Association between underweight and risk of heart failure in diabetes patients

The risk of heart failure (HF) in underweight diabetes mellitus (DM) patients has rarely been studied. We conducted a cohort study to investigate the association between underweight (BMI < 18.5 kg/m²) and BMI change over time and the risk of HF in patients with type 2 DM.

We utilized the health screening data from the National Health Insurance Service and the Korean National Health Screening database from 2009 to 2012, with follow-up until December 2018. Participants with DM were categorized into four groups based on their BMI at 4 years before study inclusion and BMI at the study entry: (1) Always Normal Weight (BMI at 4 years ago/BMI at study entry ≥18.5/≥18.5 kg/m², reference group); (2) Transitioned to Underweight (≥18.5/<18.5 kg/m²); (3) Transitioned to Normal Weight (<18.5/≥18.5 kg/m²) and (4) Always Underweight (<18.5/<18.5 kg/m²). Participants were followed until the development of HF or at the end of the follow-up. Initial screening data included participants with DM who had the health screening during the study period (n = 2,746,079). Participants aged <20 years (n = 390), those who did not undergo health examination 4 years prior (n = 1,306,520), and those with missing data (n = 77,410) were excluded. Participants diagnosed with HF before study participation (n = 81,645) and within 1 year of study enrolment (n = 11,731) were excluded. After applying exclusion criteria, 1,268,383 participants were finally included in the analysis. The primary outcome was the development of HF. We employed Cox proportional hazards models, adjusting for various confounding factors, to assess the risk of developing HF.

Median follow-up duration was 6.88 years and men were 63.16%. The mean ages of each groups were as follows: Always Normal Weight (57.92 ± 11.64 years), Transitioned to Underweight (62 ± 13.5 years), Transitioned to Normal Weight (56.6 ± 15.29 years) and Always Underweight (57.76 ± 15.35 years). In comparison with the Always Normal Weight group (n = 1,245,381, HF = 76,360), Transitioned to Underweight group (≥18.5/<18.5 kg/m², n = 9304, HF = 880, adjusted Hazard Ratio (aHR)1.389, 95% confidence interval (CI) 1.3-1.485) or Transitioned to Normal Weight (<18.5/≥18.5 kg/m², n = 6024, HF = 478, aHR 1.385, 95% CI 1.266-1.515) exhibited an increased risk of HF. The highest risk was observed in the Always Underweight group (<18.5/<18.5 kg/m², n = 7674, HF = 665, aHR 1.612, 95% CI 1.493-1.740).

Underweight was significantly associated with the risk of HF in the DM population. Active surveillance for HF in an underweight DM population is needed.