Alperet Derrick Johnston, Rebello Salome Antonette, Khoo Eric Yin-Hao, Tay Zoey, Seah Sharna Si-Ying, Tai Bee-Choo, Emady-Azar Shahram, Chou Chieh Jason, Darimont Christian, van Dam Rob M
NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.
Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
Contemp Clin Trials Commun. 2016 Aug 2;4:105-117. doi: 10.1016/j.conctc.2016.06.013. eCollection 2016 Dec 15.
Coffee consumption has been consistently associated with a lower risk of type 2 diabetes mellitus in cohort studies. In addition, coffee components increased insulin sensitivity in animal models. However, data from intervention studies on the effect of coffee consumption on glucose metabolism have been limited by small sample sizes, lack of blinding, short follow-up duration and the use of surrogate indices of insulin sensitivity. We designed the Coffee for Metabolic Health (COMETH) study to evaluate the effect of coffee consumption on insulin sensitivity.
The COMETH study is a double-blind randomized placebo-controlled 24-week trial. Participants were overweight, male and female habitual coffee consumers who were of Chinese, Malay and Asian-Indian ethnicity. We excluded smokers, persons with diabetes, and persons with low insulin resistance (HOMA-IR < 1.30). Participants were randomly assigned to receive daily 4 cups of instant regular coffee or 4 cups of a coffee-like placebo beverage. The hyperinsulinemic euglycemic clamp was performed at baseline and at the end of 24 weeks to determine changes in the bodyweight standardized M-value. Secondary outcomes included changes in fasting glucose and insulin sensitivity mediators such as adiponectin, markers of inflammation, liver function, and oxidative stress.We enrolled 128 participants, 126 (57.1% males; aged 35-67 years) of whom completed baseline assessments.
If improvement in insulin sensitivity in the coffee group is significantly greater than that of the placebo group, this would support the hypothesis that coffee consumption reduced risk of type 2 diabetes through biological pathways involving insulin sensitivity.
ClinicalTrials.gov identifier: NCT01738399. Registered on 28 November 2012. Trial Sponsor: Nestlé Research Center, Lausanne, Switzerland. Trial Site: National University of Singapore.
队列研究一直表明，喝咖啡与2型糖尿病风险降低相关。此外，咖啡成分可提高动物模型的胰岛素敏感性。然而，关于喝咖啡对糖代谢影响的干预研究数据存在样本量小、缺乏盲法、随访时间短以及使用胰岛素敏感性替代指标等局限性。我们设计了代谢健康咖啡（COMETH）研究，以评估喝咖啡对胰岛素敏感性的影响。
COMETH研究是一项为期24周的双盲随机安慰剂对照试验。参与者为超重的、有喝咖啡习惯的男性和女性，包括华裔、马来裔和印度裔亚洲人。我们排除了吸烟者、糖尿病患者以及胰岛素抵抗较低（稳态模型评估的胰岛素抵抗指数[HOMA-IR]<1.30）的人。参与者被随机分配，每天饮用4杯速溶纯咖啡或4杯类似咖啡的安慰剂饮料。在基线和24周结束时进行高胰岛素正常血糖钳夹试验，以确定体重标准化M值的变化。次要结局包括空腹血糖和胰岛素敏感性介质（如脂联素）、炎症标志物、肝功能和氧化应激的变化。我们招募了128名参与者，其中126名（57.1%为男性；年龄35 - 67岁）完成了基线评估。
如果咖啡组胰岛素敏感性的改善显著大于安慰剂组，这将支持以下假设：喝咖啡通过涉及胰岛素敏感性的生物学途径降低2型糖尿病风险。
ClinicalTrials.gov标识符：NCT01738399。于2012年11月28日注册。试验主办方：瑞士洛桑雀巢研究中心。试验地点：新加坡国立大学。
