Objectives: To compare lipid profiles in patients with rheumatoid arthritis (RA) and non-RA subjects during the 5 years before and 5 years after RA incidence/index date.
Methods: Lipid measures were abstracted in a population-based incident cohort of RA patients (1987 ACR criteria) first diagnosed between 1/1/1988 and 1/1/2008 and in non-RA subjects. Random effects models adjusting for age, sex and calendar year were used to examine trends in lipid profiles, accounting for multiple measurements per subject.
Results: Study population included a cohort of 577 RA patients (a total of 3,088 lipid measurements) and 540 non-RA subjects (a total of 3,048 lipid measurements). There were significant decreases in total [TCh] and low-density cholesterol [LDL] levels in the RA cohort during the 5 years before RA, compared to the non-RA cohort (p<0.001). Trends in other lipid measures (triglycerides and high-density cholesterol) were similar in RA and non-RA cohorts during the 5 years before and 5 years after RA incidence/index date. During the 5 years before RA incidence/index date, the proportion of RA patients with elevated TCh or LDL measures, but not with abnormal HDL and TG measures, significantly decreased compared to non-RA subjects. Lipid-lowering drugs (statins in particular) were less often (p=0.02) prescribed to RA patients than to non-RA subjects.
Conclusion: TCh and LDL levels and the prevalence of abnormal TCh or LDL measures decreased significantly during the 5 years before RA incidence/index date in RA patients as compared to non-RA cohort. These trends in lipid profile in RA are unlikely to be solely due to lipid-lowering therapy.