Heart rate variability during the AVD-Glittre test in women with rheumatoid arthritis

Abstract

Introduction: Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that affects the joints, bilaterally, causing polymyalgia. Its main characteristic is synovial inflammation, which can progress to erosion of the cartilage and bone, followed by joint deformities. Among the problems that the RA brings, it can be observed a worsening in the functional capacity to perform activities of daily living (ADLs). From this, it is fundamental to analyze, through a specific test to classify the functional capacity, the impact that the RA has on the life of these individuals. Objective: The objective of this study was to analyze the impact of peripheral muscle function, sympatho-vagal behavior on functional capacity in RA women. Methods: The participants underwent an assessment of the functional capacity associated with the ability to perform ADLs using the Glittre ADL-test (GA-T) and, also, the analysis of sympathetic-vagal balance through heart rate variability (HRV). They also underwent physical functioning assessment through the Health Assessment Questionnaire Disability Index (HAQ-DI) and handgrip strength (HGS) and quadriceps strength (QS) measures. Results: This cross-sectional study enrolled 20 women (median [interquartile range]: age 55 [47.5–68.8] years) with RA (time since diagnosis: 15 [6.50–23.5] years). The GA-T time exhibited significant correlations with the following HRV indices: root mean square of successive differences (RMSSD, rs = -0.451, P = 0.041), proportion of iRR differing by > 50 ms from previous intervals (pNN50, rs = -0.697, P = 0.0006), high frequency (HF, rs = -0.693, P = 0.0007), standard deviation of the points perpendicular to the line-of-identity (SD1, rs = -0.476, P = 0.034), and approximate entropy (ApEn, rs = 0.545, P = 0.013). In addition, the HAQ-DI exhibited significant correlations with the following HRV indices: pNN50 (rs = -0.467, P = 0.038) and HF (rs = -0.444, P = 0.049). We did not observe significant correlation between the HRV indices during the GA-T and the muscle strength measures (HGS and QS). Conclusion: In conclusion, in women with RA, the longer the required to perform the GA-T the worse their parasympathetic modulation, sympathetic-vagal imbalance, and complexity of the autonomic nervous system were. Physical functioning level was also related to vagal modulation. Thus, the routine assessment of HRV integrated with GA-T may become an interesting means of monitoring this patient population, since these two tests are easy to perform and non-invasive.