Department of Epidemiology, Center for Metabolic Disease Prevention, University of California, Los Angeles, USA.
Diabetes. 2011 Jan;60(1):269-75. doi: 10.2337/db10-1193. Epub 2010 Oct 28.
Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk.
We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw.
Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG.
Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.
咖啡的摄入与 2 型糖尿病风险呈负相关，但其中的机制尚不清楚。我们旨在研究性激素和性激素结合球蛋白（SHBG）的血浆水平是否可能解释咖啡摄入与 2 型糖尿病风险之间的反比关系。
我们进行了一项病例对照研究，嵌套在前瞻性妇女健康研究（WHS）中。在中位随访 10 年期间，359 名新诊断为 2 型糖尿病的绝经后妇女按年龄、种族、随访时间和采血时间与 359 名对照者相匹配。
含咖啡因的咖啡与 SHBG 呈正相关，但与性激素无关。每天饮用≥4 杯含咖啡因咖啡的女性 SHBG 的多变量调整后几何平均水平为 26.6 nmol/L，而不饮用咖啡的女性为 23.0 nmol/L（趋势 P = 0.01）。相比之下，脱咖啡因咖啡和茶均与 SHBG 或性激素无关。与不饮用咖啡的女性相比，每天饮用≥4 杯含咖啡因咖啡的女性 2 型糖尿病的多变量调整后比值比（OR）为 0.47（95%CI 0.23-0.94；趋势 P = 0.047）。进一步调整 SHBG 后，该关联基本减弱（OR 0.71[95%CI 0.31-1.61]；趋势 P = 0.47）。此外，SHBG 基因 rs6259 次要等位基因携带者和 rs6257 次要等位基因非携带者每天饮用≥2 杯含咖啡因咖啡，其 2 型糖尿病的风险降低，方向与相关 SHBG 一致。
我们的研究结果表明，SHBG 可能解释了绝经后妇女中咖啡摄入与 2 型糖尿病风险之间的反比关系。
