儿童血瘦素水平对青春期发育的作用

目的研究血瘦素水平对儿童青春期发育的作用.方法单纯性肥胖和健康学生各300名,调查男生首次遗精和女生月经初潮时间,测定血瘦素、性激素、生长激素和胰岛素水平.结果随年龄增长,瘦素在男生呈低→高→低变化,肥胖组(1.04±0.21)nmol/L→(1.20±0.27)nmol/L→(0.66±0.10)nmol/L,对照组(0.31±0.06)nmol/L→(0.45±0.10)nmol/L→(0.19±0.04)nmol/L;在女生呈增高趋势,肥胖组从(0.89±0.15)nmol/L增至(1.39±0.23)nmol/L,对照组从(0.46±0.08)nmol/L增至(0.88±0.18)nmol/L.各组性激素呈增高趋势.生长激素呈某一年龄突增,且男女不同(男生14～15岁,女生13～14岁).各年龄肥胖组瘦素和胰岛素高于对照组;男生各年龄肥胖组生长激素低于对照组.男女肥胖组血瘦素水平高于对照组,男(0.71±0.17)nmol/L与(0.30±0.04)nmol/L,女(1.11±0.21)nmol/L与(0.70±0.18)nmol/L;其初潮/首次遗精时间提前,男(12.5±1.2)岁与(13.2±1.2)岁,女(11.6±0.8)岁与(12.8±0.9)岁.女生瘦素水平高于男生,其初潮时间早于男生首次遗精时间.肥胖组男生的睾酮与瘦素呈负相关,女生的雌二醇与瘦素呈正相关,男生的生长激素与瘦素呈负相关,女生的生长激素与瘦素呈正相关;对照组女生的胰岛素与瘦素呈正相关.结论瘦素对青春期的启动可能有重要作用,对女性可能比男性更为重要;瘦素与生长激素相关关系的两性差异可能是造成男女生长突增时间不同的原因之一;瘦素与性激素相关关系的两性差异可能是造成男女首次遗精/初潮时间不同的原因之一.

Study on the effects of leptin on puberty development in children

OBJECTIVE: To study the effects of leptin on puberty development in children. METHODS: Three hundred obese and 300 healthy children without taking any medication or having evidence of endocrine or metabolic diseases were studied. Their ages of first spermatorrhea and menarche were surveyed, and blood levels of leptin, sex hormones, growth hormone (GH) and insulin (INS) were measured. RESULTS: With increased of age, blood levels of leptin appeared from low to high and from high to low again in the boys, with (1.04 +/- 0.21) nmol/L to (1.20 +/- 0.27) nmol/L and to (0.66 +/- 0.10) nmol/L in the obese group, and with (0.31 +/- 0.06) nmol/L to (0.45 +/- 0.10) nmol/L and to (0.19 +/- 0.04) nmol/L in the control group. While blood level of leptin appeared an increasing trend in girls, with (0.89 +/- 0.15) nmol/L to (1.39 +/- 0.23) nmol/L in the obese group, and (0.46 +/- 0.08) nmol/L to (0.88 +/- 0.18) nmol/L in the control group. Levels of sex hormones also appeared an increasing trend in the all groups. Levels of GH showed an abrupt increased at certain ages, different in boys from girls (14-15 years of age in boys and 13-14 in girls). In the all ages, serum levels of leptin and INS were higher in the obese group than those in the control group, while the level of GH was lower in the obese group than that in the control group. Serum level of leptin was higher in the obese group of both boys and girls than that in the control group, with (0.71 +/- 0.17) nmol/L and (0.30 +/- 0.04) nmol/L and (1.11 +/- 0.21) nmol/L and (0.70 +/- 0.18) nmol/L, respectively. Ages at first spermatorrhea and menarche were much earlier in the obese children than those in the controls, with (12.5 +/- 1.2) and (13.2 +/- 1.2) years of age in boys and (11.6 +/- 0.8) and (12.8 +/- 0.9) in the girls, respectively. Blood levels of leptin was higher in the girls than that in the boys. Age at menarche and earlier in the girls than that of first spermatorrhea in the boys. Blood level of testosterone correlated inversely with that of leptin in boys, while that of estradiol correlated with that of leptin in girls. Level of GH correlated inversely with that of leptin in boys and correlated with that in girls. Level of INS correlated with that of leptin in the control girls. CONCLUSIONS: Leptin might have an effect on initiation of puberty in children, possibly with more importance in girls than in boys. The gender difference in the degree of correlations between levels of leptin and GH may cause their difference in the ages at sudden growth in boys and girls. The gender difference in the degree of correlation between levels of leptin and sex hormone may cause their difference in the ages at first spermatorrhea and menarche in both boys and girls.