肥胖男性青少年性发育特点及其性激素水平分析

目的:探讨肥胖男性青少年性发育特点并对性激素水平进行分析。方法:选择自2010年1月至2012年6月期间到我院泌尿外科因小睾丸、小阴茎就诊的肥胖男性青少年156例为观察组,对照组选择社区健康青少年男性50例,测算两组对象的体重指数(BMI)、阴茎自然长度、睾丸容积并询问有无遗精及首次遗精年龄,采用放射免疫分析法测定血清黄体生成素(LH)、卵泡刺激激素(FSH)、催乳素(PRL)、总睾酮(TT)、游离睾酮(FT)、孕激素(P)和雌二醇(E2)水平,并计算TT/E2、睾酮分泌指数(TSI)。结果:①观察组BMI[(27.1±2.2)kg/m2]显著高于对照组[(20.4±1.6)kg/m2](P<0.05),阴茎自然长度[(5.6±1.7)cm]及睾丸平均容积[(7.6±2.3)cm3]显著小于对照组(P<0.05);两组青少年首次发生遗精年龄未现显著性差异(P>0.05),但观察组遗精发生率较对照组有极显著性下降(χ2=17.335,P<0.05)。②观察组血清LH、FSH、PRL、TT、FT、E2、P分别为(7.82±2.14)mIU/ml、(7.71±1.83)mIU/ml、(8.91±3.52)ng/ml、(0.73±0.20)ng/ml、(5.09±2.60)pg/ml、(48.57±8.34)pg/ml、(1.25±0.58)ng/ml,对照组分别为(5.39±1.76)mIU/ml、(6.82±2.01)mIU/ml、(8.26±2.97)ng/ml、(1.47±0.41)ng/ml、(11.28±4.72)pg/ml、(8.61±4.08)pg/ml、(0.64±0.19)ng/ml,其中观察组LH、E2、P显著高于对照组(P<0.05,P<0.01,P<0.05),TT、FT显著低于对照组(P均<0.01)。观察组TT/E2值(0.015±0.004)较对照组(0.173±0.037)显著降低(P<0.01);观察组TSI为(0.098±0.026),显著低于对照组(0.272±0.084,P<0.01)。③相关分析表明,BMI与PRL、E2呈显著正相关,与TT、FT、TT/E2及TSI呈显著负相关(P<0.05);阴茎自然长度与TT、FT、TT/E2及TSI呈显著正相关,与E2呈显著负相关(P<0.05);睾丸平均容积与LH、PRL、E2呈负相关,与TT、FT、TT/E2、TSI呈正相关(P<0.05)。结论:肥胖男性青少年存在性发育不良及性激素水平改变,肥胖及脂肪积聚导致E2增高、TT及FT下降、TT/E2、TSI下降尤为明显并与性发育存在显著相关性,提示男性青少年体内的脂肪含量对其生殖系统发育具有重要影响。

Sexual development characteristics and sex hormone levels in obese male adolescents

Objective: To investigate the characteristics of sexual development and sex hormone levels in obese male adolescents.Methods: We included 156 obese male adolescents with micropenis and microorchidia in an observation group and 50 healthy ones in a control group.We measured the body mass index(BMI),penile natural length and testicular volume,investigated the incidence of spermatorrhea and the age of the first spermatorrhea,detected the levels of serum luteinizing hormone(LH),follicle stimulating hormone(FSH),prolactin(PRL),total testosterone(TT),free testosterone(FT),progesterone(P) and estradiol(E2) using radioimmunoassay,and calculated TT/E2 and testosterone secretion index(TSI).Results: Compared with the healthy controls,the obese adolescents showed significantly higher BMI([20.4 ± 1.6] vs [27.1 ± 2.2] kg/m2,P <0.05),but shorter penile natural length([6.7 ± 2.1] vs [5.6 ± 1.7] cm,P <0.05) and lower testis volume([9.9 ± 3.1] vs [7.6 ± 2.3] cm3,P <0.05).The incidence of spermatorrhea was significantly decreased in the observation group in comparison with that of the control(χ2 = 17.335,P < 0.05),but there was no significant difference in the age of the first spermatorrhea between the two groups(P> 0.05).The levels of LH,E2 and P were remarkably higher in the observation group than in the control([7.82 ± 2.14] vs [5.39 ± 1.76] mIU/ml,P < 0.05;[48.57 ± 8.34] vs [8.61 ± 4.08] pg/ml,P < 0.01;and [1.25 ± 0.58] vs [0.64 ± 0.19] ng/ml,P < 0.05),while TT and FT were markedly lower in the former than in the latter([0.73 ± 0.20] vs [1.47 ± 0.41] ng/ml,P < 0.01 and [5.09 ± 2.60] vs [11.28 ± 4.72] pg/ml,P < 0.01),and so were the TT/E2 ratio and TSI(0.015 ± 0.004 vs 0.173 ± 0.037 and 0.098 ± 0.026 vs 0.272 ± 0.084,P < 0.01).BMI was correlated positively to PRL and E2,but negatively to TT,FT,TT/E2 and TSI(P < 0.05);the penile natural length positively to TT,FT,TT/E2 and TSI,but negatively to E2(P < 0.05);and the mean testis volume positively to TT,FT,TT/E2 and TSI,but negatively to LH,PRL and E2(P < 0.05).Conclusion: Testis dysplasia and alteration of sex hormone levels exist in obese male adolescents.Obesity and fat accumulation lead to increased E2 and decreased TT and FT,particularly the reduction of TT/E2 and TSI,which suggest that the body fat content has an important influence on the development of the male reproductive system.