Lower Heart Rate Variability is Associated with High Disease Activity, Functional Disability and Inflammation in Rheumatoid Arthritis: A Cross-Sectional Study.

Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterised by persistent inflammation that negatively impacts cardiovascular health, often leading to cardiac autonomic neuropathy. Heart Rate Variability (HRV), a non-invasive measure, reveals compromised autonomic regulation in RA, as evidenced by reduced HRV and increased sympathetic control in RA. Despite existing evidence, the relationship between HRV and RA remains inconclusive, prompting this study to examine HRV in RA disease activity. Methods: Study involved 320 individuals with RA, aged ≥18 years, attending an outpatient clinic at a tertiary care multispecialty hospital in south India. Sociodemographic, clinical, and laboratory data, and HRV parameters, were obtained. RA disease-specific parameters such as Health-Related Quality of Life, Disease activity and Functional status were assessed using EuroQol-5D, Disease Activity Score-28 (DAS-28) and Health Assessment Questionnaire (HAQ) respectively. Spearman's correlation and linear regression analyses were performed to examine the association between HRV and RA disease-specific parameters. A statistical significance level of p<0.05 was considered. Result: We observed a significant negative correlation between HRV parameters and RA disease-specific parameters such as DAS-28, HAQ and Erythrocyte sedimentation rate. The linear regression analysis indicated that a lower Standard Deviation rate Beats Per Minute was linked to higher functional ability scores according to the HAQ Scale. Conclusion: Reduced HRV in individuals with RA is linked to higher disease activity, functional disability and inflammation. This underscores the significance of HRV as a potential tool for assessing cardiovascular autonomic function in RA patients, with implications for their management and prognosis.