Coronary flow reserve and asymmetric dimethylarginine levels : new measurements for identifying subclinical atherosclerosis in patients with psoriatic arthritis

OBJECTIVE: To identify the presence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA) and healthy controls using intima-media thickness (IMT), coronary flow reserve (CFR), and the plasma concentration of asymmetric dimethylarginine (ADMA), to evaluate the correlations among ADMA, IMT, and CFR. METHODS: The study involved 22 patients who fulfilled the ClASsification of Psoriatic ARthritis study group criteria for PsA and a cohort of 35 healthy controls with no history or current signs of coronary artery disease (CAD). Common carotid IMT was measured using high-resolution B-mode ultrasonography. Dipyridamole transthoracic stress echocardiography was used to evaluate CFR. Blood samples were obtained to assess ADMA levels. The clinical manifestations were recorded. All patients were treated with disease-modifying antirheumatic drug, but none had received any biological or steroid therapy. RESULTS: Plasma ADMA levels were significantly higher in the patients with PsA (0.71 ± 0.07 μmol/l vs 0.48 ± 0.07 μmol/l; p = 0.00) and CFR was significantly reduced in that group (2.86 ± 0.70 vs 3.3 ± 0.43; p < 0.01) compared to controls. Common carotid IMT was greater in the patients with PsA, but the difference was not significant (0.64 ± 0.26 mm vs 0.62 ± 0.5 mm; p = 0.65). There was a significant correlation between CFR and plasma ADMA levels in the PsA group (R = 0.28; p < 0.01), but no correlation between plasma ADMA levels and IMT (R = 0.02; p = 0.32), Disease Activity Score 28 (p = 0.52), or Psoriasis Area and Severity Index (p = 0.98). CONCLUSION: Our patients with PsA showed a profile of subclinical atherosclerosis. ADMA may be a useful marker of endothelial dysfunction in PsA.