Time-restricted eating (TRE) has been proposed as a non-pharmacological strategy with cardio-metabolic benefits in overweight individuals but little is known about its metabolic impact in type 2 diabetes (T2DM). Thus, we sought to evaluate whether TRE can improve beta-cell function and metabolic status in overweight individuals with early T2DM. In a cross-over randomized trial, 39 participants (25 women, age 56.3 yrs, BMI 32.4 kg/m2, T2DM duration 2.9 yrs, A1c 6.6%) were randomized to either 6-weeks of TRE (20h-fasting/4h-eating) or standard lifestyle, followed by 4-weeks washout before 6-weeks of the other approach to eating. The primary outcome of beta-cell function was assessed by Insulin Secretion-Sensitivity Index-2 (ISSI-2) derived from an oral glucose tolerance test. As compared to standard lifestyle, TRE induced a 14% increase in ISSI-2 (p=0.03) accompanied by 14% reduction of HOMA-IR (p=0.03) (Figure). Fasting glucose did not differ between interventions, but TRE yielded a significant reduction in A1c (-0.32%, p<0.001). These metabolic improvements were likely driven by its effects in reducing body weight by 3.86% (p<0.001) and waist circumference by 3.8 cm (p=0.003).
In conclusion, TRE improved beta-cell function and insulin resistance in overweight patients with early T2DM, likely through its beneficial effects on adiposity.
C.K. Kramer: Research Support; Boehringer-Ingelheim. R. Retnakaran: Research Support; Boehringer-Ingelheim. Consultant; Eli Lilly and Company, Novo Nordisk, Sanofi. B. Zinman: Advisory Panel; Abbott, Eli Lilly and Company, Novo Nordisk.
Canadian Institutes of Health Research (PJT166091)
