MADRID – High baseline disease activity and serum C-reactive protein levels may be a means of predicting which patients with spondyloarthropathy are likely to develop cardiovascular disease.
Both were linked to arterial stiffness, a surrogate marker for heart disease, in a 5-year follow-up study of 103 hospital-recruited patients with ankylosing spondylitis (Ann. Rheum. Dis 2013;72[Suppls3]:125).
"Reducing disease activity may [therefore] be a viable way of reducing excess cardiovascular disease [CVD] in ankylosing spondylitis [AS]," study investigator Dr. Inger Jorid Berg said at the annual European Congress of Rheumatology.
Baseline disease severity was measured with the ankylosing spondylitis disease activity score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). However, only ASDAS predicted the development of increased arterial stiffness from high baseline disease activity.
"Several studies have shown that patients with ankylosing spondylitis have [an] increased [risk] of cardiovascular disease," noted Dr. Berg, a consultant rheumatologist at Diakonhjemmet Hospital in Oslo. This includes atherosclerotic CVD, she observed, which previous research has linked to having a high ASDAS.
The present investigation explored whether high baseline ASDAS could be used to predict increased arterial stiffness as measured with the Augmentation Index (AIx). The investigators measured arterial stiffness using the SphygmoCor apparatus, a noninvasive system that involves placement of a probe at the radial artery.
Patients included in the study had AS confirmed via modified New York criteria and had undergone assessments in 2003 and again in 2008-2009. The assessments included clinical examinations and questionnaires to assess baseline disease severity and blood tests to measure C-reactive protein (CRP) levels and the erythrocyte sedimentation rate (ESR).
At the baseline assessment in 2003, the patients (56% men) had a mean age of 48 years, and a mean body mass index of 24.4 kg/m2. A quarter of the patients were smokers. Their mean ASDAS was 2.5 and their mean BASDAI was 4.1, indicating moderate disease activity. There were only a few known cardiovascular comorbidities present, which included hypertension (5%) and diabetes (3%), although there were more patients with comorbidities at the later assessment. Most (83%) patients were taking nonsteroidal antiinflammatory drugs. Another 17% were using disease-modifying antirheumatic drugs, and very few (2%) were using tumor necrosis factor inhibitors.
"There was a clear trend in increasing CRP values, ESR values, and ASDAS," Dr. Berg said. This was significant for CRP (P = .004) and ASDAS (P = .01), and borderline significant for ESR (P = .05).
Multivariate analysis showed that CRP and ASDAS were independent predictors of increasing AIx, with an odds ratio of 2.09 (P = .02) for the latter.
"The strengths of this study are its longitudinal design and a representative cohort reflecting a range of disease activity," Dr. Berg observed. "Limitations are the low number of patients and that there might be a selection bias when inviting patients to examinations." Traditional risk factors were also not recorded during the 2003 assessment, so the effect of these variables could not be evaluated.
What these data show, however, are that inflammation signaled by elevated CRP and high disease activity measured by ASDAS predict future arterial stiffness, indicating that both are risk factors of CVD in AS. As such, better control of both of these parameters might be a way to reduce risk for CVD in this patient population.
Dr. Berg did not have any conflicts of interest to disclose.