The effects of moderate energy restriction on apnoea severity and CVD risk factors in obese patients with obstructive sleep apnoea

• Published in: British journal of nutrition Vol. 114; no. 12; pp. 2022 - 2031
• Main Authors: Fernandes, Julia Freitas Rodrigues, Araújo, Luciene da Silva, Kaiser, Sergio Emanuel, Sanjuliani, Antonio Felipe, Klein, Márcia Regina Simas Torres
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.12.2015
• Subjects: Adult; Blood pressure; Body weight; Cardiovascular disease; Cardiovascular Diseases - complications; Cardiovascular Diseases - epidemiology; Dietary restrictions; Energy; Energy Intake; Female; Human and Clinical Nutrition; Humans; Male; Middle Aged; Nutrition; Obesity; Obesity - complications; Risk Factors; Severity of Illness Index; Sleep; Sleep apnea; Sleep Apnea, Obstructive - complications; Sleep Apnea, Obstructive - physiopathology; Weight control; Young Adult; Obesity; Sympathetic activity; Obstructive sleep apnoea; Metabolic profile; Endothelial function; Weight loss; OSA obstructive sleep apnoea; ERG energy restriction group; CG control group; AHI apnoea/hypopnoea index; WC waist circumference; hs-CRP high-sensitivity C-reactive protein
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114515004018

Nutritional intervention for weight loss is one of the treatment options for obstructive sleep apnoea (OSA) in patients with overweight or obesity. However, the effects of moderate energy restriction on OSA severity are not yet known. The present study aimed to evaluate the effects of moderate energy restriction on OSA severity and CVD risk factors in obese patients with OSA. In this 16-week randomised clinical trial, twenty-one obese subjects aged 20–55 years and presenting an apnoea/hypopnoea index (AHI)≥5 events/h were randomised into two groups: the energy restriction group (ERG) and the control group (CG). The ERG was instructed to follow an energy-restricted diet −3347·2 kJ/d (−800 kcal/d) and the CG was advised not to change their food intake. At the beginning and at the end of the study, participants underwent evaluation of the following: OSA (Watch-PAT200®), nutritional parameters, blood pressure, sympathetic activity, inflammatory biomarkers, metabolic profile and endothelial function. The ERG (n 11), compared with the CG (n 10), had a significantly greater reduction in body weight (Cohen’s d=−1·19; P<0·001), in AHI (Cohen’s d=−0·95; P=0·04) and in plasma concentrations of adrenaline (Cohen’s d=−1·02; P=0·04) as well as a significantly greater increase in minimum O2 saturation (Cohen’s d=1·08; P=0·03). Although energy restriction was not associated with significant improvements in CVD risk factors, medium-to-large effect sizes were observed, suggesting that the statistically non-significant difference between groups may be due to the small sample size. This study suggests that in obese patients with OSA, moderate energy restriction is able to reduce the parameters of OSA severity and sympathetic activity.