Association between lipid levels and major adverse cardiovascular events in rheumatoid arthritis compared to non-rheumatoid arthritis patients.
OBJECTIVE
Lower levels of low-density lipoprotein (LDL) cholesterol may be associated with increased cardiovascular (CV) risk in rheumatoid arthritis (RA). This study was undertaken to determine whether the complex relationship between levels of LDL and high-density lipoprotein (HDL) cholesterol and CV risk is different in RA patients as compared to non-RA controls.


METHODS
Using data from a US health insurance plan (2003-2012), we conducted a cohort study that included patients with RA and non-RA control subjects matched with regard to age, sex, and index date. The nonlinearity of associations between lipid levels and incidence of major adverse CV events (MACE) was tested. We used multivariable Cox proportional hazards regression models to examine for an interaction between lipid levels and RA status in relation to the risk of MACE, after adjustment for CV risk factors.


RESULTS
In total, 16,085 RA patients and 48,499 non-RA controls were studied. The mean age was 52.6 years and 78.6% were women. The relationship between LDL cholesterol levels and incidence of MACE was nonlinear and similar between RA patients and non-RA controls (P for interaction = 0.72). No significant increase in CV risk was observed between the lowest quintile of LDL cholesterol levels (≤91.0 mg/dl) and the second, third, or fourth quintiles, whereas the highest quintile (>190.0 mg/dl) conveyed a 40% increase in risk of MACE (hazard ratio [HR] 1.40, 95% confidence interval [95% CI] 1.17-1.68). The relationship between HDL cholesterol levels and incidence of MACE was also nonlinear and similar between RA patients and non-RA controls (P for interaction = 0.39). Compared to the lowest quintile of HDL cholesterol levels, each successive quintile was associated with a reduced risk of MACE (HR 0.45, 95% CI 0.48-0.72 for lowest quintile [≤43.0 mg/dl] versus highest quintile [>71.0 mg/dl]).


CONCLUSIONS
The complex relationship between LDL cholesterol levels, HDL cholesterol levels, and risk of MACE was nonlinear in RA patients and also not statistically significantly different from that in an age- and sex-matched non-RA cohort.
Brigham and Women's Hospital, Boston, Massachusetts.
Katherine P
KP
Liao
Brigham and Women's Hospital, Boston, Massachusetts.
Jun
J
Liu
Brigham and Women's Hospital, Boston, Massachusetts.
Bing
B
Lu
Brigham and Women's Hospital, Boston, Massachusetts.
Daniel H
DH
Solomon
Brigham and Women's Hospital, Boston, Massachusetts.
Seoyoung C
SC
Kim
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000601:surgery; D016022:Case-Control Studies; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000601:surgery; D050171:Dyslipidemias / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000601:surgery; D062645:Percutaneous Coronary Intervention / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D020521:Stroke / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides