We examined the hypothesis that weight loss in heart failure patients is associated with elevated daily energy expenditure. Twelve cachectic patients [age = 73 +/- 6 yr; weight loss = 15 +/- 6 kg; body mass index (BMI) = 21 +/- 5 kg/m2], 13 noncachectic patients (age = 67 +/- 5 yr; BMI = 27 +/- 5 kg/m2), and 50 healthy elderly controls (age = 69 +/- 6 yr; BMI = 26 +/- 4 kg/m2) were studied. Daily energy expenditure and it components were measured using doubly labeled water and indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Fat mass and fat-free mass were lower (P < 0.05) in cachectic patients compared with noncachectic patients and healthy controls. Daily energy expenditure was lower (P < 0.05) in cachectic patients (1,870 +/- 347 kcal/day) compared with noncachectic patients (2,349 +/- 545 kcal/day) and healthy controls (2,543 +/- 449 kcal/day). Differences in daily energy expenditure were primarily due to lower (P < 0.05) physical activity energy expenditure in cachectic (269 +/- 307 kcal/day) and noncachectic patients (416 +/- 361 kcal/day) compared with healthy controls (728 +/- 374 kcal/day). A lower (P < 0.05) resting energy expenditure was also noted in cachectic patients (1,414 +/- 210 kcal/day) compared with noncachectic patients (1,698 +/- 252 kcal/day) and healthy controls (1,561 +/- 223 kcal/day). These findings show that daily energy expenditure is not higher, but significantly lower, in cachectic heart failure patients due to lower physical activity and resting energy expenditure. These results argue against the hypothesis that an abnormally elevated daily energy expenditure is associated with weight loss in heart failure.
Iron deficiency is an independent risk factor of increased myocardial energy expenditure in chronic heart failure patients
