The objective of the present study is to evaluate both the efficacy and safet of nateglinide in renal transplanta recipients with posttransplant diabetes mellitus or impaired glucose tolerance. Primarily will the change in glucose tolerance and acute insuline responce be addressed.

Inclusion Criteria:

• Reduced glucose tolerance (fasting glucose < 6.1 mmol/L AND 2 hour glucose between 6.7 and 9.9 mmol/L) or posttransplant diabetes mellitus (fasting glucose > 6.1 mmol/L OR 2 hour glucose between >= 10.0 mmol/L)
• Stable patients fgollowing renal transplantation, less than 25% variation in serum creatinine last week and serum creatinine < 200 micromol/L

Exclusion Criteria:

• Patients with indulin dependent diabetes mellitus before or after transplantation
• Planned change in daily prednisolone dose during the study period
• Haemoglobin < 8g/dL