Hypomagnesemia is common early after transplantation, especially in association with calcineurin inhibitors and predicts diabetes after transplantation. Magnesium improves glycemic control and insulin sensitivity in diabetics and insulin resistant subjects without diabetes but this was never evaluated in transplant recipients.

The aim of the study is to assess whether magnesium improves glycemic control and insulin sensitivity early after transplantation.

The study is an open label study in which adult hypomagnesemic renal transplant recipients are randomized the first 2 weeks after kidney transplantation to magnesium oxide or no supplementation.

The hypothesis is that magnesium supplementation in renal transplant recipients exerts a beneficial effect on glycemia and the development of diabetes after transplantation.

Inclusion Criteria:

• Renal transplantation recipients
• > 18 years of age
• Less than 2 weeks post-transplantation
• Hypomagnesemia < 1,7 milligram/deciliter on 2 consecutive blood samples (laboratory reference interval 1,7 - 2,55 milligram/deciliter).

Exclusion Criteria:

• Pre-existing diabetes mellitus defined as the intake of anti-diabetic drugs at the time of inclusion
• Serum creatinine > 3 milligram/deciliter
• Active infection (C reactive protein > 3 milligram/deciliter)
• Severe hypomagnesemia (< 1,2 milligram/deciliter)
• Hypokalemia (< 3,5 milli-equivalent/liter)
• Severe hypocalcemia (< 6,5 milligram/deciliter)