Ângulo de fase da bioimpedância e o estado inflamatório na doença arterial coronariana

Abstract

Coronary artery disease (CAD) is an important public health problem as it is one of the main causes of morbidity and mortality. It is therefore necessary to have tools that assess the cellular health of patients with CAD and that assist in the monitoring of inflammatory processes in order to early identify individuals at risk for acute events and future cardiovascular complications. Evidence points to the phase angle (PhA) as an indicator of inflammation in several health situations, however, in coronary disease it has not been investigated. OBJECTIVE: To investigate the association of phase angle with inflammatory status in patients with chronic coronary artery disease. METHODS: The thesis consists of two manuscripts: a systematic review and an original study. Systematic review: Searches were carried out in MEDLINE, EMBASE, Cochrane, Scielo, LILACS, CINAHL, Scopus and Web of Science databases. The selection was performed independently by two reviewers according to the eligibility criteria, as well as the analysis of the risk of bias and the quality of the included studies. The results were synthesized and described in the review. As no studies were found in patients with CAD, we explored articles in patients with cardiometabolic diseases and individuals without chronic diseases. Original study: The sample consisted of patients with chronic coronary artery disease, treated at the Hypercholesterolemia Outpatient Clinic of the Cardiology Service of Hospital São Lucas, PUCRS. The phase angle was evaluated using the Biospace equipment, model Inbody S10, from Ottoboni. The inflammatory markers evaluated were: Ultrasensitive c-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor alpha (TNF-α). A control group with individuals without CAD was included for comparative analysis. In the statistical analysis, correlation of PhA and predictor variables was verified with Pearson's and Spearman's correlation coefficients. To identify whether the inflammatory markers influenced the phase angle, linear regression was used. RESULTS: Systematic review: 755 articles were identified in the research, and 11 articles were included, totaling 50,787 participants. The inflammatory markers investigated in the studies were: CRP, TNF-α, IL-6 and IL-33. In subjects with cardiometabolic disease, phase angle was negatively associated with CRP, TNF-α and IL-6 in 71.4%, 50% and 100% of the studies, respectively. In individuals without chronic disease, a negative association of PhA with CRP, TNF-α and IL-6 was observed in 75%, 100% and 100% of the studies, respectively. Original study: 82 individuals participated in the study, 60 from the CAD group and 22 from the control group. The general mean of the phase angle was 5.8±0.8º, not differing between the groups (p=0,933). Only IL-6 was significantly higher among CAD patients (p=0,002). PhA did not correlate with any of the inflammatory markers evaluated (p>0,05). CONCLUSION: The results of the systematic review suggest a negative association of PhA with inflammatory markers CRP, IL-6 TNF-α in individuals with cardiometabolic diseases and without chronic disease. However, in the original study, no association was found between PhA and inflammatory status in patients with chronic CAD, requiring further studies in patients with no previous treatment or in an unstable phase of the disease.