Department of Nephrology and Transplantation, Renal Institute of Birmingham, University Hospital Birmingham, Edgbaston, Birmingham, United Kingdom.
Transplantation. 2010 Jun 15;89(11):1341-6. doi: 10.1097/TP.0b013e3181d9e1d8.
beta-Cell dysfunction and insulin resistance combine to cause new-onset diabetes after transplantation. The product of these two parameters, quantitatively measured as disposition index (DI), is a mathematical constant in normoglycemia and declines in advance of impending hyperglycemia. The aim of this study was to derive a simple surrogate for the DI to expose predysglycemic abnormalities posttransplantation.
First-phase insulin secretion and sensitivity were determined by mathematical minimal model analysis of 58 frequently sampled, intravenous glucose tolerance tests in 58 non-diabetic renal transplant recipients and correlated against surrogate indexes based on fasting blood samples. Products of insulin secretion/resistance indexes were correlated against calculated DI, regression analysis performed for hyperbolic compatibility, autocorrelation studies conducted, and surrogates tested in various subgroups of renal transplant recipients to ensure robustness in a heterogeneous group.
The best correlation was achieved with "HOMA(sec) (first-phase insulin secretion)xMcAuley's index (insulin resistance)" (r=0.594, P<0.001). Regression analysis was consistent with a mathematical hyperbola (ln HOMA(sec) vs. ln McAuley's index, r=-0.639 [95% confidence interval, -1.772 to -0.950]), statistical autocorrelation was excluded (in a subset of 20 patients with repeat metabolic investigations), and the surrogate remained valid in different subgroups of transplant recipients.
Our surrogate "HOMA(sec)xMcAuley's index," requiring only fasting glucose, insulin, and triglycerides, is a simple and noninvasive surrogate for the DI. Its predictive utility for identifying impending hyperglycemia posttransplantation should be investigated further to ascertain whether its experimental nature can translate to clinical validity.
β细胞功能障碍和胰岛素抵抗共同导致移植后新发糖尿病。这两个参数的乘积，即定量测量的处置指数（DI），在正常血糖下是一个数学常数，并且在即将发生高血糖之前会下降。本研究的目的是得出 DI 的简单替代物，以揭示移植后 predysglycemic 异常。
对 58 例非糖尿病性肾移植受者的 58 次频繁采样静脉葡萄糖耐量试验进行数学最小模型分析，以确定第一相胰岛素分泌和敏感性，并与基于空腹血样的替代指标相关。胰岛素分泌/抵抗指数的乘积与计算出的 DI 相关，进行双曲线兼容性回归分析，进行自相关研究，并在各种肾移植受者亚组中测试替代物，以确保在异质组中稳健性。
与“HOMA(sec)（第一相胰岛素分泌）xMcAuley's 指数（胰岛素抵抗）”（r=0.594，P<0.001）相关性最佳。回归分析与数学双曲线一致（ln HOMA(sec) 与 ln McAuley's 指数，r=-0.639[95%置信区间，-1.772 至-0.950]），排除了统计自相关（在 20 例重复代谢研究的亚组中），替代物在不同的移植受者亚组中仍然有效。
我们的替代物“HOMA(sec)xMcAuley's 指数”，仅需要空腹血糖、胰岛素和甘油三酯，是 DI 的简单、非侵入性替代物。其在识别移植后即将发生高血糖方面的预测效用应进一步研究，以确定其实验性质是否能转化为临床有效性。
