Associação de obesidade sarcopênica, indicadores de composição corporal, de variabilidade da frequência cardíaca e de esforço no teste do degrau de seis minutos com a severidade da Síndrome da Apneia Obstrutiva do Sono: Um estudo transversal

Abstract

Introduction: Obstructive sleep apnea syndrome (OSAS) is the most common sleep- related respiratory disorder in the world, with different levels of severity. The literature indicates that increased body fat can increase energy expenditure, alter heart rate variability during sleep and wakefulness and affects the severity of the syndrome. Thus, there is a greater risk of muscle catabolism, negatively influencing cellular health, measured by the phase angle in bioelectrical impedance. However, few studies have expanded the assessment of body composition in relation to sarcopenic obesity in this population. In addition, the results of current research are also conflicting when analyzing the impacts of OSAS severity on metabolic and physical performance during stress tests. Objective: To investigate the association of indicators of body composition, heart rate variability, and stress in the six-minute step test with the severity of OSAS. Methods: Cross-sectional, quantitative study that took place between December 2023 and August 2024, with a single sample of 37 people diagnosed with OSAS, age 53,7 ± 13,8 years, minimum age 28 years and maximum age 78 years, confirmed by type 1 polysomnography. Data collection was performed in two phases: a) Rest, using bioelectrical impedance (Biodynamics BIA 450, Biodynamics Corporation, Washington, USA) to collect body composition data, indirect calorimetry (Quark CPET, Cosmed, Italy) to collect resting metabolic rate and time and frequency domain variables of heart rate variability using a heart rate monitor (SmartLab, HMMGroup, Germany); b) Exercise, using the 6-minute step test with a gas analyzer (Quark CPET, Cosmed, Italy) breath by breath to assess physical and metabolic effort. To determine data normality, the Shapiro-Wilk test was used, with normal data represented by mean and standard deviation and non-normal data represented by median and interquartile range. For multivariate data analysis, principal component analysis (PCA) was used, employing the varimax rotation algorithm to create the components. The reduced value of each component was used to perform a simple linear regression analysis. Results: Thirty-seven individuals with OSAS (54.05% men), BMI 31.1 ± 5.31 kg/m2 and AHI 31.3 (11.3-61.6) were evaluated. The PCA analysis created 6 principal components (PC), which are: 1st PC: body composition; 2nd PC: cellular health; 3rd PC: physical effort; 4th PC: ventilatory reasons; 5th PC: sympathovagal stimulation; 6th PC: sympathovagal stimulation (very low frequency). The body composition indicators component (BMI, neck circumference, resting metabolic rate, body resistance, and capacitance) was associated with higher AHI (F[3,32] = 3.05; p = 0.01), with an adjusted r2 value of 0.22. Conclusion: Body composition is associated with the severity of OSAS, while the components of cellular health, physical effort, ventilatory ratios, sympathovagal stimulation, and very low frequency sympathovagal stimulation were not associated with the severity of the syndrome.