Applicability of predictive equations for resting energy expenditure in obese patients with obstructive sleep apnea

Objective: To investigate the applicability of predictive equations for resting energy expenditure (REE) in obese individuals with obstructive sleep apnea (OSA) and the effects of OSA severity on REE. Materials and methods: Twenty-nine obese men, 41.5 +/- 7 years old, with moderate and severe OSA were recruited. All subjects were submitted to a clinical polysomnography, body composition, and indirect calorimetry measurements. REE was also predicted by three different equations: Harris and Benedict (1919), Cunningham (1990), and DRI (2002). Results: No effects of OSA severity on REE were found. The measured REE (2416.0 +/- 447.1 kcal/day) and the REE predicted by equations were different from each other (F = 2713.88; p < 0.05): Harris and Benedict (2128.0 +/- 245.8 kcal/day), Cunningham (1789.1 +/- 167.8 kcal/day) and DRI (2011.1 +/- 181.4 kcal/day). Pearson correlations showed a moderate positive correlation between the REE measured and predicted by all equations. Conclusion: Our findings suggest that predictive equations for REE underestimate the energy expenditure in obese patients with sleep apnea. Also, no effects of OSA severity on REE were found.