Pediatric Rheumatology Online Journal → July 2003 → Childhood Lupus→ Clinical Presentation, course and Outcomes → Abstract #93
                                                                August 2003 → Bone → Osteoporosis → Abstract #93

INCIDENCE OF OSTEOPOROSIS IN PEDIATRIC SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

S. Compeyrot, S. Benseler, P. Tyrrell, T. Sarkissian, E. Silverman

¹Rheumatology, Hospital for Sick Children, Toronto, ON, Canada

SLE is a multi-organ auto-immune disease. 15-20% of SLE patients present before the age of 16. Previous studies suggested that children with SLE have a significant decrease in bone mineral density (BMD) and in peak bone mass which was correlated with the cumulative dose of steroid.
[underline>Objectives[/underline>: To correlate disease activity, steroid administration and BMD in patients with pediatric SLE.
[underline>Methods[/underline>: We retrospectively reviewed a cohort of 145 patients diagnosed at the HSC with pediatric SLE between 1990 and 2002. 49 (33.8%) patients had a dual-energy X-absorptiometry (DEXA) scan. The BMD results were corrected for bone age and are expressed in Z-score for lumbar spine (abnormal -1) and in percentage for hip (abnormal 90%). Data for disease activity (SLEDAI), steroid therapy (cumulative dose, duration of treatment and average dose within the last 3 months) osteoporosis complications (fracture, vertebral collapse) and puberty status were collected at the time of the DEXA. The correlation was tested using Spearman test.
[underline>Results[/underline>: The 49 patients with DEXA data were 34 female (69.4%) and 15 male (30.6%). Mean age was 14.7 years old (6-21). Mean disease duration was 3 years (0-10). One patient had a vertebral fracture. All patients had received steroid treatment with a mean duration of treatment of 33 months (0-123). The mean cumulative dose was 406 mg/kg (0-1500). Disease activity was assessed in 40 patients with a mean SLEDAI of 4.5 (0-19). 26 patients (53%) had a decreased BMD at the lumbar spine or hip. The mean BMD was -1.15 (-3.9-1.5) at the lumbar spine and 94.1% at hip (67%-124%). Decreased BMD was statistically significantly correlated with disease duration, duration of steroid treatment and cumulative dose of steroids but not with disease activity.
[underline>Conclusion[/underline>: This study showed that osteoporosis is a long-term complication of pediatric SLE. As most patients require long-term steroid treatment, early detection and treatment of abnormal BMD may reverse loss of bone mass prior to the development of osteoporosis and fracture.