Osei K, Schuster D P
Department of Medicine, The Ohio State University Hospitals, Columbus, USA.
Am J Med Sci. 1996 Mar;311(3):113-21. doi: 10.1097/00000441-199603000-00002.
The authors evaluated the significance of beta cell function, non-insulin-dependent glucose disposal (glucose effectiveness [Sg]), and insulin-dependent glucose disposal (insulin sensitivity) in African immigrants with varying degrees of glucose tolerance. Thirty-two African immigrants residing in Franklin County, Ohio, were studied. There were 16 subjects with normal glucose tolerance (NGT), 11 with intermediate glucose tolerance (IGT), and 5 with type II diabetes mellitus (DM). Insulin sensitivity index and Sg were measured by an insulin-modified, frequently sampled intravenous glucose tolerance test. The mean fasting and post-glucose serum glucose levels were lowest in the NGT, intermediate in the IGT group, and highest in the DM group. Mean serum insulin and c-peptide responses rose briskly by threefold to a peak in the NGT and the IGT groups. In the DM group, mean serum insulin and c-peptide responses were severely blunted to glucose stimulation. The sensitivity index was highest in the NGT (3.09 +/- 0.27), intermediate in the IGT (1.81 +/- 0.47), and lowest in the DM (0.48 +/- 0.28 x 10(-2).mins-1 (microU/ml)-1). The Sg was identical in the NGT (2.78 +/- 0.22) and IGT (2.78 +/- 0.27) groups but was slightly but not significantly lower in the DM (2.20 +/- 0.35 x 10(-2).mins-1). In addition, the glucose decay constant was not statistically different in the NGT (3.00 +/- 0.38) and IGT (2.25 +/- 0.19) group, but the mean values were significantly greater than in the patients with diabetes (0.78 +/- 0.15 percent/mins). The mean disposition index (sensitivity index X beta cell function as assessed by both insulin and c-peptide) was significantly greater in NGT than in the IGT (P<0.05) and in the diabetic group (P<0.001). In summary, the authors demonstrate that, in native African immigrants, type II diabetes is associated with significant reduction in beta cell function, insulin sensitivity, and glucose decay constant, but not in Sg. In patients with intermediate or impaired glucose tolerance, there is moderate insulin resistance and evidence of inadequate compensation by beta cell, but the Sg, the Sg at theoretical insulin concentration, and glucose decay constant remain normal. They conclude that, unlike other ethnic and racial groups, in glucose intolerant native African patients, alterations in Sg or non-insulin dependent glucose disposal (ie, tissue glucose sensitivity) do not appear to play a significant role in the impairment of glucose tolerance and type II diabetes in African immigrants.
作者评估了不同糖耐量程度的非洲移民中β细胞功能、非胰岛素依赖型葡萄糖处置（葡萄糖效能[Sg]）以及胰岛素依赖型葡萄糖处置（胰岛素敏感性）的重要性。对居住在俄亥俄州富兰克林县的32名非洲移民进行了研究。其中16名受试者糖耐量正常（NGT），11名糖耐量处于中间状态（IGT），5名患有II型糖尿病（DM）。通过胰岛素改良的频繁采样静脉葡萄糖耐量试验测量胰岛素敏感性指数和Sg。空腹和葡萄糖负荷后血清葡萄糖水平均值在NGT组最低，IGT组居中，DM组最高。NGT组和IGT组血清胰岛素和C肽平均反应迅速上升三倍至峰值。在DM组，血清胰岛素和C肽对葡萄糖刺激的平均反应严重减弱。敏感性指数在NGT组最高（3.09±0.27），IGT组居中（1.81±0.47），DM组最低（0.48±0.28×10⁻²·min⁻¹（μU/ml）⁻¹）。NGT组（2.78±0.22）和IGT组（2.78±0.27）的Sg相同，但DM组略低（2.20±0.35×10⁻²·min⁻¹），但差异无统计学意义。此外，NGT组（3.00±0.38）和IGT组（2.25±0.19）的葡萄糖衰减常数无统计学差异，但均值显著高于糖尿病患者（0.78±0.15%/min）。平均处置指数（通过胰岛素和C肽评估的敏感性指数×β细胞功能）在NGT组显著高于IGT组（P<0.05）和糖尿病组（P<0.001）。总之，作者表明，在非洲本土移民中，II型糖尿病与β细胞功能、胰岛素敏感性和葡萄糖衰减常数显著降低相关，但与Sg无关。在糖耐量处于中间状态或受损的患者中，存在中度胰岛素抵抗且有β细胞补偿不足的证据，但Sg、理论胰岛素浓度下的Sg以及葡萄糖衰减常数仍正常。他们得出结论，与其他种族群体不同，在糖耐量不耐受的非洲本土患者中，Sg或非胰岛素依赖型葡萄糖处置（即组织葡萄糖敏感性）的改变似乎在非洲移民的糖耐量受损和II型糖尿病中不起重要作用。
