Diabetes may Impair Exercise Capacity in Heart Failure Patients, Study Finds

"Most predictors of reduced exercise capacity in heart failure are consistent across patients, regardless of diabetes. However, impaired vascular function and lower HDL cholesterol specifically predict decreased exercise capacity only in individuals with diabetes," the researchers wrote in Diabetes Research and Clinical Practice.

Exercise intolerance is a key feature of heart failure, significantly impacting quality of life and associated with higher mortality. Patients with HF experience greater declines in physical function compared to those with other chronic diseases. Diabetes, prevalent in 45% of HF patients, further reduces exercise capacity due to complex interactions affecting muscle and vascular function. Understanding these mechanisms may aid in developing new therapies for HF.

Against the above background, Miroslava Valentova, Department of Cardiology & Pneumology, University Medical Center Goettingen, and DZHK (German Centre for Cardiovascular Research), partner site Goettingen, Germany, and colleagues examined whether exercise capacity differs in patients with type 2 DM compared to those without DM with HF of similar severity.

For this purpose, the Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF) prospectively enrolled 615 patients with chronic heart failure, of whom 259 (42.1%) had diabetes mellitus. A propensity score-matched cohort was created consisting of 231 pairs of patients with heart failure, balanced for age, sex, and other variables indicating heart failure severity.

The study led to the following findings:

• The analysis revealed that patients with diabetes had a lower median peak VO2 of 15.7 ml/min/kg compared to 17.3 ml/min/kg in those without diabetes.
• Forearm blood flow reserve (per 1 ml/min/100 ml increase) was linked to lower exercise capacity (peak VO2 ≤ 16.6 ml/min/kg) in patients with diabetes (OR, 0.92), but this association was not found in non-diabetic patients (OR, 0.98).
• There was a similar pattern with HDL cholesterol levels.

The study showed that patients with diabetes mellitus and heart failure exhibit lower exercise capacity, as indicated by peak oxygen consumption per kilogram of body mass, compared to those without diabetes of similar age, sex, and HF severity. Additionally, patients with DM had reduced peripheral blood flow reserve, elevated serum creatinine levels, higher HbA1c, lower HDL cholesterol, and a smaller increase in maximum heart rate compared to their non-diabetic counterparts.

Reference:

Valentova, M., Vatic, M., Garfias-Veitl, T., Sandek, A., Bekfani, T., Jankowska, E. A., Cleland, J. G., Clark, A. L., Lainscak, M., Ahmed, A., Jauert, N., Hasenfuss, G., Anker, S. D., Doehner, W., & Von Haehling, S. (2024). Diabetes mellitus is associated with low exercise capacity and impaired peripheral vasodilation in patients with heart failure − a propensity score-matched study. Diabetes Research and Clinical Practice, 111864. https://doi.org/10.1016/j.diabres.2024.111864