Abstract: Objective To analyze the differences in body composition among school-age children with different genders, weight status or obesity types, and to explore the influence of weight status or obesity types on muscle to fat ratio (MFR) and fat mass percentage (FMP). Methods A total of 440 seven-year-old children from Laizhou Wan Birth Cohort were followed up from 2019 to 2020.Twelve kinds of body composition indexes related to the total body composition, fat free mass and fat mass were measured and calculated by human component analyzer.Weight status was divided into three types based on body mass index (BMI).BMI and waist-to-height ratio were used to divide the participants into four obesity types.Then the correlations of weight status and obesity type with body composition were analyzed. Results No significant gender difference in MFR and FMP was found (t=1.16, 0.39, P>0.05).MFR showed a decreased trend among the normal, overweight and obesity groups, and it also decreased in non-obesity, abdominal obesity, general obesity and compound obesity (F=141.65, 63.96, P<0.05).But other body composition indexes increased gradually among groups (P<0.05).The results of multiple linear regression showed that MFR was 3.28 (95%CI:-3.69 - -2.87,P<0.001) lower and FMP was 17.25% (95%CI:16.07 - 18.43,P<0.001) higher in the obese group than that in the normal group.MFR was 3.18 (95%CI:-3.65 - -2.71, P<0.001) lower and FMP was 17.55% (95%CI:16.15 - 18.95, P<0.001) higher in the compound obesity group than that in the non-obesity group. Conclusions The weight gain of obese children is mainly attributed to the increase of body fat.The imbalance of muscle and fat in children with compound obesity suggests that the prevention and control of compound obesity in childhood has important public health significance to reduce its health risk.

Key words: body composition, muscle to fat ratio, fat mass percentage, compound obesity, school-age children

摘要： 目的 分析不同性别、体重状态、肥胖类型学龄儿童的体成分差异,探讨体重状态和肥胖类型对瘦体重与脂肪质量比值(MFR)、体脂百分比(FMP)的影响。 方法 2019-2020年随访山东莱州湾出生队列440名7岁儿童,用体成分仪测量并计算得到总体成分、去脂体重和体脂肪相关的12种体成分指标。依据BMI分为3种体重状态,依据体重指数(BMI)及腰围身高比分为4种肥胖类型,分析其与体成分的关系。 结果 体成分性别差异分析表明,男女生的MFR、FMP差异无统计学意义(t=1.16、0.39,P＞0.05)。MFR在正常、超重、肥胖组间递减,在非肥胖、腹型肥胖、一般性肥胖、复合型肥胖组间也递减(F=141.65、63.96,P＜0.05),而其他体成分指标在各组间呈递增趋势(P＜0.05)。多重线性回归表明肥胖组比正常组儿童的MFR低3.28(95%CI:-3.69~-2.87,P<0.001),FMP高17.25%(95%CI:16.07~18.43,P<0.001);复合型肥胖组比非肥胖组儿童的MFR低3.18(95%CI:-3.65~-2.71,P<0.001),FMP高17.55%(95%CI:16.15~18.95,P<0.001)。 结论 肥胖儿童的增重主要归于体脂肪的增加,复合型肥胖儿童的肌肉和脂肪平衡失调,提示在儿童期防控复合型肥胖对降低其健康风险具有重要的公共卫生学意义。

关键词: 体成分, 瘦体重与脂肪质量比值, 体脂百分比, 复合型肥胖, 学龄儿童