Objective: To study the association of body fat ratio with precocious puberty in girls. Previous studies have shown that body mass index (BMI) is associated with the girls' age of puberty but have not revealed the association of body fat ratio with age of puberty.
Methods: Based on the consensus on the diagnosis and treatment of central precocious puberty (CPP), 128 children with precocious puberty who were admitted to the hospital from July to August, 2017, were divided into a CPP group with 87 children and a peripheral precocious puberty (PPP) group with 41 children. A total of 51 girls without any puberty development signs were enrolled as the control group. Dual-energy X-ray absorptiometry was used to measure the body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body. The association between body fat ratios and precocious puberty was analyzed with reference to age, BMI, BMI-Z score, bone age, ovarian volume, and hormone levels.
Results: Compared with the control group, the CPP and PPP groups had significantly higher body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body, legs/whole body fat ratio, and (upper limbs+legs)/trunk fat ratio (P<0.05), while there were no significant differences in the above body fat ratios and fat distribution indicators between the CPP and PPP groups (P>0.05). For the girls with precocious puberty, the high body fat ratio group had significantly higher luteinizing hormone (LH) base value, luteinizing hormone releasing hormone (LHRH)-stimulated LH peak value, and LH/follicle-stimulating hormone peak value than the low body fat ratio group (P<0.05). Compared with the control group, both the high body fat ratio and low body fat ratio groups had a significantly higher LH base value (P<0.05).
Conclusions: The increase in body fat may be a factor inducing precocious puberty in girls, but further studies are needed to determine the mechanism.
目的: 既往研究提示体重指数(BMI)与女童发育年龄有关，但是否与女童全身脂肪比率相关尚不清楚。该研究旨在分析全身脂肪比率与性早熟的关联性。
方法: 依据中枢性性早熟诊断与治疗共识将2017年7~8月收治的128例性早熟患儿分为中枢性性早熟组(CPP组，87例)和外周性性早熟组(PPP组，41例)，同时纳入51例未发育女童作为对照组。利用双能X线吸收测量法检测上肢组织、腿部组织、躯干组织、男性区、女性区和全身组织的脂肪比率，结合研究对象的年龄、BMI、BMI-Z值、骨龄、卵巢体积、激素水平等实验室检查结果，综合分析脂肪比率和性早熟的相关性。
结果: 与对照组比较，CPP组和PPP组患儿上肢、腿部、躯干、男性区、女性区和全身组织的体脂率参数以及腿部/全身脂肪比和(上肢+腿部)/躯干脂肪比均显著升高(均P < 0.05)，而上述所有体脂率和脂肪分布指标在CPP组和PPP组间比较差异均无统计学意义(均P > 0.05)。在性早熟女童中，高体脂率组的黄体生成素(LH)基础值及黄体生成素释放激素(LHRH)激发试验的LH峰值、LH/卵泡刺激素峰值均显著高于低体脂率组，差异均有统计学意义(均P < 0.05)。同时高体脂率组和低体脂率组LH基础值相比于对照组均显著升高(均P < 0.05)。
结论: 体脂含量的增加可能是诱发女童性早熟的因素，但具体机制尚有待进一步研究。