Effect of Bisphosphonate and Active Vitamin D Analog on Glucocorticoid-induced Osteoporosis in Patients with IgA Nephropathy: A Retrospective Observational Study.

Few studies on glucocorticoid (GC)-induced osteoporosis exist in IgA nephropathy (IgAN). Here we aimed to compare the effects of bisphosphonate (Bis) and active vitamin D analog (Vit. D) in maintaining bone mineral density (BMD) in patients with IgAN. This study is a retrospective observational one. Between April 2007 and December 2014, a total of 127 patients with IgAN received GC treatment at Kobe University Hospital. Among them, we measured the BMD of 48 patients with a mean age of approximately 30 years, before and after GC treatment. The %ΔBMD of the lumber spine increased in the Bis group (1.6% ± 2.3%), but decreased in the Vit. D group (-3.3% ± 3.6%). The %ΔBMD of the two groups differed significantly (p < 0.05). Although the %ΔBMD of the femoral neck showed the same tendency, the difference between two groups was not significant. Bis was significantly superior to Vit. D in maintaining the BMD of lumbar spine bones. Even in young patients with IgAN, Bis is recommended to prevent the reduction of BMD during GC treatment.