The relationship between functional capacity and left ventricular strain in patients with uncomplicated type 2 diabetes

Objective: We aimed to evaluate the association between functional capacity and left ventricular (LV) mechanics in the patients with uncomplicated type 2 diabetes. Methods: The present cross-sectional study included 80 controls and 70 uncomplicated diabetic patients. These participants underwent laboratory analysis, comprehensive echocardiographic examination and cardiopulmonary exercise testing. Results: Global longitudinal (-21.6 +/- 2.8 vs. -18.4 +/- 2.3%, P < 0.001) and circumferential (-22.0 +/- 2.9 vs. -19.5 +/- 2.6%, P < 0.001) strains were significantly reduced in diabetic participants. The same was found for longitudinal and circumferential endocardial, mid-myocardial and epicardial strains. Peak oxygen uptake (27.0 +/- 4.3 vs. 20.7 +/- 4.0 ml/kg/min, P < 0.001) and oxygen pulse (14.1 +/- 3.0 vs. 11.6 +/- 3.2 ml/beat, P < 0.001) were significantly lower in the diabetic group, while ventilation/carbon dioxide slope was significantly higher in these patients. In the whole study population glycosylated hemoglobin, as well as LV endocardial longitudinal and circumferential strains were independently of other clinical and echocardiographic parameters of LV structure, systolic and diastolic function associated with peak oxygen consumption and oxygen pulse. Conclusion: Our investigation showed that diabetes equally affected all LV myocardial layers. Endocardial LV longitudinal and circumferential strains, as well as glycosylated hemoglobin - main parameter of glucose regulation, were independently associated with functional capacity in the whole study population. These findings indicate that determination of LV strain and functional capacity could detect subclinical target organ damage and prevent development of further complications in uncomplicated diabetes mellitus patients.