index (BMI) in both boys and girls, but was positively correleted with age in girls while negatively in boys. (2)With the pubertal development, leptin concentration of the girls increased steadily from Tanner stage Ⅰ to Ⅴ. But in the boys, it started from 3.12 ng/ml at Tanner stage Ⅰ and reached the peak level (3.95 ng/ml) at stage Ⅱ, then declined gradually to the nadir at stage Ⅴ. (3)During the Tanner stage Ⅰ and Ⅱ leptin concentrations were similar in both sexes and after Tanner stage Ⅱ a significant gender based difference of leptin concentrations was found (P<0.001). (4)BMI was found to be the most important one among the factors which affect the leptin levels by multiple stepwise regression analysis taking leptin as the dependent variable, and BMI, sex, age and Tanner stage as the independent variables. Conclusion (1)Similar to adults, serum leptin concentrations in children and adolescents are strongly correlated with BMI. (2)Serum leptin concentration is continuously increasing in girls and increases initially then decreases in boys right after the onset of puberty, which suggests that leptin may play a triggering role in promoting puberty of both sexes and it is also an essential factor in completing puberty and in maintaining reproductive functions for the females.