Metformin is associated with improved left ventricular diastolic function measured by tissue Doppler imaging in patients with diabetes

Objective: To examine the association between selected glucose-lowering medications and left ventricular (LV) diastolic function in patients with diabetes. Design: Retrospective cohort study (years 2005-2008). Methods: Echocardiograms of 242 patients with diabetes undergoing coronary angiography were analyzed. All patients had an LV ejection fraction (LVEF) ≥20% and were without atrial fibrillation, bundle branch block, valvular disease, or cardiac pacemaker. Patients were grouped according to the use of metformin (n = 56), sulfonylureas (n = 43), insulin (n = 61), and combination treatment (n = 82). Results: Mean age (66 ± 10 years) and mean LVEF (45 ± 11%) were similar across the groups. Mean isovolumic relaxation time (IVRT) was 66 ± 31, 79 ± 42, 69 ± 23, and 66 ± 29 ms in metformin, sulfonylureas, insulin, and combination treatment groups respectively (P = 0.4). Mean early diastolic longitudinal tissue velocity (e′) was 5.3 ± 1.6, 4.6 ± 1.6, 5.3 ± 1.8, and 5.4 ± 1.7 cm/s in metformin, sulfonylureas, insulin, and combination treatment groups (P = 0.04). In adjusted linear regression models, the use of metformin was associated with a shorter IVRT (parameter estimate K9.9 ms, P = 0.049) and higher e′ (parameter estimate +0.52 cm/s, P = 0.03), compared with no use of metformin. The effects of metformin were not altered by concomitant use of sulfonylureas or insulin (P for interactions >0.4). Conclusions: The use of metformin is associated with improved LVrelaxation, as compared with no use of metformin.