Abstract P429: Coffee Intake is Associated With Enhanced Insulin Sensitivity, Lower Post-Load Glucose Responses, and Lower Truncal Adiposity

Higher coffee consumption has been associated with lower type 2 diabetes (T2D) risk, but the underlying mechanisms remain unclear. We tested the hypothesis that coffee intake is associated with improved glycemia insulin sensitivity, and reduced adiposity. We leveraged data in the VITamin D and OmegA-3 Trial (VITAL), a completed placebo-controlled 5-year trial including 25871 participants. Coffee intake was assessed by a diet questionnaire at baseline and year 2. In the VITAL clinical subcohort (n= 1054), glucose metabolism and insulin resistance were assessed by a 2-hr oral glucose tolerance test, body composition was measured by the dual X-ray absorptiometry, at baseline and year 2. We analyzed the association of coffee intake with glycemic traits and body composition, leveraging repeated assessments using multivariable-adjusted linear mixed models. Secondarily, we tested associations between coffee intake and T2D risk, in 22327 initially T2D-free individuals (482 cases in 5 years of follow-up) using multivariable-adjusted Cox regression. While coffee intake was not associated with fasting glucose or insulin levels, it was significantly associated with lower levels of 2-hr post-load glucose (SD difference per cup increment β = -0.062, P = 0.04) and insulin (β = -0.064, P = 0.02), and a higher metabolic clearance rate of glucose (β= 0.057, P = 0.007) and insulin sensitivity index (β= 0.059, P = 0.02). The associations were consistent for caffeinated and decaffeinated coffee. Further, caffeinated coffee intake was associated with higher body weight (β= 0.018, P = 0.02), but total coffee intake was associated with a lower truncal to limb fat ratio before and after adjusting for BMI (β= -0.057, P = 0.03). We did not observe evidence of association with incident T2D (HR =0.63; 95% CI 0.15-2.50). Higher coffee intake was associated with improved post-load glucose metabolism and insulin sensitivity, and lower truncal adiposity. The figure displays result estimates of linear mixed models. Asterisks represent associations P < 0.05.