Effect of Tumor Load on Energy Expenditure in Patients With Pancreatic Cancer

Abstract

Increased metabolic rate may play a role in cancer cachexia, especially when caloric intake is significantly reduced. We studied the effect of tumor load on resting energy expenditure (REE) in patients with pancreatic cancer after normalizing for their daily caloric intake and body composition. The cross-sectional study included 45 patients with pancreatic cancer (15 postoperation) and 75 controls. Resting energy expenditure was measured by indirect calorimetry, body composition was measured by dual-energy x-ray absorptiometry, and energy intake was measured by 3-day food records. There were no differences between pancreatic cancer patients who underwent surgery and those who did not in any of the anthropometric or metabolic parameters tested. Body mass index, lean body mass, body fat percentage, and energy intake were significantly lower in patients with pancreatic cancer (P < 0.0001) compared with healthy controls. Resting energy expenditure and the respiratory quotient were significantly lower in patients (P < 0.0001 and P < 0.025, respectively). There were no differences in REE between patients and controls when normalized by lean body mass. Respiratory quotients were significantly lower in patients who underwent surgery and in those who did not compared with controls. Pancreatic cancer does not increase REE above the normal levels nor does tumor burden contribute to increasing REE. Decreased daily energy intake of our patients may have reduced measured REE.