The Paradox of Obesity in Patients with Heart Failure

Abstract

Purpose Heart failure (HF) patients often have comorbid conditions that confound management and adversely affect prognosis. The purpose of this study was to determine whether the obesity paradox is also present in hospitalized HF patients in an integrated healthcare system. Data sources A cohort of 2707 patients with a primary diagnosis of HF was identified within an integrated, 20‐hospital healthcare system. Patients were identified by ICD‐9 codes or a left ventricular ejection fraction ≤40% dating back to 1995. Body mass index (BMI) was calculated using the first measured height and weight when hospitalized with HF. Survival rates were calculated using Kaplan Meier estimation. Hazard ratios for 3‐year mortality with 95% confidence intervals were assessed using Cox regression, controlling for age, gender, and severity of illness at time of diagnosis. Conclusions Three‐year survival rates paradoxically improved for patients with increasing BMI. Survival rates for the larger three BMI quartiles were significantly better than for the lowest quartile after adjusting for severity of illness, age, and gender. Implications for practice While obesity increases the risk of developing HF approximately twofold, reports involving stable outpatients suggest that obesity is associated with improved survival after the development of HF. This finding is paradoxical because obesity increases the risk and worsens the prognosis of other cardiovascular diseases.

Accelerated Recovery from Acute Hypoxia in Obese Mice Is Due to Obesity-Associated Up-Regulation of Interleukin-1 Receptor Antagonist

“…Given today's antifat cultural environment (36), this assertion by Horwich et al is especially controversial, but recent work has supported an obesity paradox in heart failure (25,26). Whereas Habbu et al (37) questioned the validity of an obesity survival advantage in heart failure, their counterargument is weakened by the poor prognosis seen in those who suffer from cardiac cachexia (38).…”

“…In humans, obesity is associated with improved survival for certain diseases and conditions including heart failure (25,26), coronary artery disease (27,28), chronic kidney disease (29), and rheumatoid arthritis (30,31). In terms of mechanism, the enhanced survival in rheumatoid arthritis is the easiest to understand because anti-IL-1 therapy in the form of a derivitized IL-1RA (anakinra) is used clinically in the treatment of rheumatoid arthritis (32).…”

Mechanisms of vascular adaptation to obesity

“…On the contrary, it is possible that the presence of obesity has potentially a key role in maintaining and augmenting 11 vasodilator capacity of coronary microvessels. Interestingly, clinical studies on obese patients with coronary heart disease have found an unexpectedly favorable prognosis on acute cardiovascular outcome, with the worst prognosis associated with either underweight or morbidly obese patients (27,28,32).…”

“…Although obesity is widely accepted as a risk factor for coronary heart disease and heart failure, emerging evidence supports a protective role of obesity once patients have developed cardiovascular disease (28,32).…”

“…A growing number of recent reports document a statistically significant survival benefit in obese patients once they have been diagnosed with cardiovascular diseases (27,28,32). The conclusion that obesity may both elicit cardiovascular disease and protect from cardiovascular death now clearly requires further investigation at cellular, molecular, and systematic levels.…”