Effect independent of steroid use: disease activity may deplete BMD in lupus

OB/GYN News, June 15, 2004 by Jeff Evans

NEW YORK -- Systemic lupus erythematosus itself is a risk factor for low bone mineral density, independent of the use of bone mineral-depleting corticosteroids. Dr. Chin Lee said at the Seventh International Congress on SLE and Related Conditions.

Now that mortality rates associated with lupus have improved, "greater attention has been focused on trying to prevent long-term complications in this disease," said Dr. Lee of the division of rheumatology at Northwestern University, Chicago.

Previous investigations into lupus and low bone mineral density (BMD) did not adequately control for corticosteroid use.

The investigators analyzed data from a cross-sectional, observational study on bone health in African Americans and whites conducted during 1996-2002. In their posthoc analysis, a higher cumulative disease damage associated with lupus was associated with lower BMD, even after controlling for corticosteroid use.

The analysis involved stratifying 293 women with lupus into four groups: 136 corticosteroid users with Systemic Lupus International Collaborating Clinics cumulative disease damage index (SLICC-DI) scores of 1 or higher; 21 corticosteroid nonusers with SLICC-DI scores of 1 or higher; 93 corticosteroid users with SLICC-DI scores of 0; and 43 patients who had never used corticosteroids and who had SLICC-DI scores of 0.

The women with higher cumulative lupus disease damage who used corticosteroids had significantly lower BMD in the spine than did women with low cumulative disease damage who used corticosteroids. Likewise, BMD in both the hip and the spine was lower among women with high rates of disease damage and who used corticosteroids compared with those women with lower cumulative disease damage who had never used corticosteroids. The trend was significant both before and after adjustment for clinical and demographic variables.

The two groups with high cumulative disease damage, however, did not have any significant differences in BMD in the hip, spine, or distal forearm. They also tended to be older, had longer disease durations, and had higher body mass indexes compared with women who had lower cumulative disease damage.

The researchers did not analyze the dosage or duration of corticosteroid use.

Low BMD associated with either the disease activity of lupus or the use of corticosteroids may be amenable to preventive measures and treatments. In a poster presented at the congress. Dr. Michelle Petri of Johns Hopkins University, Baltimore, and her associates reported significant increases of BMD that averaged 1.7% in the lumbar spine and 2% in the hip among 24 women with lupus who took the adrenal androgen prasterone (also known as dehydroepiandrosterone or DHEA), compared with 31 women who received place bo. The women in the placebo group lost an average of 1.1% of their BMD in the lumbar spine and 0.3% in the hip.

The randomized, double-blind, 1-year study of BMD was part of a larger, multicenter study analyzing prasterone's effect on overall SLE disease activity when given orally at 200 mg per day.

All the patients who had BMD assessments at baseline and at their last study visit received 10 mg or less of prednisone per day for 6 or more months before they entered the study: they continued to receive corticosteroids and other common SLE medications throughout the study.

Side effects such as acne and hirsutism occurred significantly more often among patients taking the prasterone.

Dr. Petri and her colleagues plan to evaluate the efficacy and safety of prasterone on BMD in women with lupus as a primary end point in a future 6-month trial.

BY JEFF EVANS

Senior Writer