Aims: To examine whether increasing fasting plasma glucose (FPG) levels were associated with worsening left ventricular (LV) diastolic function, independently of LVmass index (LVMI) in elderly, otherwise healthy subjects. Methods and results: We tested cross-sectional associations between echocardiographically determined averaged E/é ratio/diastolic function, LVMI, cardiovascular risk factors, and FPG categorized as normal (NFG), impaired (IFG), and new-onset diabetes mellitus (DM), in 483men and 208 women aged 56-79 years without overt cardiovascular disease, who received no cardiovascular, anti-diabetic, or lipid-lowering drugs and had a preserved LV ejection fraction >50%. Median E/é was significantly higher among subjects with diabetes than those without (8 vs. 7; p=0.03), aswas the prevalence of grade 2 or 3 diastolic dysfunction (25% vs. 16%; p=0.02). E/é and diastolic func tion were significantly associated with LVMI (p≤ 0.002), but not FPG category, on multivariable analysis. However, interaction analyses revealed that increasing LVMI was primarily associated with worsening diastolic function (higher E/é) in subjects with FPG > 6 mmol/L (β = 0.005 for IFG and DM vs. 0.001 for NFG; p = 0.02), whereas increasing systolic blood pressure was primarily associated with worsening diastolic function (higher E/é) in subjects with FPG ≤ 6.9 mmol/L (β= 0.005 for NFG and 0.003 for IFG vs. -0.001 for DM; p = 0.001). Conclusion: Diastolic dysfunctionwas significantly more prevalent among patients with DM than thosewithout. The importance of LVMI increased, but the importance of systolic blood pressure decreased with higher FPG category.