The apoB/apoA1 ratio predicts future cardiovascular events in patients with rheumatoid arthritis

Abstract

Objectives: Patients with rheumatoid arthritis (RA) have increased mortality and morbidity due to cardiovascular disease (CVD). A high apolipoprotein (apo)B/apoA1 ratio is known to predict cardiovascular events (CVEs) in the population. apoA1 has, besides anti-atherogenic effects, anti-inflammatory properties. The importance of apolipoproteins in the development of CVEs, in the context of lipids, haemostatic factors, and inflammation, was evaluated over 18 years in patients with RA.

Method: Seventy-four patients with inflammatory active RA (61 females/13 males, mean age 63.6 years, disease duration 22.1 years) had been previously investigated in a study of haemostatic factors [tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI)-1, von Willebrand factor (vWF)], lipids (cholesterol and triglycerides), apolipoproteins (apoA1 and apoB), lipoprotein(a) [Lp(a)], and markers of inflammation [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and haptoglobin]. After 18 years, the first CVE during follow-up and the presence of traditional CV risk factors, extra-articular disease, and pharmacological treatment were registered. Cox proportional hazards regression was used to identify predictors of a new CVE.

Results: A new CVE (n = 34) was predicted by the apoB/apoA1 ratio (p < 0.01), the triglyceride level (p < 0.01), PAI-1 (p < 0.01) and tPA (p < 0.01) activities, vWF (p < 0.001), ESR (< 0.001), CRP (< 0.05), and haptoglobin (p < 0.05). apoA1 (p = 0.056) and apoB (p < 0.05) correlated weakly and inversely with haptoglobin and CRP, respectively. In a multiple Cox regression model, adjusted for gender and previous CVD, the apoB/apoA1 ratio significantly predicted a new CVE, as did vWF, PAI-1, and ESR.

Conclusions: The apoB/apoA1 ratio was a good predictor of CVE during 18 years of follow-up in patients with active RA. Apolipoproteins correlated negatively with inflammation.

Acknowledgements

This work was supported by grants from the Swedish Rheumatism Association, the Visare Norr, Norrlandstingens regionförbund (Northern County Councils), the Medical Faculty of Umeå University, the Swedish Heart–Lung Foundation, and the Swedish national project ‘COMBINE’.