Wang Youfa
Department of Human Nutrition and Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
Pediatrics. 2002 Nov;110(5):903-10. doi: 10.1542/peds.110.5.903.
Increasing evidence suggests a close association between early sexual maturation (SM) and obesity in girls and female adults. Earlier maturing girls are more likely to be obese than nonearly maturers. However, limited research has been conducted in boys.
To examine the influence of early SM on fatness in boys and compare it with girls, and to test the hypothesis that the associations differ by gender because of the differences in growth and SM patterns in boys and girls.
Cross-sectional study.
One thousand five hundred one girls and 1520 boys (aged 8-14 years) who participated in the Third National Health and Nutrition Examination Survey survey (1988-1994) and had complete anthropometry (weight, height, skinfold thickness) and SM data.
Based on each individual's age and SM status (Tanner stages: genitalia stages for boys and breast stages for girls), the subjects were classified as: 1) early maturers (those who reached a certain Tanner stage earlier than the median age for that stage), and 2) the others (average and later maturers). Overweight was defined as a body mass index (BMI) > or =85th percentile, and obesity > or =95th percentile. Logistic regression analysis was to test how early maturation affected the risks for overweight and obese. Using multiple linear regression models, the associations between fatness (BMI and skinfold thickness) and SM were systematically examined. Covariates including age, ethnicity, residence, family income, energy intake, and physical activity were adjusted.
Early SM was positively associated with overweight and obesity in girls, but the associations were reverse for boys. The prevalence of overweight in early maturers versus the others was 22.6% versus 31.6% in boys and 34.4% versus 23.2% in girls; the figures for obesity were 6.7% versus 14.8% and 15.6% versus 8.1%, respectively. Odd ratios and 95% confidence intervals for obesity were 0.4 (0.2, 0.8) for boys and 2.0 (1.1, 3.5) for girls, and covariates were adjusted. Most significant differences in overweight and obesity among ethnic groups disappeared after controlling for SM. Fatness (BMI and skinfold thickness) was associated with SM stages and with early maturation in boys and girls, but the associations were in opposite directions. Compared with their counterparts, early maturing boys were thinner, whereas early maturing girls were fatter.
Obesity is associated with sexual maturation in both boys and girls, but the association differs. There is positive association in girls, but a negative one in boys. Maturation status should be taken into consideration when assessing child and adolescent obesity.
越来越多的证据表明，女童及成年女性的性早熟（SM）与肥胖之间存在密切关联。性早熟女童比性发育正常的女童更易肥胖。然而，针对男童的相关研究较少。
研究性早熟对男童肥胖的影响，并与女童进行比较，检验以下假设：由于男童和女童生长及性早熟模式不同，二者之间的关联存在性别差异。
横断面研究。
1501名女童和1520名男童（年龄8 - 14岁），他们参与了第三次全国健康和营养检查调查（1988 - 1994年），并拥有完整的人体测量数据（体重、身高、皮褶厚度）和性早熟数据。
根据个体年龄和性早熟状态（坦纳分期：男童为生殖器分期，女童为乳房分期），将研究对象分为：1）性早熟者（达到某一坦纳分期的年龄早于该分期的中位数年龄），2）其他（发育正常及发育较晚者）。超重定义为体重指数（BMI）≥第85百分位数，肥胖定义为BMI≥第95百分位数。采用逻辑回归分析检验性早熟如何影响超重和肥胖风险。使用多元线性回归模型，系统研究肥胖程度（BMI和皮褶厚度）与性早熟之间的关联。对年龄、种族、居住地、家庭收入、能量摄入和身体活动等协变量进行了调整。
性早熟与女童超重和肥胖呈正相关，但与男童的关联相反。性早熟者与其他儿童相比，超重患病率在男童中分别为22.6%和31.6%，在女童中分别为34.4%和23.2%；肥胖患病率分别为6.7%和14.8%，以及15.6%和8.1%。调整协变量后，男童肥胖的比值比及95%置信区间为0.4（0.2，0.8），女童为2.0（1.1，3.5）。控制性早熟因素后，各民族间超重和肥胖的大多数显著差异消失。肥胖程度（BMI和皮褶厚度）与男童和女童的性早熟分期及性早熟均有关联，但方向相反。与发育正常的儿童相比，性早熟男童更瘦，而性早熟女童更胖。
肥胖与男童和女童的性早熟均有关联，但关联有所不同。女童中为正相关，男童中为负相关。在评估儿童和青少年肥胖时应考虑性成熟状态。
