Efeitos em curto prazo da cirurgia bariátrica sobre a pressão arterial e modulação autonômica cardíaca em pacientes com obesidade metabolicamente saudável e com obesidade metabolicamente não-saudável

Abstract

Individuals with obesity who are recommended for bariatric surgery (BS) are at increased cardiovascular risk. Comorbidities associated with obesity, such as hypertension and type 2 diabetes, may exacerbate cardiovascular dysfunction. In a bidirectional manner, vascular dysfunction is also aggravated by them, establishing an interdependent cycle. The aim of this study was to evaluate short term changes in blood pressure and cardiac autonomic modulation in patients with metabolically healthy obesity and patients with obesity and hypertension and type 2 diabetes mellitus undergoing bariatric surgery. Subjects were divided into two groups: individuals with metabolically healthy obesity (ObMS, n = 11) and individuals with hypertension and type 2 diabetes mellitus (OHTN-DM, n = 16). Body mass index (BMI), body composition, systolic blood pressure (SBP), diastolic blood pressure (DBP) and electrocardiogram (ECG) were assessed at baseline and 4 weeks after vertical sleeve gastrectomy or Roux-en-Y gastric bypass. The RR intervals were recorded for analysis of heart rate variability (HRV). Data were expressed as mean±SD and groups were compared by unpaired Student’s t-test or Mann-Whitney. Baseline and intervention data were compared by paired t-tests or the Wilcoxon test. Differences were considered significant when p-value was p ≤ 0.05. The ObMS group had a lower mean age (ObMS: 32,1 ± 5, 3 vs OHTN-DM: 44,8 ± 7,5 years) and higher body weight compared to the OHTN-DM group. After 4 weeks, weight loss, BMI reduction and fat percentage reduction were similar between groups. The cardiovascular parameters of heart rate (HR), SBP and DBP were significantly reduced in both groups (p < 0,05). Regarding the HRV variables, there was a significant increase in the RMSSD and pNN50 variables in the OHTN-DM group (p < 0,05). In the spectral analysis, there was a decrease in the LF component of -18,8 ± 15,1 Hz and in the LF/HF ratio of -0,93 ± 0,91 and an increase in the HF component of 20,2 ± 14,6 Hz in the OHTN-DM group. In addition, the OHTN-DM group showed an increase in the SD1 and SD2 variables, but no change in the SD2/SD1 ratio. These results demonstrate that bariatric surgery has a beneficial effect on autonomic modulation and improves parasympathetic activity in individuals with obesity and comorbidities.