Associations of BMI with mortality in HFpEF patients with concomitant diabetes with insulin versus non-insulin treatment

Obesity in heart failure with preserved ejection fraction with and without diabetes: risk factor or innocent bystander?

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a condition that commonly coexists with type 2 diabetes mellitus (T2DM) and obesity. Whether the obesity-related survival benefit generally observed in HFpEF extends to individuals with concomitant T2DM is unclear. This study sought to examine the prognostic role of overweight and obesity in a large cohort of HFpEF with and without T2DM.

METHODS AND RESULTS

This large-scale cohort study included patients with HFpEF enrolled between 2010 and 2020. The relationship between body mass index (BMI), T2DM, and survival was assessed. A total of 6744 individuals with HFpEF were included, of which 1702 (25%) had T2DM. Patients with T2DM had higher BMI values (29.4 kg/m2 vs. 27.1 kg/m2, P < 0.001), higher N-terminal pro-brain natriuretic peptide values (864 mg/dL vs. 724 mg/dL, P < 0.001), and a higher prevalence of numerous risk factors/comorbidities than those without T2DM. During a median follow-up time of 47 months (Q1-Q3: 20-80), 2014 (30%) patients died. Patients with T2DM had a higher incidence of fatal events compared with those without T2DM, with a mortality rate of 39.2% and 26.7%, respectively (P < 0.001). In the overall cohort, using the BMI category 22.5-24.9 kg/m2 as the reference group, the unadjusted hazard ratio (HR) for all-cause death was increased in patients with BMI <22.5 kg/m2 [HR: 1.27 (confidence interval 1.09-1.48), P = 0.003] and decreased in BMI categories ≥25 kg/m2. After multivariate adjustment, BMI remained significantly inversely associated with survival in non-T2DM, whereas survival was unaltered at a wide range of BMI in patients with T2DM.

CONCLUSION

Among the various phenotypes of HFpEF, the T2DM phenotype is specifically associated with a greater disease burden. Higher BMI is linked to improved survival in HFpEF overall, while this effect neutralises in patients with concomitant T2DM. Advising BMI-based weight targets and weight loss may be pursued with different intensity in the management of HFpEF, particularly in the presence of T2DM.

U-shaped association between body mass index and ejection fraction in intensive care unit patients with heart failure

AIMS

There are limited data about the relationship between body mass index (BMI) and left ventricular ejection fraction (EF) in patients with heart failure (HF). The study aims to assess the correlation between BMI and left ventricular EF under HF conditions.

METHODS AND RESULTS

We derived the data from the Dryad Digital Repository for analysis, and the information of the original patients was obtained from the MIMIC-III database by the data uploader. We performed smooth curve and two piecewise linear regression analyses to evaluate the association between BMI and EF in HF patients. A total of 962 participants were included in this study, with age of 73.7 ± 13.5 years, and 475 participants were male (49.4%). The results of the smooth curve supported a U-shaped relationship between BMI and EF, and the inflection point was found to be a BMI of 23.3 kg/m² in these HF patients. After adjusting for potential confounders, we found that EF decreased with increasing BMI up to the inflection point (β = -0.7, 95% CI -1.3 to -0.1, P = 0.028), whereas beyond the turning point, the relationship between EF and BMI showed a positive correlation (β = 0.2, 95% CI 0.1-0.3 P < 0.001). Importantly, ischaemic heart disease (interaction P = 0.0499) and hyperlipidaemia (interaction P = 0.0162) affected the association between BMI and EF in the lower BMI group (BMI < 23.3 kg/m² ), although only diabetes mellitus (interaction P = 0.0255) altered the association between BMI and EF in the higher BMI group (BMI ≥ 23.3 kg/m² ).

CONCLUSIONS

In addition to higher BMI, we also found that lower BMI is related to higher EF in intensive care unit patients with HF, supporting a U-shaped association between BMI and EF.