Effects of single or combined induction of diabetes mellitus and knee osteoarthritis on some biochemical and haematological parameters in rats.

Clinical evidences on the coexistence of diabetes mellitus (DM) and osteoarthritis (OA) dated back to the 1960s. Therefore, the study investigated the effects of induced DM and/or knee osteoarthritis (KOA) on some biochemical and haematological parameters in adult male Wistar rats. Twenty rats were used for this study. They were randomly divided into 4 groups (N=5 rats) which included: Normal control; Osteoarthritic (OA) control; Diabetic control; and, Diabetic+Osteoarthritic (D+OA) control. DM was induced in overnight fasted rats by the administration of streptozotocin (65mg/kg b.w., i.p.) 15min after the administration of nicotinamide (110mg/kg, b.w., i.p.). However, KOA was induced by the intra-articular injection of 4mg of sodium monoiodoacetate in 40μl of normal saline. In the D+OA group, KOA was induced about 12h after the induction of DM. The rats were left untreated for four weeks. Afterwards, the experiment was terminated. The results showed that both DM and OA featured hypercortisolism and dyslipidaemia. The additive effects of both conditions were observed on the lipid profile and some haematological indices in the D+OA group. Unlike DM, OA had mild adverse effects on the haematological profile. Nevertheless, it significantly contributed to hyperglycaemia in the D+OA group, even though it had no significant effect on the insulin resistance. However, the hypocalcaemic and glycogenolytic effects of DM were negated by OA. In conclusion, the coexistence of DM and OA presents a greater challenge on the biochemical and haematological profiles than the individual disease. But, this prediction could sometimes be annulled by the intervention of endogenous homeostatic mechanisms.