Department of Diabetes Research, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan.
Cardiovasc Diabetol. 2012 Oct 16;11:130. doi: 10.1186/1475-2840-11-130.
Sex hormone-binding globulin (SHBG) levels and sex hormones have been implicated in the pathogenesis of type 2 diabetes and cardiovascular diseases. As fatty liver has been suggested to be a major determinant of SHBG levels, we examined whether the associations of SHBG and testosterone with diabetes were independent of fatty liver.
We conducted a case-control study that included 300 diabetes cases (215 men and 85 women) and 300 matched controls from the Saku cohort study. Diabetes was defined by either fasting plasma glucose levels ≥126 mg/dL, 2-h post-load glucose levels ≥200 mg/dL after a 75 g oral glucose tolerance test, or diabetes diagnosed by physicians. We fitted conditional logistic regression models to examine the associations between SHBG and total testosterone levels with diabetes by sex. To evaluate the impact of fatty liver, we used the fatty liver index (FLI), a validated measure derived from serum triglyceride levels, body mass index (BMI), waist circumference, and γ-glutamyltransferase levels.
After adjusting for age, family history of diabetes, smoking, physical activity, BMI, and FLI, SHBG levels were inversely associated with diabetes among women (odds ratio [OR] comparing the highest with the lowest quartiles, 0.13 [95% confidence interval {CI}, 0.02-0.96]), but not among men. Similar patterns were observed in a subgroup analysis restricted to postmenopausal women"(OR, 0.12 [95% CI, 0.01-1.17]). In contrast, testosterone levels were inversely associated with diabetes among men (OR, 0.45 [95% CI, 0.23-0.89]), but not among women.
Our findings suggest that SHBG in women and testosterone in men may be inversely associated with diabetes.
性激素结合球蛋白 (SHBG) 水平和性激素与 2 型糖尿病和心血管疾病的发病机制有关。由于脂肪肝被认为是 SHBG 水平的主要决定因素，我们研究了 SHBG 和睾酮与糖尿病的关联是否独立于脂肪肝。
我们进行了一项病例对照研究，纳入了来自 Saku 队列研究的 300 例糖尿病患者（215 名男性和 85 名女性）和 300 名匹配的对照。糖尿病的定义为空腹血糖水平≥126mg/dL、口服葡萄糖耐量试验后 2 小时血糖水平≥200mg/dL，或由医生诊断为糖尿病。我们拟合了条件逻辑回归模型，按性别检验 SHBG 和总睾酮水平与糖尿病的关联。为了评估脂肪肝的影响，我们使用了脂肪肝指数（FLI），这是一种从血清甘油三酯水平、体重指数（BMI）、腰围和γ-谷氨酰转移酶水平推导出来的经过验证的指标。
在校正年龄、糖尿病家族史、吸烟、身体活动、BMI 和 FLI 后，SHBG 水平与女性的糖尿病呈负相关（最高四分位数与最低四分位数的比值，0.13[95%可信区间，0.02-0.96]），但在男性中没有。在仅包括绝经后女性的亚组分析中观察到了类似的模式（比值比，0.12[95%可信区间，0.01-1.17]）。相反，睾酮水平与男性的糖尿病呈负相关（比值比，0.45[95%可信区间，0.23-0.89]），但在女性中没有。
我们的研究结果表明，女性的 SHBG 和男性的睾酮可能与糖尿病呈负相关。
