Epidemiology of microvascular complications of diabetes in South Asians and comparison with other ethnicities

Type 2 diabetes mellitus is widely prevalent in South Asians, and has a significant effect on health, as well as the economies of South Asian countries, particularly when the disease is associated with complications. There are certain characteristics associated with the South Asian phenotype that make South Asians especially prone to diabetes, as well as its complications. Microvascular complications cause considerable morbidity and mortality. There are significant differences in the epidemiology of microvascular complications between South Asians and people of other races. There is evidence of higher prevalence of nephropathy and retinopathy in South Asians compared with Caucasians; however, recent studies indicate that this trend seems to be leveling off. Importantly, diabetic neuropathy occurs less frequently in South Asians compared with Caucasians. These observations have important implications in managing South Asian patients with diabetes and microvascular complications.

Renoprotective effect of atorvastatin on STZ-diabetic rats through attenuating kidney-associated dysmetabolism

Atorvastatin (AT) has been alternatively used for managing diabetic complications in clinic. However, AT-related therapeutic potentiality remains relatively unexplored, especially in diabetic nephropathy. This study aimed to investigate the underlying potentiality that AT exerted on anti-diabetic nephropathy role against streptozotocin (STZ)-induced kidney injury in rats. STZ-diabetic rats were intragastrically administered with AT (10, 20 mg/kg/d) for consecutive 8 weeks. The effects of AT on body weight, levels of blood glucose, lipometabolism, redox state, cellular metabolism, regulator factor and kidney morphological changes were monitored by routine measurement, biochemistry assay, PT-PCR analysis, ultrastructural and pathological observations, respectively. Compared with the diabetic nephropathy rats, AT elevated the body weight of diabetic nephropathy rats (P<0.01), effectively reduced the blood glucose level (P<0.01), increased the levels of insulin and high-density lipoprotein cholesterol (HDL-C) in plasma (P<0.01), and decreased the 24 h urine protein content and serum concentrations of low-density lipoprotein cholesterol (LDL-C) (P<0.01). Meanwhile, increase in kidney tissue, the intrarenal activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were enhanced, while the malonaldehyde (MDA) content was reduced (P<0.01). In addition, the expression of transforming growth factor beta 1 (TGF-β1) mRNA in kidney tissue was notably down-regulated (P<0.01). Furthermore, AT contributed to alleviating STZ-induced nephritic damages in rats. These results demonstrate that atorvastatin exerts the effective protective role against kidney injuries of STZ-induced diabetic nephropathy rat, which the underlying mechanisms are associated with ameliorating glyco, lipometabolism, enhancing antioxidant ability, and mitigating renal damage.

Transforming growth factor beta 1 and monocyte chemoattractant protein-1 as prognostic markers of diabetic nephropathy

We aimed to find the relationship between serum transforming growth factor beta 1(TGF-β1) and urinary monocyte chemoattractant protein-1 (MCP-1) throughout the course of diabetic nephropathy (DN) and to assess the relationship between both levels and other parameters of renal injury such as albumin/creatinine ratio and estimated glomerular filtration rate (eGFR). Serum TGF-β1, urinary MCP-1, eGFR, and glycosylated hemoglobin (HbA1c) were measured in 60 patients with type II diabetes mellitus with different degrees of nephropathy (20 patients with normoalbuminuria, 20 patients with microalbuminuria, and 20 patients with macroalbuminuria) and compared with 20 matched healthy control subjects. Both the levels of serum TGF-β1 and urinary MCP-1 were significantly higher in patients with micro- and macroalbuminuria (137.8 ± 69.5 and 329.25 ± 41.46 ng/dl, respectively, for TGF-β1 and 167.41 ± 50.23 and 630.87 ± 318.10 ng/g creatinine, respectively, for MCP-1) compared with normoalbuminuric patients and healthy controls (33.25 ± 17.5 and 29.64 ± 10.57 ng/dl, respectively, for TGF-β1 and 63.85 ± 21.15 and 61.50 ± 24.81 ng/g creatinine, respectively, for MCP-1; p < 0.001). There was a positive significant correlation between the levels of serum TGF-β1 and those of urinary MCP-1 ( r = 0.73, p < 0.001). Also, serum TGF-β1 and urinary MCP-1 correlated positively with HbA1c ( r = 0.49 and 0.55, respectively, p < 0.05 for both) and inversely with eGFR ( r = −0.69 and −0.60, respectively, p < 0.001 for both). We can conclude that serum TGF-β1 and urinary MCP-1 can be used as the markers for detection of progression of DN. Antagonizing TGF-β1 and MCP-1 might be helpful in attenuating the progression of nephropathy in diabetic patients.

Zhenqing recipe alleviates diabetic nephropathy in experimental type 2 diabetic rats through suppression of SREBP-1c

ETHNOPHARMACOLOGICAL RELEVANCE

Zhenqing Recipe (ZQR), a Chinese herbal prescription, is used to improve renal function of patients with diabetic nephropathy. In current research, the therapeutic effects of ZQR on type 2 diabetic nephropathy and the underlying molecular mechanisms were explored.

MATERIALS AND METHODS

Animal model with diabetic nephropathy was developed by high fat/sucrose diet feeding plus streptozotocin injection for 4 weeks. The diabetic rats were then orally administered with ZQR extract at the dose of 4 g/kg, 8 g/kg body weight/day for 8 weeks.

RESULTS

Serum glucose, triglyceride and total cholesterol in untreated diabetic rats were significantly higher than that of normal control rats. ZQR treatment not only reduced serum glucose level in diabetic rats, but also decreased serum triglyceride and total cholesterol in a dose-dependent manner. Urinary albumin excretion rate, serum urea and creatinine were significantly decreased in ZQR groups compared with untreated diabetic group. Histopathological study of kidney samples showed that extracellular mesangial matrix expansion in diabetic rats was suppressed by ZQR treatment. Both mRNA and protein levels of sterol regulatory element binding-protein-1c (SREBP-1c), and its target genes including acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) in renal cortex were significantly decreased in ZQR treated rats compared to untreated diabetic rats. Consequently, renal triglyceride was significantly reduced in ZQR groups. Furthermore, ZQR significantly inhibited the overexpression of transforming growth factor-β1 and fibronectin in the renal cortex of diabetic rats.

CONCLUSIONS

Oral treatment of ZQR improved diabetic nephropathy by inhibiting the overexpression of SREBP-1c and its target genes including ACC and FAS in experimental type 2 diabetic rats.