Background Patients with rheumatoid arthritis (RA) suffer from increased mortality due to cardiovascular disease (CVD) (1). Aerobic capacity (VO2 max) is inversely and strongly related to cardiovascular disease in the general population (2). RA patients have shown very low levels of VO2 max compared to normative values of healthy adults (3), which may be of importance for the increased CVD incidence in RA.
Objectives To analyse the change of VO2 max over time from disease onset and associated potential risk- and health factors in patients with RA.
Methods 25 patients (20 f/ 5 m), diagnosed with RA 1995–2002 were tested at disease onset (<12 months from symptom onset) and after a mean of 16.2 years. Applied measurements were: sub-maximal ergometer test for VO2 max, functional ability, joint- and muscle function, self-efficacy, ESR, CRP, number of tender and swollen joints and patient's global health. At follow-up, the risk of CVD was measured as blood levels of lipids, insulin and glucose, Body mass index (BMI), waist circumference and body composition measured by Dual-energy X-ray absorbtiometry (DXA). Pulse wave analysis (PWA), was used to register early endothelial dysfunction, arterial stiffness and systolic blood pressure in aorta besides peripheral blood pressure. Carotid Intima-Media Thickness (IMT) was measured by ultrasonography. Additionally, Fatigue Severity Scale was used at follow-up.
Results All measures reflecting disease activity decreased significantly during the follow-up period. VO2 max was (median (IQR)) 32.3 (14.2) ml O2/kg x min at disease onset, and 33,2 (10.5) at follow-up (p>0.05). Aerobic capacity at inclusion was associated with follow-up values for age (r=-.469, p=.018), VO2 max (r=.557, p=.004), BMI (r=-.401, p=.047), body weight (r=-.409, p=.043), waist circumference (r=-.498, p=.011) and periferal pulse pressure (r=-.415, p=.039). Variables at disease onset associated with VO2 max at follow-up were VO2 max (r=.557, p=.004) and self-efficacy for function, (r=.544, p=.029).
Conclusions In patients with RA followed for 16 years from disease onset, VO2 max was maintained. High aerobic capacity at disease onset was associated with favourable measures of VO2 max and body weight at follow-up. The variables at disease onset that best correlated with a high VO2 max at follow-up were high VO2 max and self-efficacy for function. Our results may be important for preventive strategies in RA.
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Disclosure of Interest None declared