Estudo da atividade nervosa autonômica durante o sono através da análise espectral Wavelet da variabilidade da frequência cardíaca em sujeitos obesos mórbidos submetidos à cirurgia bariátrica

Abstract

Obesity is one of the most serious public health problems is now considered a multifactorial disease in epidemiological characteristics. It is characterized by the accumulation of body fat in order to compromise the health and develops through the interaction of genetic, environmental, socioeconomic, cultural, metabolic and psychological affects all social classes and all different age groups including an increase in the number of cases childhood obesity. Obesity is classified as grade III when the body mass index, obtained by dividing weight by the square of height, reach a value of ≥ 40 kg / m². In Brazil the most used surgical procedures for obesity surgery are techniques that combine restrictive and disabsortives methods as the Fobi-Capella and Scopinaro. The syndrome of obstructive sleep apnea is often associated with obesity is a risk factor for hypertension and coronary artery disease and recent studies have shown that the syndrome of obstructive sleep apnea is an independent risk factor for cardiovascular disease. The correlation between the cardiovascular and cardiopulmonary disorders of sleep can be explained by the collapse of the airway during sleep is associated with the increased work of breathing and changes in nasal and oral airflow triggering hypoxemia and hypercapnia, leading to repeated awakenings during sleep causing stimulation of the sympathetic nervous system and hypertension. The aim of this study was to assess heart rate variability by spectral analysis wavelet which aims to identify the different frequencies that can be obtained from the signal studied during sleep in morbidly obese candidates for bariatric surgery. We evaluated 14 individuals of both sexes and data collection included body mass index, full nocturnal polysomnography and wavelet spectral analysis of heart rate variability. We obtained results as follows: age 36.07 ± 10.97, BMI 48.68 ± 5.64;, an apnea-hypopnea index 28.7 ± 25.9, 829.20 ± 82.84 RR interval; indices of the spectral analysis of variability heart rate showed a predominance of sympathetic nervous system on the parasympathetic signal obtained after interpretation and analysis through the behavior of the frequencies. After 60 days of surgery, 14 subjects repeated the data collection and polysomnography and showed decreased body mass index 41.92 ± 5.72, apnea index and hypopnea index 16.9 ± 17.4, improved heart rate variability; interval RR 972.24 ± 146.20. It was found that morbidly obese subjects candidates for bariatric surgery have a high prevalence of the syndrome and obstructive sleep apnea have changes in HRV during sleep with a predominance of sympathetic activity. With the reduction in weight after 60 days of bariatric surgery, there was improvement in anthropometric values in polysomnographic variables in heart rate variability and distribution of frequencies obtained by the wavelet spectral analysis using graphs and histograms showing a more harmonic and uniform distribution characterizing a physiological behavior of the autonomic nervous system more balanced.