title: Prevalence of reduced bone mineral density in patients with anti-neutrophil cytoplasmic antibody associated vasculitis and the role of immunosuppressive therapy: a cross-sectional study.
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 0.4-67.2 g) of CS, and 88 patients were treated with 34.1 g (median cumulative dose; range 0.8-324.3 g) 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.
authors.affiliation: Division of Clinical Immunology, University Hospital Groningen, The Netherlands. M.M.Boomsma@Int.Azg.NL
authors.forename: M M
authors.initials: MM
authors.lastname: Boomsma
authors.forename: C A
authors.initials: CA
authors.lastname: Stegeman
authors.forename: A B
authors.initials: AB
authors.lastname: Kramer
authors.forename: M
authors.initials: M
authors.lastname: Karsijns
authors.forename: D A
authors.initials: DA
authors.lastname: Piers
authors.forename: J W Cohen
authors.initials: JW
authors.lastname: Tervaert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis*; D015519:Bone Density / Q000187:drug effects; D003430:Cross-Sectional Studies; D003520:Cyclophosphamide / Q000009:adverse effects / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000139:chemically induced / Q000209:etiology* / Q000503:physiopathology; D015663:Osteoporosis, Postmenopausal / Q000139:chemically induced / Q000209:etiology / Q000503:physiopathology; D014657:Vasculitis / Q000150:complications* / Q000188:drug therapy / Q000276:immunology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D003520:Cyclophosphamide