RESUMO
PURPOSE: Hyperglycemia is affected by lifestyle and genetic factors. We investigated if dietary patterns associate with glycemia in individuals with high or low genetic risk for type 2 diabetes (T2D). METHODS: Men (n = 1577, 51-81 years) without T2D from the Metabolic Syndrome in Men (METSIM) cohort filled a food-frequency questionnaire and participated in a 2-hour oral glucose tolerance test. Polygenetic risk score (PRS) including 76 genetic variants was used to stratify participants into low or high T2D risk groups. We established two data-driven dietary patterns, termed healthy and unhealthy, and investigated their association with plasma glucose concentrations and hyperglycemia risk. RESULTS: Healthy dietary pattern was associated with lower fasting and 2-hour plasma glucose, glucose area under the curve, and better insulin sensitivity (Matsuda insulin sensitivity index) and insulin secretion (disposition index) in unadjusted and adjusted models, whereas the unhealthy pattern was not. No interaction was observed between the patterns and PRS on glycemic measures. Healthy dietary pattern was negatively associated with the risk for hyperglycemia in an adjusted model (OR 0.69, 95% CI 0.51-0.95, in the highest tertile), whereas unhealthy pattern was not (OR 1.08, 95% CI 0.79-1.47, in the highest tertile). No interaction was found between diet and PRS on the risk for hyperglycemia (p = 0.69 for healthy diet, p = 0.54 for unhealthy diet). CONCLUSION: Our findings suggest that healthy diet is associated with lower glucose concentrations and lower risk for hyperglycemia in men with no interaction with the genetic risk.
RESUMO
CONTEXT: Lifestyle intervention prevents or delays type 2 diabetes (T2D) in subjects at a high risk of T2D. However, it is not known whether genetic variants modify the effect on incident T2D during lifestyle intervention. OBJECTIVE: To investigate whether a low or high genetic risk has effects on incident T2D in a group-based lifestyle intervention study. METHODS: The T2D-GENE trial involved 973 men from the Metabolic Syndrome in Men (METSIM) cohort, aged 50-75 years, body mass index ≥25 kg/m2, fasting plasma glucose 5.6-6.9 mmol/l, and HbA1c <48 mmol/mol and either a low or high genetic risk score for T2D. There were two intervention groups, a low (n=315) and high genetic risk for T2D (n=313). They were provided with a 3-year group-based intervention with access to a web portal focused on healthy diet and physical activity. There were also corresponding population-based control groups at low (n=196), and high genetic risk for T2D (n=149) who had two laboratory visits (0 and 3 years) and general health advice as a part of their METSIM cohort protocol. The primary outcome was incident T2D, and a secondary outcome glycemia. RESULTS: The intervention significantly lowered the risk of T2D among the participants with a high genetic risk for T2D (HR 0.30, 95% CI 0.16-0.56, p<0.001) whereas in the low genetic risk group the effect was not significant (HR 0.69, 95% CI 0.36-1.32, p=0.262). The intervention effect was not significantly different between the high and low genetic risk groups (p=0.135). The intervention significantly ameliorated the worsening of glycemia and decreased weight both in the low and high genetic risk groups. CONCLUSIONS: Our results showed that individuals with a high genetic risk for T2D benefited from a low-cost group-based intervention focusing on healthy diet and physical activity. Therefore, all individuals at risk of T2D should be encouraged to make lifestyle changes regardless of genetic risk.