Exercise tolerance can explain the obesity paradox in patients with systolic heart failure: data from the MECKI Score Research Group

Abstract

Aims Obesity has been found to be protective in heart failure (HF), a finding leading to the concept of an obesity paradox. We hypothesized that a preserved cardiorespiratory fitness in obese HF patients may affect the relationship between survival and body mass index (BMI) and explain the obesity paradox in HF. Methods and results A total of 4623 systolic HF patients (LVEF 31.5 ± 9.5%, BMI 26.2 ± 3.6 kg/m2) were recruited and prospectively followed in 24 Italian HF centres belonging to the MECKI Score Research Group. Besides full clinical examination, patients underwent maximal cardiopulmonary exercise test at study enrolment. Median follow‐up was 1113 (553–1803) days. The study population was divided according to BMI (<25, 25–30, >30 to ≤35 kg/m2) and predicted peak oxygen consumption (peak VO2, <50%, 50–80%, >80%). Study endpoints were all‐cause and cardiovascular deaths including urgent cardiac transplant. All‐cause and cardiovascular deaths occurred in 951 (28.6%, 57.4 per person‐years) and 802 cases (17.4%, 48.4 per 1000 person‐years), respectively. In the high BMI groups, several prognostic parameters presented better values [LVEF, peak VO2, ventilation/carbon dioxide slope, renal function, and haemoglobin (P < 0.01)] compared with the lower BMI groups. Both BMI and peak VO2 were significant positive predictors of longer survival: both higher BMI and peak VO2 groups showed lower mortality (P < 0.001). At multivariable analysis and using a matching procedure (age, gender, LVEF, and peak VO2), the protective role of BMI disappeared. Conclusion Exercise tolerance affects the relationship between BMI and survival. Cardiorespiratory fitness mitigates the obesity paradox observed in HF patients.

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Prevalence of modifiable risk factors and relation to stroke and death in patients with atrial fibrillation: A report from the China atrial fibrillation registry study

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Obesity in heart failure: is it time to rethink the paradox?

“…Recently, in a large database of HF patients with left ventricular systolic dysfunction, when we investigated the role of exercise capacity vs. body mass index (BMI), we observed that the former (i.e. peak VO 2 ) maintained its prognostic value in all BMI groups, supporting the pivotal role of exercise tolerance in HF patients regardless of BMI. Consequently, when peak VO 2 was considered as a covariate in the survival analysis, the so‐called ‘obesity paradox’ was lost.…”