Short- and long-term effect of sitagliptin after near normalization of glycemic control with insulin in poorly controlled Japanese type 2 diabetic patients

Effect of sitagliptin, a DPP-4 inhibitor, against DENA-induced liver cancer in rats mediated via NF-κB activation and inflammatory cytokines

The target of the current research was to investigate the anticancer activity of sitagliptin on diethylnitrosamine (DENA)-induced cancer in the liver. Wistar rats were treated with or without sitagliptin before DENA treatment. We detected liver weight, blood glucose, and histopathology of the liver. Serum biochemical markers like serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (SALP), gamma-glutamyl transpeptidase (GGTP), total bilirubin (TBR), total protein (TPR), and albumin (ALB) were also evaluated. In addition, lipid profile parameters comprising total cholesterol (TC), triglycerides, and high-density lipoprotein were also measured. Inflammatory mediators like interleukin-6 (IL-6), interleukin-1beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) were determined in liver homogenate. Furthermore, the activity of nuclear factor (NF-κB) was also measured. Our results showed that sitagliptin (10 and 20 mg/kg) in a dose-dependent manner expressively decreased the DENA-induced elevation of SGPT, SGOT, SALP, and GGTP. Whereas sitagliptin (10 and 20 mg/kg) in a dose-dependent mode reduced the level of TBR and increased the TPR and ALB as well as improved the liver histopathology alterations in DENA-exposed rats. Lipid profile was also restored by the sitagliptin (10 and 20 mg/kg) in a DENA-treated rats. The level of IL-1β, IL-6, and TNF-α were suggestively suppressed. Moreover, pretreatment with sitagliptin (10 and 20 mg/kg) prevented the activation of NF-κB. In conclusion, sitagliptin (10 and 20 mg/kg) has a potential protective effect against DENA-induced liver cancer by inhibition of inflammation and NF-κB activation.

Short- and long-term effect of sitagliptin after near normalization of glycemic control with insulin in poorly controlled Japanese type 2 diabetic patients

AIMS/INTRODUCTION

The aim of the present study was to examine the short- and long-term effect of sitagliptin on glucose tolerance after near normalization of glycemic control with insulin in poorly controlled type 2 diabetic patients.

MATERIALS AND METHODS

We consecutively enrolled a total of 30 type 2 diabetic patients whose glycated hemoglobin levels (National Glycohemoglobin Standardization Program) were ≥7.4%, stopped all oral antidiabetic drugs and started insulin therapy. When fasting plasma glucose levels became <140 mg/dL, we carried out the first oral glucose tolerance test (OGTT). After 1-week sitagliptin treatment (50 mg/day), the second OGTT was carried out. Furthermore, we evaluated the long-term efficacy of sitagliptin on glucose tolerance after near normalization of glycemic control with insulin.

RESULTS

After 1-week sitagliptin treatment, the area under the curve of insulin was markedly increased, and the area under the curve of glucagon and glucose was markedly decreased. Duration of diabetes and insulin secretory capacity were correlated with the effect of sitagliptin. Furthermore, interestingly, near normalization of glycemic control with insulin therapy for 1-2 weeks brought out the long-term effectiveness of sitagliptin on glucose tolerance for 24 weeks, which was not observed with other antidiabetic drugs.

CONCLUSIONS

These findings suggest that near normalization of glycemic control with insulin improves the clinical response to sitagliptin in poorly controlled type 2 diabetic patients.