Contex: Determinants of the variance in glycated hemoglobin (HbA1c) among individuals without type 2 diabetes remain largely unknown. Objective: We investigated the determinants of HbA1c, fasting plasma glucose (FPG) and 2-hour glucose (2hPG) in an oral glucose tolerance test, and the associations of these glycemic markers with insulin sensitivity and insulin secretion in Finnish men without type 2 diabetes. Design and Setting: The cross-sectional population-based METabolic Syndrome In Men (METSIM) Study including 10,197 Finnish men, aged 45-70 years, and randomly selected from the population register of Kuopio, Eastern Finland. Participants: A total of 9,398 men without type 2 diabetes or with newly-diagnosed type 2 diabetes at baseline (mean age, 57±7 years; BMI, 27.0±4.0 kg/m(2), mean ± SD) in the METSIM cohort. Interventions: An oral glucose tolerance test. Main outcome measures: Glycemic and non-glycemic determinants of the variance in HbA1c among participants without type 2 diabetes, and the association of HbA1c with insulin secretion and insulin sensitivity. Results: Age, FPG and hs-CRP were the strongest determinants of HbA1c, explaining 12% of the variance in HbA1c levels in participants without type 2 diabetes. Disposition index (insulin secretion) and the Matsuda ISI (insulin sensitivity) explained only < 2% of the variance in HbA1c in participants without type 2 diabetes. Conclusions: The variance in HbA1c among men without type 2 diabetes was largely determined by non-glycemic factors and only weakly by impaired insulin sensitivity and insulin secretion.