Very low BMI at discharge ups mortality risk in patients with ADHF

Being discharged with a very low body mass index (BMI) worsens survival outlook in patients with acute decompensated heart failure (ADHF), reports a recent Japan study.

Researchers enrolled 3,509 ADHF patients who were divided into five groups according to discharge BMI: severely underweight (BMI <16 kg/m²), underweight (BMI ≥16 to <18.5 kg/m²), normal (BMI ≥18.5 to <25 kg/m²), overweight (BMI, ≥25 to <30 kg/m²), and obese (BMI ≥30 kg/m²). Outcomes include all-cause death after discharge, cardiovascular and non-cardiovascular deaths, and HF hospitalizations.

The cumulative 1-year incidence rate of all-cause deaths was highest in severely underweight (36.3 percent) patients and lowest in those who were overweight (7.9 percent). There was a significant difference among the Kaplan-Meier survival curves of all groups (log-rank p<0.001).

Adjusting for confounders revealed that being severely underweight (hazard ratio [HR], 2.32, 95 percent confidence interval [CI], 1.83–2.94; p<0.001) and underweight (HR, 1.31, 95 percent CI, 1.08–1.59; p=0.005) were significant risk factors for all-cause mortality, as compared to normal BMI. Being overweight or obese had no such effects.

Similarly, the risk of cardiovascular death (HR, 2.23, 95 percent CI, 1.64–3.03; p<0.001) and non-cardiovascular deaths (HR, 2.43, 95 percent CI, 1.67–3.54; p<0.001), but not HF hospitalizations, were significantly elevated in patients who were severely underweight at discharge. For all three outcomes, being overweight or obese had no meaningful impact.

The principal findings remained largely unchanged even when researchers instead changed the BMI cutoff values to the standards used for Asian populations.