Baer Heather J, Colditz Graham A, Willett Walter C, Dorgan Joanne F
Channing Laboratory, 181 Longwood Avenue, Boston, MA 02115, USA.
Cancer Epidemiol Biomarkers Prev. 2007 Sep;16(9):1880-8. doi: 10.1158/1055-9965.EPI-07-0313.
Greater body fatness during childhood is associated with reduced risk of premenopausal breast cancer, but few studies have addressed the relation of adiposity with sex hormones in girls. We prospectively examined associations between adiposity and circulating levels of sex hormones and sex hormone-binding globulin (SHBG) among 286 girls in the Dietary Intervention Study in Children. Participants were 8 to 10 years old at baseline and were followed for an average of 7 years. Anthropometric measurements were taken at baseline and at subsequent annual visits, and blood samples were collected every 2 years. Concentrations of dehydroepiandrosterone sulfate (DHEAS) during follow-up were higher among girls with greater body mass index (BMI) at baseline. The mean for the lowest BMI quartile was 63.0 microg/dL compared with 78.8 microg/dL for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with a 4.3% increase (95% confidence interval, 1.6-7.0%) in DHEAS levels during follow-up (P(trend) = 0.002). Concentrations of SHBG during follow-up were lower among girls with greater BMI at baseline. The mean for the lowest BMI quartile was 94.8 nmol compared with 57.5 nmol for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with an 8.8% decrease (95% confidence interval, 7.0-10.6%) in SHBG levels during follow-up (P(trend) < 0.0001). Estrogen and progesterone concentrations were similar across BMI quartiles. These findings suggest that adiposity may alter DHEAS and SHBG levels in girls. Whether and how these differences affect breast development and carcinogenesis requires further research.
儿童期较高的体脂与绝经前乳腺癌风险降低相关，但很少有研究探讨女孩肥胖与性激素之间的关系。我们前瞻性地研究了儿童饮食干预研究中286名女孩的肥胖与性激素及性激素结合球蛋白（SHBG）循环水平之间的关联。参与者在基线时年龄为8至10岁，平均随访7年。在基线和随后的年度随访中进行人体测量，并每2年采集一次血样。随访期间，基线时体重指数（BMI）较高的女孩硫酸脱氢表雄酮（DHEAS）浓度更高。BMI最低四分位数组的平均值为63.0μg/dL，而最高四分位数组为78.8μg/dL，基线BMI每增加1kg/m²与随访期间DHEAS水平增加4.3%（95%置信区间，1.6 - 7.0%）相关（P趋势 = 0.002）。随访期间，基线BMI较高的女孩SHBG浓度较低。BMI最低四分位数组的平均值为94.8nmol，而最高四分位数组为57.5nmol，基线BMI每增加1kg/m²与随访期间SHBG水平降低8.8%（95%置信区间，7.0 - 10.6%）相关（P趋势 < 0.0001）。雌激素和孕酮浓度在各BMI四分位数组中相似。这些发现表明，肥胖可能会改变女孩的DHEAS和SHBG水平。这些差异是否以及如何影响乳房发育和致癌作用需要进一步研究。
