Boomsma, M.M., Stegeman, C.A., Kramer, A.B., Karsijns, M., Piers, D.A., and Cohen Tervaert, J.W.
Byline: M. M. Boomsma (1), C. A. Stegeman (2), A. B. Kramer (3), M. Karsijns (3), D. A. Piers (4), J. W. Cohen Tervaert (5) Keywords: Key words:Bone mineral density -- Osteoporosis -- Steroids -- Vasculitis Abstract: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a relapsing-remitting disease, which is treated with corticosteroids (CS) in combination with cyclophosphamide. One of the major side-effects of this treatment is osteoporosis, which may result in the increased occurrence of fractures. In the present study we measured the prevalence of reduced bone mineral density (BMD) in a cross-sectional cohort of patients and correlated BMD findings with cumulative doses of CS and/or cyclophosphamide. BMD was measured by dual-energy X-ray absorptiometry (DXA) of the lumbar spine, radius and proximal femur between January 1998 and December 1999. Cumulative doses of CS and cyclophosphamide were calculated by chart review. Ninety-nine consecutive patients (48 men, 51 women) aged 55 +- 16 years (mean +- SD) were studied 50 months (median range 0--400 months) after a diagnosis of ANCA-associated vasculitis had been made. Sixty-nine patients were treated with 10.7 g (median cumulative dose range 0.4--67.2g) of CS, and 88 patients were treated with 34.1 g (median cumulative dose range 0.8--324.3g) of cyclophosphamide. Fifty-seven percent of the patients had osteopenia (T-score: --1 to --2.5 SD), and 21% had osteoporosis (T-score: < -2.5 SD) at least at one site. Thirty-four of 37 (92%) postmenopausal women, 9 of 14 (64%) premenopausal women, and 34 of 48 (71%) men had either osteopenia or osteoporosis. The mean age- and sex-adjusted BMD (Z-score) of the proximal femur in men was found to be significantly lower than zero. Cumulative dose of CS therapy showed an inverse relation with Z-scores at the lumbar spine (p= 0.035) and proximal femur (p=0.011). Cumulative dose of cyclophosphamide was not correlated with Z-scores. Osteopenia and osteoporosis are thus frequently observed in patients with ANCA-associated vasculities. However, only in men is the mean Z-score significantly lower than zero. Cumulative dose of CS therapy is significantly associated with bone loss at the spine and femur. Author Affiliation: (1) Division of Clinical Immunology, NL (2) Division of Nephrology, NL (3) Medical Student, NL (4) Department of Nuclear Medicine, University Hospital Groningen, Groningen , NL (5) Division of Clinical Immunology, University Hospital Maastricht, Maastricht, The Netherlands, NL Article note: Received: 26 March 2001 / Accepted: 1 August 2001