The obesity paradox in heart failure patients with preserved versus reduced ejection fraction: a meta-analysis of individual patient data

• Published in: International Journal of Obesity Vol. 38; no. 8; pp. 1110 - 1114
• Main Authors: Padwal, R, McAlister, F A, McMurray, J J V, Cowie, M R, Rich, M, Pocock, S, Swedberg, K, Maggioni, A, Gamble, G, Ariti, C, Earle, N, Whalley, G, Poppe, K K, Doughty, R N, Bayes-Genis, A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2014; Nature Publishing Group
• Subjects: 692/699/2743/393; 692/699/75/230; 692/700/139/2818; 692/700/1750; Adult; Biological and medical sciences; Blood pressure; Body Mass Index; Body size; Cardiac output; Cardiology. Vascular system; Cardiovascular system; Clinical Medicine; Comorbidity; Confidence intervals; Congestive heart failure; Diabetes mellitus; Ejection fraction; Epidemiology; Etiology; Failure analysis; Female; Hazards; Health aspects; Health hazards; Health Promotion and Disease Prevention; Heart; Heart failure; Heart Failure - mortality; Heart Failure - physiopathology; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; Hypertension; Internal Medicine; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Ischemia; Klinisk medicin; Male; Medical sciences; Medicine; Medicine & Public Health; Meta-analysis; Metabolic Diseases; Mortality; Obesity; Obesity - complications; Obesity - mortality; original-article; Paradoxes; Patient outcomes; Patients; Physiological aspects; Prognosis; Proportional Hazards Models; Public Health; Risk Factors; Statistical models; Stroke Volume; Survival; Survival Analysis; Systematic review; Ventricle; heart failure; ejection fraction; obesity paradox; prognosis; body mass index; Medical data; Human; Heart failure; Obesity; Prognosis; Nutrition; Nutrition disorder; Cardiovascular disease; Patient; Metabolic diseases; Metaanalysis; Body mass index; Reduction; Heart disease; Hemodynamics; Nutritional status; Comparative study; Ejection fraction
• ISSN: 0307-0565; 1476-5497; 1476-5497
• DOI: 10.1038/ijo.2013.203

Background: In heart failure (HF), obesity, defined as body mass index (BMI) ⩾30 kg m −2 , is paradoxically associated with higher survival rates compared with normal-weight patients (the ‘obesity paradox’). We sought to determine if the obesity paradox differed by HF subtype (reduced ejection fraction (HF-REF) versus preserved ejection fraction (HF-PEF)). Patients and Methods: A sub-analysis of the MAGGIC meta-analysis of patient-level data from 14 HF studies was performed. Subjects were divided into five BMI groups: <22.5, 22.5–24.9 (referent), 25–29.9, 30–34.9 and ⩾35 kg m −2 . Cox proportional hazards models adjusted for age, sex, aetiology (ischaemic or non-ischaemic), hypertension, diabetes and baseline blood pressure, stratified by study, were used to examine the independent association between BMI and 3-year total mortality. Analyses were conducted for the overall group and within HF-REF and HF-PEF groups. Results: BMI data were available for 23 967 subjects (mean age, 66.8 years; 32% women; 46% NYHA Class II; 50% Class III) and 5609 (23%) died by 3 years. Obese patients were younger, more likely to receive cardiovascular (CV) drug treatment, and had higher comorbidity burdens. Compared with BMI levels between 22.5 and 24.9 kg m −2 , the adjusted relative hazards for 3-year mortality in subjects with HF-REF were: hazard ratios (HR)=1.31 (95% confidence interval=1.15–1.50) for BMI <22.5, 0.85 (0.76–0.96) for BMI 25.0–29.9, 0.64 (0.55–0.74) for BMI 30.0–34.9 and 0.95 (0.78–1.15) for BMI ⩾35. Corresponding adjusted HRs for those with HF-PEF were: 1.12 (95% confidence interval=0.80–1.57) for BMI <22.5, 0.74 (0.56–0.97) for BMI 25.0–29.9, 0.64 (0.46–0.88) for BMI 30.0–34.9 and 0.71 (0.49–1.05) for BMI ⩾35. Conclusions: In patients with chronic HF, the obesity paradox was present in both those with reduced and preserved ventricular systolic function. Mortality in both HF subtypes was U-shaped, with a nadir at 30.0–34.9 kg m −2 .