Plasma Taurine, Diabetes Genetic Predisposition, and Changes of Insulin Sensitivity in Response to Weight-Loss Diets

CONTEXT: Taurine metabolism disturbance is closely linked to obesity, insulin resistance, and diabetes. Previous evidence suggested that the preventative effects of taurine on diabetes might be through regulating the expression levels of diabetes-related genes. OBJECTIVE: We estimated whether blood taurine levels modified the overall genetic susceptibility to diabetes on improvement of insulin sensitivity in a randomized dietary trial. DESIGN AND SETTING: We genotyped 31 diabetes-associated variants to calculate a genetic risk score (GRS) and measured plasma taurine levels and glycemic traits among participants from the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) trial. PARTICIPANTS: Seven-hundred eleven overweight or obese participants (age 30-70 y; 60% females) had genetic variants genotyped and blood taurine levels measured. INTERVENTION: Participants went on 2-year weight-loss diets, which were different in macronutrient composition. MAIN OUTCOME MEASURE: Improvements in glycemic traits were measured. RESULTS: We found that baseline taurine levels significantly modified the effects of diabetes GRS on changes in fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) during the 2-year diet intervention (P-interaction = .04, .01, .002, respectively), regardless of weight loss. High baseline taurine levels were associated with a less reduction in both glucose and HOMA-IR among the participants with the lowest tertile of diabetes GRS (both P = .02), and with a greater reduction in both insulin and HOMA-IR among those with the highest tertile of diabetes GRS (both P = .04). CONCLUSIONS: Our data suggest that blood taurine levels might differentially modulate the effects of diabetes-related genes on improvement of insulin sensitivity among overweight/obese patients on weight-loss diets.