Rheumatoid arthritis and autonomic function (1132.10)

Abstract

Rheumatoid arthritis (RA) is an inflammatory disorder associated with increased cardiovascular mortality. We sought to determine whether muscle sympathetic nerve activity (MSNA) is heightened, and cardiac baroreflex sensitivity (cBRS) is reduced in patients with RA. Whilst resting supine, blood pressure (BP; Portapres), heart rate (HR; ECG) and MSNA (microneurography) were continuously monitored in 7 chronic RA patients (5 men, 56±4 yr, 28±1 kg/m²; mean±SE), 7 healthy controls (HC: 5 men, 52±5 yr, 26±1 kg/m²) and 7 patients with hypertension as ‘disease’ controls (DC: 5 men, 54±5 yr, 28±1 kg/m²). MSNA burst frequency and spontaneous cardiac baroreflex sensitivity (sequence technique, systolic BP‐RR interval) were determined. Mean BP (p=0.001) and HR (p=0.014) were lower in HC group (88±5 mmHg, 55±2 bpm) than RA patients (106±2 mmHg, 70±3 bpm) and the DC group (116±6 mmHg, 63±4 bpm). MSNA burst frequency tended to be higher in RA patients and the DC group (34±4, 37±3 and 26±3 bursts/min in RA, DC, HC; P=0.066), whilst cBRS was reduced in RA (7.6±2.0, 10.0±3.1 and 16.7±2.1 ms/mmHg in RA, DC, HC; P<0.05 RA vs. HC and DC). These preliminary findings support the existence of an imbalance in autonomic neural control of the heart and peripheral vasculature in patients with RA.Grant Funding Source: Supported by Arthritis Research UK