The lipid paradox is also present in early axial spondyloarthritis: results from the Swedish part of the SPondyloArthritis Caught Early (SPACE) cohort

Abstract

Objective: Inverse associations between systemic inflammation and cholesterol (‘the lipid paradox’) have beenreported in rheumatoid arthritis (RA) and, in established axial spondyloarthritis (axSpA), but little is known aboutthis relationship in early axSpA, which is the focus of the present study.Method: In the Swedish part of the SPondyloArthritis Caught Early (SPACE) cohort (patients with chronic back painfor ≥3 months, ≤2 years; age at onset <45 years), serum levels of total cholesterol (TC) and apolipoproteins ApoA1and ApoB were measured at inclusion, together with parameters reflecting inflammatory disease activity [C-reactiveprotein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and sacroiliitis by magnetic resonanceimaging (MRI) following Assessment of SpondyloArthritis international Society (ASAS) criteria]. All patientsincluded in the analysis either had axSpA based on a high physician’s level of confidence or fulfilled the ASAScriteria for axSpA. Associations between lipids/lipoproteins and inflammation were assessed using multivariable linearregression models.Results: In the 64 patients included, there were inverse associations for CRP with TC, ApoA1, and ApoB in age–sex-adjusted models. The negative associations with CRP remained significant for TC and ApoB in multivariable modelsadjusted for age, sex, BASDAI, and current smoking (p = 0.048). There were no significant associations for the lipidparameters with BASDAI or inflammation on MRI of the sacroiliac joints.Conclusion: Inverse associations between systemic inflammation and lipids, particularly TC and ApoB, are present inearly axSpA, similar to those shown for other inflammatory joint diseases. These patterns must be considered whenincluding lipids in the evaluation of cardiovascular disease risk.