Association between parental history of diabetes and type 2 diabetes genetic risk scores in the PPP-Botnia and Framingham Offspring Studies

ObjectiveParental history of diabetes and specific gene variants are risk factors for type 2 diabetes, but the extent to which these factors are associated is unknown.MethodsWe examined the association between parental history of diabetes and a type 2 diabetes genetic risk score (GRS) in two cohort studies from Finland (population-based PPP-Botnia study) and the US (family-based Framingham Offspring Study).ResultsMean (95% CI) GRS increased from 16.8 (16.8–16.9) to 16.9 (16.8–17.1) to 17.1 (16.8–17.4) among PPP-Botnia participants with 0, 1, and 2 parents with diabetes, respectively (ptrend = 0.03). The trend was similar among Framingham Offspring but was not statistically significant (p = 0.07). The meta-analyzed p value for trend from the two studies was 0.005.ConclusionsThe very modest associations reported above suggest that the increased risk of diabetes in offspring of parents with diabetes is largely the result of shared environmental/lifestyle factors and/or hitherto unknown genetic factors.