Balasubramanyam A, McKay S, Nadkarni P, Rajan A S, Garza A, Pavlik V, Herd J A, Jahoor F, Reeds P J
Division of Endocrinology, Baylor College of Medicine, Houston, Texas, USA.
Am J Physiol. 1999 Nov;277(5):E905-14. doi: 10.1152/ajpendo.1999.277.5.E905.
We investigated the effect of nutrient intake on glucose metabolism in normal Mexican-Americans (n = 6) and European-Americans (n = 6). Subjects were studied after an 18-h fast and after 5-6 h of ingestion of hourly meals that supplied 6.35 or 12.75 micromol glucose. kg(-1). min(-1). Endogenous glucose production (EGP), gluconeogenesis (GNG), and glycogenolysis (GLY) were estimated by mass isotopomer analysis with [U-(13)C]glucose infusions. Fasting EGP, GNG, and GLY did not differ between the groups. Food ingestion lowered the molar rate of GNG by only 31%. However, while consuming the lower quantity of nutrients, Mexican-Americans had higher plasma glucose (P < 0.05), a 39% higher rate of EGP (P < 0.05), and a 68% (P < 0.025) higher rate of GLY than the European-Americans. At the higher intake, EGP and GLY were suppressed completely in both groups. There was a linear relationship between insulin concentrations, EGP, and GLY in both groups, but the slope of the line was significantly (P < 0.05) greater in the European-Americans. We conclude that the sensitivity of GLY to nutrient intake differs between ethnic groups and that this may play a role in the increased predisposition of Mexican-Americans to type II diabetes.
我们研究了营养摄入对正常墨西哥裔美国人（n = 6）和欧裔美国人（n = 6）葡萄糖代谢的影响。受试者在禁食18小时后以及摄入每小时提供6.35或12.75微摩尔葡萄糖·千克⁻¹·分钟⁻¹的餐食5 - 6小时后接受研究。通过[U-(¹³)C]葡萄糖输注的质量同位素异构体分析来估计内源性葡萄糖生成（EGP）、糖异生（GNG）和糖原分解（GLY）。两组之间的空腹EGP、GNG和GLY没有差异。食物摄入仅使GNG的摩尔速率降低了31%。然而，在摄入较低量营养素时，墨西哥裔美国人的血糖水平较高（P < 0.05），EGP速率比欧裔美国人高39%（P < 0.05），GLY速率比欧裔美国人高68%（P < 0.025）。在较高摄入量时，两组的EGP和GLY均被完全抑制。两组中胰岛素浓度、EGP和GLY之间均存在线性关系，但欧裔美国人的直线斜率显著更大（P < 0.05）。我们得出结论，不同种族之间GLY对营养摄入的敏感性存在差异，这可能在墨西哥裔美国人患II型糖尿病的易感性增加中起作用。
