Poor cardiorespiratory fitness a potential modifiable risk factor for HF in diabetes

Intensive lifestyle intervention (ILI) seems to be of little benefit in terms of lowering heart failure (HF) risk in type 2 diabetes (T2D) patients with overweight or obesity when compared with standard diabetes support and education (DSE), although weight loss and sustained improvements in cardiorespiratory fitness (CRF) may be protective, according to a study.

The analysis included 5,109 trial participants from the Look AHEAD (Action for Health in Diabetes) trial without HF. Of these, 257 developed HF over a median follow-up of 12.4 years (event rate, 4.42 per 1,000 person years [PY]), of which 50.2 percent had preserved ejection fraction (pEF; event rate, 2,23 per 1,000 PY), 40.5 percent had reduced ejection fraction (rEF; event rate, 1.79 per 1,000 PY), and 9.3 percent had missing left ventricular ejection fraction (LVEF).

The risk of developing HF did not significantly differ between the ILI and DSE groups (hazard ratio [HR], 0.96, 95 percent confidence interval [CI], 0.75–1.23). However, the risk was lower by 39 percent in the subgroup of patients with moderate CRF at baseline (HR, 0.61, 95 percent CI, 0.44–0.83) and by 62 percent in those with high CRF (HR, 0.38, 95 percent CI, 0.24–0.59) relative to those with low CRF.

Among HF subtypes, HFrEF showed no association with baseline CRF. On the other hand, the risk of incident HFpEF was 40-percent lower in moderate CRF and 77-percent lower in the high CRF groups. Baseline body mass index (BMI) was also not related to risk of incident HF, HFpEF or HFrEF.

In the group of participants with repeat CRF assessments (n=3,902), CRF improvements and weight loss over 4 years of follow-up conferred a significant reduction in the risk of HF (HR per 10-percent increase in CRF, 0.90, 95 percent CI, 0.82–0.99; HR per 10-percent decrease in BMI, 0.80, 95 percent CI, 0.69–0.94).

Additional studies investigating the effect of more intense interventions targeting substantial weight loss and CRF improvement are warranted to ascertain the role of lifestyle interventions in modifying HF risk in the present population, the researchers said.