RESUMO
Objective To investigate changes of serum silent information regulator 1 (Sirt1) and inflammatory cytokines in type 2 diabetes patients with different stages of diabetic nephropathy.To explore the relationship between serum Sirt1 level and inflammatory cytokines in type 2 diabetic patients with different urinary albumin excretion rates.Methods A total of 436 cases with type 2 diabetes were divided into three groups:normoalbuminuric [D1,n =168],microalbuminuric [D2;n =152],and macroalbuminuric [D3,n =116].Serum Sirt1,hypoxia-inducible factor-1α (HIF-1α),early growth response protein 1 (EGR1),insulin-like growth factors-Ⅰ (IGF-Ⅰ),and monocyte chemotactic protein-1 (MCP-1) were determined by enzyme-linked immunosorbent assay (ELISA).Results The levels of serum Sirt1 in type 2 diabetes patients were significantly lower than that in control group,and with the increase of urinary protein excretion rate,the levels of serum Sirt1 in group D1,D2 and D3 were decreased gradually (P ＜ 0.01).Compared to control,serum inflammatory cytokines (HIF-1α,EGR1,IGF-Ⅰ,and MCP-1) levels were significantly increased in type 2 diabetic patients and gradually increased in the patients of D1,D2 and D3 groups (P ＜0.01).Furthermore,Serum Sirt1 was negatively correlated with the levels of inflammatory cytokines.Age,duration,fasting blood glucose (FBG),fasting insulin (FINS),homeostasis model assessment insulin resistance index (HOMA-IR),glycosylated hemoglobin (HbA1c),low density lipoprotein (LDL),total cholesterol (TC),triglyceride (TG),serum creatinine (Scr),blood urea nitrogen (BUN),uric acid (UA),HIF-1α,EGR1,IGF-Ⅰ,and MCP-1 were positively correlated with Ln Koc of urinary albumin to creatinine ratio [Ln(ACR)] (P ＜ 0.05);and Sirt1 were negatively correlated with Ln(ACR)(P ＜ 0.01).HIF-1α,MCP-1,IGF-Ⅰ,duration,BUN,Sirt1,UA,LDL,and EGR1 were independent factors that significantly influenced Ln (ACR) (P ＜ 0.05).Conclusions Serum Sirt1 might be a new target for the treatment of diabetic nephropathy.Enhancing serum Sirt1 levels might have a role in delaying the progression of diabetic nephropathy.