Effects of energy restricted diet on sleep and metabolic parameters in obese Obstructive Sleep Apnea patients

Rationale: Obstructive sleep apnea (OSA) is highly related to obesity, increasing the risk of metabolic diseases. Weight loss can be considered appropriate supporting treatment, given that the conventional treatments have reduced impact in metabolic risk. Objectives: To evaluate the effects of one month of energy restricted diet with two different macronutrient composition on sleep and metabolic parameters in obese OSA patients. Methods: Thirty-seven OSA obese male were randomized in two groups of on month energy restricted diet. All participants were submitted to a nocturnal polysomnography, body composition and food intake evaluations before and after the intervention. Diets were design to create a 30% deficit in total energy expenditure and 1.6g of protein/kg/day (PTN group) or 0.8g of protein/kg/day (CHO group). Measurements and Results: Changes in body mass (-3.7±2.0% for CHO group, and -4.0±1.5% for PTN group), anthropometrics and body composition was similar in both groups. Our results showed an improvement of 38% in AHI in CHO group and 46% in PTN group. All OSA parameters were improved similarly in both diet intervention groups. Also, the time spent in SaO2 <90% reduced in both groups. Both diets resulted in improvements in glucose and lipids metabolism. Conclusions: We conclude that only one-month of moderate energy restricted diet can result in a significant improvement in OSA severity and reductions in metabolic risk. Increase of protein intake during an energy restricted diet has no beneficial improvements in sleep or biochemical parameters than a normal protein diet.