Ambulatory blood pressure in patients with rheumatoid arthritis: association with immune activation.

OBJECTIVE: The prevalence of hypertension, a major cardiovascular risk factor, is increased in patients with rheumatoid arthritis (RA) and may be driven by immune activation. The purpose of this study was to determine if ambulatory 24-hour blood pressure (BP) is elevated in RA versus control participants and associated with immune activation.

METHODS: We conducted a cross-sectional study of 46 patients with RA and 23 control participants. Participants wore an ambulatory BP monitor which obtained diurnal BP every 15-30 minutes and nocturnal BP every 30 minutes. Inflammatory mediators in plasma were measured using an inflammation proteomics panel. Differences in BP measurements were assessed by Mann-Whitney U, and association with inflammatory mediators was assessed by Spearman correlation.

RESULTS: Patients with RA and control participants had similar office BP, but ambulatory systolic BP measurements: 24-hour (median RA =121 mmHg versus control =116 mmHg, P=0.007), diurnal (RA =128 mmHg versus control =120 mmHg, P=0.003), and nocturnal (RA =112 mmHg versus control =103 mmHg, P=0.002) were higher in patients with RA. Patients with RA also had higher nocturnal diastolic BP (RA =63 mmHg versus control =57 mmHg, P=0.02), but other diastolic BP measurements were similar. Nocturnal BP dipping was less in RA (12%) compared to control participants (16%, P=0.02). In RA, higher 24-hour and nocturnal systolic BPs and less nocturnal dipping were strongly correlated with a wide range of inflammatory mediators.

CONCLUSION: Despite similar office measurements, 24-hour and nocturnal systolic BP measurements were higher in RA than control participants and were strongly associated with inflammation.