Osteopenia in Patients with Glomerular Diseases Requiring Long-Term Corticosteroid Therapy

Background: Chronic corticosteroid (CS) use is associated with bone mass loss. Methods: Bone mineral density (BMD) was assessed in 72 patients (25 males/47 premenopausal females) with glomerular diseases, primary (n = 35) or secondary to systemic lupus erythematosus (n = 37) with normal renal function, who were taking CS, as prednisone and/or methylprednisolone, in doses ≧7.5 mg/day, for a period of at least 6 months. Cumulative dose and duration of prior CS therapy, as well as biochemical parameters and other factors contributing to bone loss were evaluated. Results: We found 37 (52%) patients with low BMD (29 with osteopenia and 8 with osteoporosis). The low BMD group presented a lower mean weight and body mass index (BMI) versus the normal BMD group (62 ± 15 vs. 70 ± 10 kg and 25 ± 4 vs. 27 ± 5, mean ± SD, p < 0.05). The estimated calcium intake was lower than 400 mg/day in all patients with low BMD, and they had taken furosemide as a concomitant drug for a longer mean period of time when compared to normal BMDpatients (30 ± 29 vs. 16 ± 27 months, p < 0.05). A higher mean number of pulses per patient and mean cumulative dose of methylprednisolone were observed in the low versus normal BMD group (7.7 ± 4.0 vs. 5.6 ± 4.0 pulses and 6.5 ± 3.9 vs. 3.9 ± 2.7 g, p < 0.05). Conclusions: These findings suggest a high frequency of osteopenia among young and premenopausal patients with glomerular diseases given long-term corticosteroid therapy. The lower BMI and calcium intake, as well as the concomitant furosemide use, might have contributed to such a bone loss. The higher number of pulse therapies leading to higher cumulative intravenous doses of corticosteroid mainly in lupus nephritis patients shows that pulse therapy may be deleterious to bone.