The relationship between erythropoietin and adiponectin and the inflammatory cytokines

Inflammatory cytokines, erythropoietin (EPO) and adipocytokines, including adiponectin, leptin and tumor necrosis factor-alpha (TNF-α) play a role in pathogenesis of type 2 Diabetes mellitus. However, the relationship between erythropoietin (EPO) level and the inflammatory cytokine in type 2 diabetic patients with or without renal complication are not clear. This prospective cohort study is aimed to investigate the relationship between erythropoietin, adipocytokines and inflammatory cytokines in type 2 diabetic patients with or without renal complications based on the serum levels of their urea and creatinine. Patients were classified as group-1 (n = 66), in comparison with those suffering renal complications as group-2 (n = 54). Serum levels of EPO, adiponectin and inflammatory cytokines, TNF- α and IL-6 together with other biochemical parameters were measured in total patients suffering type 2 DM (n=120). Serum levels of EPO, adiponectin and inflammatory cytokines including; TNF- α and IL-6 were measured using enzyme linked immunosorbent assay (ELISA). Our results showed that the typ2 diabetic patients in general, had significantly high interleukin-6 concentrations (mean=25.53±2.36) and no significant difference between the two groups (p>0.05). However, TNF-α were significantly higher in group2 than group1 (p=0.01). On the other hand, serum concentration of EPO, adiponectin and haemoglobin (Hb) levels were significantly lower in group-2 than group-1 (p=0.037, p<0.005, p<0.005 respectively). There were significant positive correlations between EPO and adiponectin in the two groups (r=0.316, p<0.01 and r=0.320, p<0.05 respectively); while no significant correlation was found between EPO and TNF- α or IL-6, in either groups. In conclusion: These results show that the low serum level of EPO may associate with the low serum level of adiponectin in patients with type-2 DM, especially in those with renal complications, but not with TNF- α or IL-6.