Effect of Bisphosphonate in Insufficiency state of vitamin D. Preliminary Experimental Study.

ZENI SN, MASTAGLIA SR, MANDALUNIS P, DEGRANDI MC, OLIVERI MB, SOMOZA J

Seattle, Washington , USA

Congreso; Twenty- Sixth Annual Meeting of the American Society for Bone and Mineral Research; 2004

The American Society for Bone and Mineral Research

Effect Of Bisphosphonate In Insufficiency State Of Vitamin D. Preliminary Experimental Study S. N. Zeni1, S. R. Mastaglia*1, P. Mandalunis*2, M. C. Degrandi*1, M. B. Oliveri1, J. Somoza*1. 1Sección Osteopatías Médicas, Hospital de Clínicas, University of Buenos Aires, Buenos Aires, Argentina, 2Catedra de Fisiología, School of Dentistry, University of Buenos Aires, Buenos Aires, Argentina. It is known that vitamin D insufficiency or deficiency has negative effects on skeletal metabolism. Experimental bone loss is achieved by ovariectomy (OVX) in rats by incresing bone turnover. Bisphosphonates (BPs) are useful antiresortive agents to inhibit resorption in several bone diseases. Hypothetically vitamin D insufficiency could affect bisphosphonate therapy. The aim of the present preliminary study was to investigate whether bone mass recovery due to olpadronate (OPD) treatment is affected by Vitamin D status- i.e. normal or insufficiency, using OVX rats with established osteopenia. A total of 16 female Wistar rats (280-300 g) were OVX: 8 rats were fed a synthetic diet that covered all adequate requirements (+VitD); 8 rats were housed under red light and fed the same synthetic diet lacking of Vitamin D (-VitD). During 60 days rats lost approximately 15% of bone mass, after that (To) 8 rats of +VitD group and all rats of -VitD group received during a 45-day period (Tf) 16ug OPD/100g rat weekly. Simultaneously, 8 OVX and 8 SHAM rats were fed the synthetic diet throughout the study and only received placebo treatment. Bone mineral density (BMD) (mg/cm2), 25OHvitamin D (ng/ml), bone alkaline phosphate (mUI/ml) and serum CTX (ng/ml) were assessed at To and Tf and tibia histomorphometry was made at Tf. (Table).Different letters indicated a p<0.05. Bone recovery by OPD treatment was greater in +VitD than in -Vit D. At Tf sCTX was lower and 25OHVitD was higher than in -VitD group. The +VitD group presented greater bone volume and lower erosive surface than -VitD group. Conclusion: These results suggest that OPD effects may be less beneficial in vitamin D deficient state. Delta: Changes (Tf-To) in total skeleton (TE) and lumbar spine (LS). OPD+VitD OPD-VitD SHAM+VitD OVX+VitD DeltaBMD(TE) 12±4 a 5±3 a 10±3 a -1±2 b DeltaBMD(LS) 3.3±3.0 a 1.8±2.0 b 2.5±1.9 a -5.3±2.4 b Tf sCTX 99±10 a 138±11 b 181±13 c 204±13 d Tf 25OHD 59.0±3.5 a 9.2±0.8 b 62.1±2.9 a 46.5±3.9 a BV/BS% 29.9±5.6 a 19.7±8.1 b 28.2±8.4 a 12.6±5.1 b ES/BS% 19.8±2.2 a 26.5±1.9 b 17.5±3.4 a 28.5±3.2 b