Diabetes mellitus is associated with low exercise capacity and impaired peripheral vasodilation in patients with heart failure − a propensity score-matched study

Diabetes mellitus (DM) and heart failure (HF) share vascular, skeletal and metabolic abnormalities that can reduce exercise capacity. We investigated whether exercise capacity differ in patients with type 2 DM compared to those without DM with HF of similar severity. The Studies Investigating Co-morbidities Aggravating HF (SICA-HF) prospectively enrolled 615 patients with chronic HF, 259 (42.1 %) of whom had DM. We assembled a propensity score-matched cohort of 231 pairs of patients with HF with or without DM who were balanced on age, sex and variables reflecting HF severity. Patients with DM had lower median peak VO 2 (15.7 [13.0–19.1] vs. 17.3 [14.1–21.0] ml/min/kg; p = 0.005). Forearm blood flow reserve (per 1 ml/min/100 ml increase) was associated with lower exercise capacity (peak VO2 ≤ 16.6 ml/min/kg) in patients with DM (OR, 0.92; 95 % CI, (0.85–0.98; p = 0.014), but not in those without DM (OR, 0.98; 95 % CI, 0.93–1.02). A similar heterogeneity was also observed for HDL cholesterol. Diabetes is associated with a reduced exercise capacity in patients with HF. Most predictors of lower exercise capacity in HF are similar regardless of DM except impaired vascular function and lower HDL cholesterol which predict lower exercise capacity only in those with DM.