Homocysteine, bone mineral density, and fracture risk over 2 years of followup in women with and without systemic lupus erythematosus

Abstract

Objective: To examine the relationship of baseline homocysteine levels with bone mineral density (BMD) and incidence of fractures over 2 years in women with and without systemic lupus erythematosus (SLE).

Methods: Women with SLE (n = 100) and without SLE (n = 100) were matched according to age (+/- 5 yrs), race, and menopausal status. Data were collected from 1997 to 2004, including hip, lumbar spine (L-spine), and distal forearm BMD, serum homocysteine levels, and a self-administered questionnaire on osteoporosis risk factors, medications and symptomatic fractures at baseline and 2-year followup. Analyses were performed to compare homocysteine levels, BMD, and incident fractures and to evaluate the relationship of homocysteine with BMD and incident fractures in both groups.

Results: Mean homocysteine +/- SD was higher (p < 0.001) in women with SLE (9.88 +/- 3.8 micromol/l) than in women without SLE (7.98 +/- 2.6 micromol/l). Women with SLE had significantly lower L-spine BMD Z-scores, while hip BMD Z-scores and distal forearm BMD T-scores were nonsignificantly lower than in women without SLE. No significant correlations were observed between homocysteine and BMD in either group. Thirteen women with SLE experienced new fractures, while 4 women without SLE had new fractures over 2 years (p = 0.035); however, there was no association between homocysteine levels and incident fractures in either group.

Conclusion: Women with SLE had significantly greater baseline homocysteine, lower L-spine BMD, and more new fractures over 2 years, compared with women without SLE. Homocysteine levels were not significantly associated with BMD and did not predict new fractures in women with or without SLE over 2 years.