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Comparison of body mass index and body surface area as outcome predictors in patients with systolic heart failure
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Abstract
Background: We investigated whether the ‘obesity paradox’ in heart failure (HF) is influenced by common confounders, and assessed if body surface area (BSA) may correlate more closely than body mass index (BMI) with prognosis.
Methods: We studied 630 systolic HF patients at their initial visit to the HF clinic. Body size was measured by BMI and BSA. The association between body indices and mortality was assessed by Cox proportional-hazard analyses.
Results: There were 248 deaths during mean follow-up of 39 months. A progressive inverse association of BMI and BSA tertiles (T1–T3) with mortality risk was observed (for BSA: T3, reference, T2, hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.01–1.95, p = 0.04 and T1, HR = 1.78, 95% CI 1.29–2.45, p < 0.001; for BMI: T3, reference, T2, HR = 1.29, 95% CI 0.92–1.79, p = 0.13 and T1, HR = 1.66, 95% CI 1.21–2.27, p = 0.002). The obesity paradox was attenuated after multivariate adjustment, and did not persist after adjustment for age alone (for BMI: T3, reference, T2, HR = 1.13, 95% CI 0.81–1.58, p = 0.47; T1, HR = 1.30, 95% CI 0.94–1.80, p = 0.12; for BSA: T3, reference, T2, HR = 0.96, 95% CI 0.68–1.35, p = 0.82; T1, HR = 1.15, 95% CI 0.82–1.63, p = 0.42).
Conclusions: BSA provides prognostic information similar to BMI in systolic HF. However, the obesity paradox of both BMI and BSA in HF may be confounded by the younger age of the obese patients.
Abstract
Background: We investigated whether the ‘obesity paradox’ in heart failure (HF) is influenced by common confounders, and assessed if body surface area (BSA) may correlate more closely than body mass index (BMI) with prognosis.
Methods: We studied 630 systolic HF patients at their initial visit to the HF clinic. Body size was measured by BMI and BSA. The association between body indices and mortality was assessed by Cox proportional-hazard analyses.
Results: There were 248 deaths during mean follow-up of 39 months. A progressive inverse association of BMI and BSA tertiles (T1–T3) with mortality risk was observed (for BSA: T3, reference, T2, hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.01–1.95, p = 0.04 and T1, HR = 1.78, 95% CI 1.29–2.45, p < 0.001; for BMI: T3, reference, T2, HR = 1.29, 95% CI 0.92–1.79, p = 0.13 and T1, HR = 1.66, 95% CI 1.21–2.27, p = 0.002). The obesity paradox was attenuated after multivariate adjustment, and did not persist after adjustment for age alone (for BMI: T3, reference, T2, HR = 1.13, 95% CI 0.81–1.58, p = 0.47; T1, HR = 1.30, 95% CI 0.94–1.80, p = 0.12; for BSA: T3, reference, T2, HR = 0.96, 95% CI 0.68–1.35, p = 0.82; T1, HR = 1.15, 95% CI 0.82–1.63, p = 0.42).
Conclusions: BSA provides prognostic information similar to BMI in systolic HF. However, the obesity paradox of both BMI and BSA in HF may be confounded by the younger age of the obese patients.
Keywords
systolic heart failure, body mass index, body surface area, prognosis, confounding factors
About this articleTitle
Comparison of body mass index and body surface area as outcome predictors in patients with systolic heart failure
Journal
Issue
Pages
375-381
Published online
2015-08-28
Page views
2055
Article views/downloads
2310
DOI
10.5603/CJ.a2014.0104
Pubmed
Bibliographic record
Cardiol J 2015;22(4):375-381.
Keywords
systolic heart failure
body mass index
body surface area
prognosis
confounding factors
Authors
Barak Zafrir
Yaron Goren
Nabeeh Salman
Offer Amir
