Genetic and baseline metabolic factors for incident diabetes and HbA1cat follow-up: the healthy twin study

Background We investigated baseline anthropometric/metabolic traits predicting incident diabetes, genetic/environmental relationships between these traits and HbA1c at follow-up and the contribution of genetics, covariates and environments to variance in HbA1c at follow-up and incident diabetes. Methods Nondiabetic twins (n = 869) and their family members (n = 949) were followed over 3.7 ± 1.4 years (44.3 ± 12.8 years of age); baseline anthropometric/metabolic traits were measured. Fasting plasma glucose and HbA1c were measured at follow-up. Incident diabetes was defined as HbA1c ≥6.5% or fasting plasma glucose ≥7 mmol/L. Results Age-adjusted incident diabetes was 4.9% in men and 4.1% in women. Odd ratio for incident diabetes was 2.34–2.40, 1.25-1.28, 1.22–1.27 and 1.89 per standard deviation of baseline fasting plasma glucose, white blood cell (WBC), triglycerides and waist circumference, respectively, in multivariate generalized estimating equation models (p