Cardiac dysfunction in type II diabetes: a bittersweet, weighty problem, or both?

Melissa Leung, Vincent W. Wong, Ertugrul Durmush, Victoria Phan, Mikey Xie, Dominic Y. Leung

Weight loss in obese patients leads to improved left ventricular (LV) function. It is unclear whether improving glycaemic control has additional benefits to weight loss alone in patients with type 2 diabetes, or if benefits of weight loss are mediated through improving glycaemic control. This case-control study examined the incremental impact of these approaches on LV function. Three groups of age, gender, and baseline HbA1c-matched patients with type 2 diabetes and suboptimal glycaemic control were followed-up for 12 months. Group 1 patients did not improve HbA1c ≥ 1 % (10.9 mmol/mol) or lose weight. Group 2 improved HbA1c ≥ 1 % but did not lose weight. Group 3 improved HbA1c ≥ 1 % (10.9 mmol/mol) and lost weight. All patients underwent transthoracic echocardiogram at baseline and at follow-up. At baseline, three groups were comparable in all clinical and metabolic parameters except Group 3 had highest body mass index. The three groups had similar echocardiographic parameters except Group 3 had the worst LV systolic function [global longitudinal strain (GLS)]. At follow-up, LV ejection fraction and diastolic function improved with a reduction in filling pressures in Group 2 and more so in Group 3. LV filling pressures in Group 1 increased. There was a significant improvement in GLS in Group 2 and more so in Group 3. Despite GLS being the worst in Group 3 at baseline, this was comparable between Groups 2 and 3 at follow-up. In overweight patients with type 2 diabetes, weight loss and improved glycaemic control had additive beneficial effects on improving LV systolic and diastolic function.