Objective: To quantify the relationship between arterial stiffness and cumulative inflammatory burden in patients with RA.
Methods: We recruited RA patients without overt arterial disease aged 40-65 years, attending hospital rheumatology outpatient clinics. Standardized research nurse assessment included blood pressure (BP), pulse wave analysis (PWA, SphygmoCor), BMI, fasting blood sample (lipids, glucose, RF and ESR), patient questionnaire (smoking, alcohol, diet, exercise, family history of premature coronary heart disease and Stanford HAQ), current medication and medical record review. Cumulative inflammatory burden was measured as ESR area-under-the-curve (ESR-years) extracted from medical records. Arterial stiffness was measured using PWA [aortic augmentation index (AIX@75)]. Multiple linear regression was used to adjust for age, sex and nine other cardiovascular risk factors.
Results: We recruited 114 RA patients (mean age 54 years, female 81%, current DMARD 90%, current NSAID 70%, ACR criteria 56%) comprising 1040 RA person-years. Cholesterol, glucose and BMI were similar in women and men. Women had a longer duration of arthritis (10 vs 7 years) and were more likely to be seropositive (85 vs 71%). BP, smoking and alcohol consumption were lower for women. On fully adjusted analysis, an increase of 100 ESR-years was associated with an increase in AIX@75 of 0.51 (95% CI 0.13, 0.88). On fully adjusted analysis restricted to women the increase was 0.43 (95% CI 0.01, 0.85).
Conclusions: In RA patients free of overt arterial disease, a dose-response relationship exists between cumulative inflammatory burden and arterial stiffness. This relationship is independent of established CV risk factors.