To evaluate risk factors of sub-clinical atherosclerosis in a pediatric SLE population.
A prospective multicenter cohort of 221 patients underwent baseline measurements of carotid intima medial thickening (CIMT) as part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) trial. SLE disease measures, medications, and traditional risk factors for atherosclerosis were assessed. A standardized protocol was used to assess thickness of the bilateral common carotids and mean maximal IMT of 12 segments. Univariable analysis identified potential associations with CIMT that were examined in multivariable linear regression modeling.
Based on mean-mean common or mean-max CIMT as the dependent variable, univariable analysis showed significant associations with increased CIMT: increasing age, longer SLE duration, minority status, higher BMI, male sex, increased creatinine clearance, higher Lp(a), proteinuria, azathioprine use, and prednisone dose. Azathioprine use (P=0.005 for mean-mean common; P=0.102 for mean-max model) and male sex (P< 0.001) were both associated with increases in mean-max CIMT. Moderate dose prednisone (0.15–0.4 mg/kg/day) was associated with decreases in mean-max CIMT (P=0.024) while high or low dose prednisone was associated with mean-mean common CIMT (P=0.021) or mean-max CIMT (P=0.064), respectively. BMI (P<0.001) and creatinine clearance (P=0.031), remained associated with increased mean-mean common CIMT, while increasing age (P<0.001) and increasing Lp(a) (P=0.005) were associated with increased mean-max CIMT.
Traditional as well as non-traditional risk factors are associated with increased CIMT in pediatric SLE patients in this cohort. Azathioprine treatment was associated with increased CIMT. The relationship of CIMT with prednisone dose may not be linear.