Perils of weight loss: the advantage of being obese in patients with heart failure.

Evaluation of: Pocock SJ, McMurray JJV, Dobson J et al. Weight loss and mortality risk in patients with chronic heart failure in the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity (CHARM) programme. Eur. Heart J. 29, 2641-2650 (2008). Among patients with heart failure, the usual association between obesity and reduced survival appears to be turned on its head. Increasing numbers of studies appear to confirm the apparent protective effect of the 'obesity paradox' in heart failure. The adverse effects of weight loss and cachexia have been recognized among patients with chronic disease. The paper under evaluation clarifies and offers further insight into the impact of BMI and weight loss on prognosis in a large sample of heart failure patients. The results confirm and extend previous knowledge. They raise many questions, not only regarding the underlying pathophysiology that leads to this counterintuitive relationship observed in the obese heart failure group, but also as to how we should best approach and advise these patients on weight management in day-to-day practice.