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.

A novel mechanism for polychlorinated biphenyl-induced decrease in serum thyroxine level in rats.

We have previously suggested that the decrease in the levels of serum total thyroxine (T(4)) and free T(4) by a single administration to rats of Kanechlor-500 (KC500) at a dose of 100 mg/kg is not necessarily dependent on the increase in hepatic T(4)-UDP-glucuronosyltransferase (UDP-GT). In the present study, we determined whether or not a consecutive treatment with KC500 at a relatively low dose (10 mg/kg i.p., once daily for 10 days) results in a decrease in the level of serum total T(4) and further investigated an exact mechanism for the KC500-induced decrease in the T(4). At 4 days after final treatment with KC500, the serum total T(4) and free T(4) levels were markedly decreased in both Wistar and UGT1A-deficient Wistar (Gunn) rats, whereas significant increases in hepatic T(4)-UDP-GT activity were observed in Wistar rats but not in Gunn rats. The level of serum thyroid-stimulating hormone was not significantly changed in either Wistar or Gunn rats. Clearance from serum of the [(125)I]T(4) administered to the KC500-pretreated Wistar and Gunn rats was faster than that to the corresponding control (KC500-untreated) rats. The accumulated level of [(125)I]T(4) was increased in several tissues, especially the liver, in the KC500-pretreated rats. The present findings demonstrated that a consecutive treatment with KC500 resulted in a significant decrease in the level of serum total T(4) in both Wistar and Gunn rats and further indicated that the KC500-induced decrease would occur through increase in accumulation of T(4) in several tissues, especially the liver, rather than increase in hepatic T(4)-UDP-GT activity.