Obesity paradox in heart failure: a heavy matter.

Obesity and heart failure are two of the leading causes of morbidity and mortality in the world. The relationship between obesity and cardiovascular diseases is complex and not fully understood. While the risk of developing heart failure has been shown to be higher in patients who are obese, there is a survival advantage for obese and overweight patients compared with normal weight or low weight patients. This phenomenon was first described by Horwich and was subsequently confirmed in other large trials. The advantage exists irrespective of the type, aetiology, or stage of heart failure. Patients with morbid obesity (body mass index >40 kg/m), however, do not have the same survival advantage of their obese counterparts. There are several alternative indices of obesity available that may be more accurate than body mass index. The role of weight loss in patients with heart failure is unclear; thus, providing sound clinical advice to patients remains difficult. Future prospective trials designed to evaluate the link between obesity and heart failure will help us understand more fully this complex relationship.