The effect of diabetes mellitus and Thiazolidinediones on bone histomorphometry in Streptozotocin-induced diabetic postmenopausal Wistar Rats

Osteoporosis is a metabolic skeletal disease with low bone mass and bonemicroarchitectural disorganization and it leads to inreased skeletal fragility andfracture risk. Type 1 diabetes is associated with reduction in bone mineral density.People with type 2 diabetes have often elevated bone mineral density withincreased fracture risk. Osteoporosis and diabetes both affect elderly peoples.Thiazolidinediones (TZD) increase insulin sensitivity through activation ofperoxisome proliferator-activated reseptor (PPAR) ?. TZDs are effective agents todecrease blood glucose level. One of the most important side effects of this drugsare the effect on bone,especially in postmenopausal women. Studies have shownthat PPAR? activation with TZDs increases the differentiation of precursor cellsinto adipocytes and inhibits their differentiation to osteoblasts.The purpose of this study is to evaluate the effect of diabetes and TZDs onbone. We used postmenopausal wistar rats because previus studies have shownthat the effect of TZD on bone is apparent in older rats and in estrogen-deprivedrats. Our study was the first study of postmenopausal diabetic wistar rats toevaluate the effect of TZDs on bone.İn this study we used 16 postmenopausal wistar rats. Animals weregrouped as follows (4 animals per group): 1) Control group 2) Streptozotocin68induced diabetic group without treatment (uncontrolled diabetes) 3)Streptozotocin-induced diabetic group with insulin therapy 4) Streptozotocininduceddiabetic group with rosiglitazone therapy.Compared to the control group trabecular thickness and trabecular bonearea were decreased in the uncontrolled diabetes and rosiglitazone group. İn therosiglitazone treated group trabecular thickness and trabecular bone area weredecreased compared to the uncontrolled diabetes group. Using insulin to preventhiperglisemi increases trabecular thickness and trabecular bone area. Thehistological examination of the bones showed that uncontrolled diabetes androsiglitazone treatment effects the osteoblast and osteosyte activity negatively.İnsulin treated group had a similar histologic examination to control group.