Objective: Systemic lupus erythematosus (SLE) is characterized by a markedly elevated risk for coronary heart disease (CHD), the exact pathogenesis of which is unknown. In particular, the causal roles of corticosteroid therapy and SLE disease activity, and whether their putative effects are mediated through conventional risk factors, remain unclear.
Methods: Data abstracted retrospectively from the charts at 11,359 clinic visits for 310 patients with SLE to the Montreal General Hospital were used to investigate the associations of recent corticosteroid dose and recent Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score with 8 CHD risk factors (total serum cholesterol, high-density lipoprotein [HDL] cholesterol, low-density lipoprotein cholesterol, apolipoprotein B [Apo B], triglycerides, systolic blood pressure [BP], body mass index, and blood glucose) and the aggregate estimate of 2-year CHD risk. Separate multivariable linear regression models estimated the mutually-adjusted effects of average daily corticosteroid dose and average SLEDAI score within the past year on the current level of each risk factor while adjusting for age, sex, cumulative damage score, disease duration, and, where appropriate, use of relevant medications.
Results: Higher past-year corticosteroid dose was independently associated with significantly higher overall 2-year CHD risk and with higher levels of all 8 individual risk factors. Higher past-year lupus disease activity was independently associated with higher overall 2-year CHD risk, lower HDL cholesterol, and higher values of systolic BP, Apo B, triglycerides, and blood glucose.
Conclusion: In SLE, both recent use of corticosteroids and recent lupus activity are independently associated with higher values of several well-recognized CHD risk factors and overall 2-year CHD risk.