title: The effects of moderate energy restriction on apnoea severity and CVD risk factors in obese patients with obstructive sleep apnoea.
abstract: 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.
authors.affiliation: 1Discipline of Clinical and Experimental Pathophysiology,Rio de Janeiro State University,CEP 20551-030,Rio de Janeiro,Brazil.
authors.forename: Julia Freitas Rodrigues
authors.initials: JF
authors.lastname: Fernandes
authors.affiliation: 1Discipline of Clinical and Experimental Pathophysiology,Rio de Janeiro State University,CEP 20551-030,Rio de Janeiro,Brazil.
authors.forename: Luciene da Silva
authors.initials: Lda S
authors.lastname: Araújo
authors.affiliation: 1Discipline of Clinical and Experimental Pathophysiology,Rio de Janeiro State University,CEP 20551-030,Rio de Janeiro,Brazil.
authors.forename: Sergio Emanuel
authors.initials: SE
authors.lastname: Kaiser
authors.affiliation: 1Discipline of Clinical and Experimental Pathophysiology,Rio de Janeiro State University,CEP 20551-030,Rio de Janeiro,Brazil.
authors.forename: Antonio Felipe
authors.initials: AF
authors.lastname: Sanjuliani
authors.affiliation: 2Department of Applied Nutrition,Nutrition Institute,Rio de Janeiro State University,CEP 20559-900,Rio de Janeiro,Brazil.
authors.forename: Márcia Regina Simas Torres
authors.initials: MR
authors.lastname: Klein
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology*; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D012307:Risk Factors; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology; D055815:Young Adult
keywords: AHI apnoea/hypopnoea index; CG control group; ERG energy restriction group; Endothelial function; Metabolic profile; OSA obstructive sleep apnoea; Obesity; Obstructive sleep apnoea; Sympathetic activity; WC waist circumference; Weight loss; hs-CRP high-sensitivity C-reactive protein