Sympathetic Overactivity and Increased Cardiovascular Responses to Muscle Metaboreflex Activation in Post‐menopausal Women with Rheumatoid Arthritis

Abstract

AIMTo investigate the effects of rheumatoid arthritis (RA) on resting cardiovascular autonomic function and on pressor and sympathetic responses to muscle mechanoreflex and metaboreflex activation.METHODSThirty‐seven post‐menoupausal women with RA (60±7 yrs, 27.1±4.9 kg/m2, 19.2±4.7 ml.kg−1.min−1) and 9 matched controls (CON) (59±7 yrs, 26.1±3.3 kg/m2, 22.7±2.3 ml.kg−1.min−1) took part on this cross‐sectional study. Assessments included resting mean arterial pressure (MAP), heart rate (HR), muscle sympathetic nerve activity (MSNA, bursts frequency and incidence), heart rate variability (HRV), and spontaneous baroreflex sensitivity (BRS, gain and baroreflex effectiveness index [BEI]). In addition, MAP, HR, and MSNA in response to muscle mechanoreflex (passive stretching of posterior thigh) and muscle metaboreflex (post‐exercise circulatory occlusion [PECO] following static knee extension at 30% of maximal voluntary contraction) were assessed. Comparison between RA and CON was performed using a Student's t test. RA participants were grouped according to disease activity (Remission – DAS28 < 2.6; Low‐to‐moderate activity – DAS28 ≥ 2.6) and duration (Group 1 < 8.5 years; Group 2 = 8.5–17.5 years; Group 3 = 17.15–27.75 years; Group 4 ≥ 27.75 years), and results were compared using One‐way ANOVA. Associations between main outcomes and clinical characteristics (i.e., inflammation, disease activity, disease duration, quality of life, and pain) were performed using a Pearson product‐moment correlation coefficient. Significance level was set at p < 0.05.RESULTSParticipants with RA presented greater MSNA (48±11 vs. 31±15 bursts.min−1, p<0.01) and reduced BRS (BEI = 0.32±0.18 vs. 0.47±0.13, p=0.01) at rest when compared with CON. Increases in MAP, HR and MSNA during PECO were significantly greater in RA than CON (all p<0.05). Additional analyses showed that MAP responses to muscle metaboreflex activation were greater in RA patients in low‐to‐moderate active disease compared with those in remission (18±11 vs. 11±8 mmHg, p=0.05), and in those with longer disease duration (Group 4: 25±7; Group 1: 10±8 mmHg; p <0.01). Pressor responses to metaboreflex activation were positively correlated with C‐reactive protein levels (r=0.56, p=0.03). Responses to mechanoreflex activation were not different between groups.CONCLUSIONPatients with RA presented baroreflex impairment and sympathetic overactivity at rest and augmented cardiovascular responses to the activation of muscle metaboreflex. These abnormal neural and cardiovascular responses might contribute to the increase in cardiovascular risk in RA.Support or Funding InformationFAPESP 2016/23319‐0This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.