Background:Nocturnal hypertension (HTN) and non-dipping profile are important predictors of adverse cardiovascular (CV) outcomes. Their associations with subclinical vascular damage in rheumatoid arthritis (RA) are still a matter of investigation. It was shown that 10-year atherosclerotic CV disease risk (rASCVD) may be more accurate in CV risk prediction in RA than SCORE. Associations of impaired 24-h BP phenotypes with CV risk in RA are not well-studied yet.Objectives:To assess dipping patterns and nighttime systolic blood pressure (SBPn) and their associations with arterial stiffness and CV risk assessed by rASCVD in patients with RA.Methods:Study group included 90 patients with RA (females 78.7%, age 59.5±14.2 years, HTN 64%, median (med) HTN duration 6.4 years, RA duration – 7.2 years, seropositive RA 66%, mean DAS-28(CRP) 3.8±1.0) and control group (45 patients matched by gender, age and risk factors). All patients with HTN received antihypertensive therapy. Office BP was measured with a validated oscillometric device, 24-hour ABPM was performed with BPLab Vasotens, carotid-femoral PWV was assessed by applanation tonometry. 3 groups were formed after adjustment of dipping state by SBPn: dippers (G1), non-dippers with SBPn<120 mmHg (G2), non-dippers with SBPn≥120 (G3). CV risk in RA group was calculated as 10-year rASCVD. Risk≥7.5% was considered as high. p<0.05 was considered significant.Results:Median rASCVD was 6.3%. Rate of BP control was 60% in RA and 66% in the controls (p=0.5). Patients with RA vs controls had higher mean SBPn (124±16 vs 110±8 mmHg, p=0.003), lower diurnal index (DI) (med 3.8 vs 8.1%, p=0.02), higher rate of night HTN (49.6 vs 12.2% (p=0.0002). The RA and control groups didn`t differ by dipping patterns, although RA patients more often had non-dipping profile (DI <10%): 83.9 vs 61.3%, (p=0.02). RA patients with SBPn ≥120 mmHg had higher age (63.7±12.5 vs 52.9±14.5 years), office SBP (143±17 vs 122±13 mmHg), HTN duration (med 5.4 vs 0.5 years), PWV (10.3±3.0 vs 7.9±2.5 m/s) and rASCVD (12 vs 3.4%), p<0.001 for trend. Analysis in hypertensive RA group confirmed significant differences in PWV (11.3±3.1 vs 9.1±3.2 m/s, p=0.02) and rASCVD (med 13.5 vs 10.5%, p=0.045). Patients with DI<10% had higher age (60.9±13.8 vs 54.3±11 years, p=0.04) and rASCVD (med 8.5 vs 3.1%, p=0.02). Patients with rASCVD ≥7.5% compared to <7.5% had higher SBPn (133±11 vs 112±8 mmHg), lower median DI (0 vs 6%), more often had masked HTN (43 vs 16%) and night HTN (48 vs 16%), p<0.01 for trend. SBPn significantly correlated with age (r=0.6), office SBP (r=0.5) and DBP (r=0.4), PWV (r=0.6), rASCVD (r=0.6); non-dipping pattern – with age (r=0.2), and rASCVD (r=0.3). After adjustment by SBPn, no differences were observed between G2 and G3. Patients in G3 vs G1 had higher PWV (10.4±3.1 vs 7.6±1.7 m/s, p=0.004), CRP (med 15.7 vs 7.8 mg/l, p=0.03), rASCVD (med 12.8 vs 3.1%) (p<0.001); in G3 vs G2 – higher PWV (10.8±3.1 vs 8.2±2.3 m/s), rASCVD (med 12.8 vs 2.7%) and ESR (med 45 vs 21 mm/h, p<0.01 for trend).Conclusion:Patients with RA had higher incidence of non-dipping pattern and SBPn elevation. Combination of high SBPn and non-dipping was associated with higher arterial stiffness and CV risk – this may be mediated by inflammation. Higher CV risk was associated with masked and night HTN. This may help in defining indications for ABPM in this population.