Comparison of body mass index and body surface area as outcome predictors in patients with systolic heart failure

Abstract

p = 0.47; T1, HR = 1.30, p = 0.12; for BSA: T3, reference, T2, HR = 0.96, p = 0.82; T1, HR = 1.15, 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. (Cardiol J 2015; 22, 4: 375-381)

Body surface area as a prognostic marker in chronic heart failure patients: results from the Heart Failure Registry of the Heart Failure Association of the European Society of Cardiology

“…The main mechanism proposed for the obesity paradox in HF is the greater metabolic reserve existing in obese HF patients, in contrast to the catabolic and inflammatory changes leading to cardiac cachexia . However, other contributing factors were suggested, including lower sympathetic activation and earlier presentation of symptoms in the obese HF patients, and confounding factors such as age and gender, which may bias the results …”

“…It may also be that obese patients present earlier in their disease course due to greater functional impairment and are therefore treated earlier. Furthermore, it is possible that confounding factors such as disease severity, lower incidence of smoking, and younger age may account for the inverse relationship between obesity and mortality seen in HF cohorts . Nevertheless, it is still debated whether there is an intrinsic association between obesity and mortality in HF subjects, or whether the obesity paradox is confounded by other uncontrolled factors contributing to its existence …”

“…Furthermore, it is possible that confounding factors such as disease severity, lower incidence of smoking, and younger age may account for the inverse relationship between obesity and mortality seen in HF cohorts. 14,15 Nevertheless, it is still debated whether there is an intrinsic association between obesity and mortality in HF subjects, or whether the obesity paradox is confounded by other uncontrolled factors contributing to its existence. 16 -18 Body mass index (BMI) is the most common anthropometric parameter used in studies assessing obesity in patients with chronic HF, due to its widespread acceptance and ease of use.…”

The obesity paradox in heart failure needs scientific weight

“…active modification of the possible casualties will lead to modification of the observation. In order help clarify the paradox, Zafrir et al [13] evaluated this issue applying body surface area (BSA) instead BMI because BSA is a more precise metabolic mass index than the BMI and is not influenced by abnormal adipose mass. The author's findings indicate that BSA is a stronger predictor of mortality than other measures of body habitus, irrespective of height correction.…”

“…In order to investigate different confounders, Zafrir et al [13] performed adjusted analysis from multivariate variables. They concluded that young age was the main bias factor which makes sense being that younger patients have a higher chance of living longer.…”