Avaliação do efeito da perda ponderal sobre a função endotelial e rigidez arterial em indivíduos com obesidade e apneia obstrutiva do sono

Abstract

Obesity is a chronic disease and considered one of the most evident and neglected public health problems. Obesity and obstructive sleep apnea (OSA) may have synergistic effects on the pathogenesis or progression of cardiovascular diseases. Although weight loss induced by negative energy balance is associated with improvement in metabolic, inflammatory and vascular parameters, it is not yet known whether these effects vary according to the presence and/or severity of OSA. The study aimed to evaluate the effect of weight loss through nutritional intervention on vascular function, sympathetic tone, metabolic and inflammatory biomarkers in individuals with obesity and moderate-severe OSA. Participants of both sexes, aged between 40 and 70 years and body mass index (BMI) ≥ 30 and < 40 kg/m² were followed up and instructed to follow a low-calorie diet (-800 kcal/day) for 16 weeks. Before and after the intervention, the participants were submitted to clinical, biochemical and nutritional (anthropometry and bioimpedance) evaluation, sleep study, autonomic, structural and functional vascular system. The sleep study was performed using a home polysomnography device (Watch-PAT 200®) and the Epworth questionnaire was applied. Assessment of the autonomic system was performed using a heart rate meter (Polar® RS800), endothelial function was assessed by microvascular reactivity and flow-mediated dilation in the brachial artery. Oscillometric analysis of pulse waves and arterial stiffness using the Mobil-O-Graph® and the measurement of carotid intima-media thickness were performed with an ultrasound device. Food intake was assessed using a food frequency questionnaire. Initially, 86 subjects were selected and 76 were included and divided into two groups, based on the apnea-hypopnea index (AHI): mild-absent (MA; n=30) OSA group, AHI <15 events/h and moderate-severe (MS; n=46) OSA group, AHI ≥ 15 events/h. In the cross-sectional analysis, the mean age was 52±8 years, BMI was 34.1±2.7 kg/m2 and AHI was 22±16 events/h, with 75% being female. Regarding the baseline data, a positive correlation was found between the AHI and the pulse wave velocity (r= 0.261; p= 0.024) and with the LF/HF ratio (r= 0.396; p <0.001). A total of 70 participants completed the first 8 weeks of nutritional intervention and both groups observed reduced in blood pressure (BP), BMI, body fat and heart rate (HR). Additionally, the group with AOS MA showed a reduction in vascular parameters. After 16 weeks, 60 participants completed the calorie restriction period with similar weight loss (-5.0 (-5.2 ‒ -1.7) vs -3.2 (-6.3 ‒ -1.7) %, p= 0.532), with no significant difference. The groups showed a reduction in BP and body composition, and an improvement in insulin resistance and inflammatory profile. The MS OSA group showed an improvement in the sleep quality and indices, endothelial function, central and peripheral BP. In conclusion, individuals with obesity and MS OSA required a longer time of nutritional intervention to obtain greater benefits in sleep quality and vascular functions than those with MA OSA