IMPAIRED GLUCOSE TOLERANCE AND DIABETES MELLITUS IN RENAL TRANSPLANT RECIPIETNS

Abstract

649 BACKGROUND: Post-transplant diabetes (PTDM) is a common complication in renal transplant recipients and the prevalence is 3 times greater than that of normal population in Korea. Understanding the nature of PTDM is important for an adequate management of diabetes, but the exact mechanism of PTDM is not clear, yet. METHOD: We performed an oral glucose tolerance test (OGTT) and insulin response to OGTT pre- and post-transplant, and measured basal insulin, proinsulin levels post-transplant in 57 living donor renal transplant recipients from June 1996 to January 1998. We also measured muscle and fat contents after transplantation. RESULTS: Eight patients (14%) developed PTDM, 27 patients (47%) showed impaired glucose tolerance (IGT) and 22 patients (39%) showed normal glucose tolerance (NGT) within 1 year post-transplant. There were statistically significant differences among the groups regarding pre-transplant 2-hour postload glucose levels (PTDM; 125.3±31.9 mg/dl, IGT; 108.2±20.8 mg/dl, NGT; 102.8±17.8 mg/dl), post-transplant basal insulin levels (PTDM; 3.6±1.7 μU/ml, IGT; 8.4±4.5 μU/ml, NGT; 8.2±7.6 μU/ml), proinsulin/insulin ratios (PTDM; 0.82±0.28, IGT; 0.49±0.21, NGT; 0.45±0.33) and insulin response to OGTT (30 minutes values: PTDM; 134.1±80.3 pmol/L, IGT; 193.0±110.2 pmol/L, NGT; 360.5±356.6 pmol/L) (p value < 0.05). There was a trend of increasing fat content and decreasing muscle content for PTDM patients with no statistical significance. CONCLUSION: Relatively high glucose response to pre-transplant OGTT may be used as the predictive value for the development of PTDM. The amount of insulin secretion was decreased in all three groups, but more profound in IGT and PTDM groups. Decreased insulin secretion after transplantation might be the cause of PTDM.