• Changes in pharmacokinetics [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  

• To determine if there is a change in side effects with the addition of sitagliptin to the post-kidney transplant treatment regime. [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  
• To determine the effect of sitagliptin on glucose lowering over 3 months as measured by the change in HgbA1c. [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  
• To determine if the addition of sitagliptin changes tacrolimus or sirolimus drug levels in post-kidney transplant patients [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  
• Determine tolerability of sitagliptin therapy in post-kidney transplant patients. [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  

Within the last six months, the FDA has approved sitagliptin phosphate as an oral drug that potentiates the effect of native GLP-1 through inhibition of DPP-4. It is approved for treatment of type 2 diabetes in adults as monotherapy or in combination with metformin or a TZD. It has several advantages over extenatide when considering its use in kidney transplant recipients:

1. It is administered orally once a day
2. Nausea occurred at a rate of only 1.4%
3. Its potential of hypoglycemia is low

However, it may not be as potent, in terms of HbA1C with % change in HbA1C<1%. In addition there is not a lot of information on gastric emptying, although this is probably not as severe as exenatide, with fewer symptoms of nausea reported.

We propose to conduct a pilot study for using sitagliptin in patients who have both type 2 diabetes and who have received a kidney transplant. Our objectives are to study the effect of sitagliptin administration on side effect profiles, change in HbA1C, and the percentage of patients who require discontinuation of the drug as a result of major changes in immunosuppressant drug levels. The data will be used as preliminary data for a larger study that attempts to prevent or delay the onset of PTDM in kidney transplant recipients. We anticipate treating patients with both impaired fasting glucose and normoglycemia, given the high frequency of PTDM in the post-kidney transplant population.