Zimmer D M, Golichowski A M, Karn C A, Brechtel G, Baron A D, Denne S C
Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis 46202-5210, USA.
Diabetes Care. 1996 Jun;19(6):591-6. doi: 10.2337/diacare.19.6.591.
Although gestational diabetes affects as many as 3% of all pregnant women, specific aspects of glucose and protein metabolism in this population have not been clearly delineated. We tested the hypothesis that gestational diabetes mellitus (GDM) results in increased glucose production and proteolysis during fasting.
Using tracer isotope infusions, the rate of appearance (Ra) of glucose, leucine, phenylalanine and tyrosine, phenylalanine hydroxylation, leucine oxidation, and urea nitrogen excretion were determined after an overnight fast in 10 GDM subjects, within 2 weeks of diagnosis and before initiation of treatment, and in a matched control group of nine healthy nondiabetic pregnant women.
Fasting glucose Ra was similar in GDM patients and control subjects (GDM, 12.8 +/- 1.1 vs. control subjects, 12.8 +/- 0.9 mumol . kg-1 . min-1). Leucine and phenylalanine Ra (reflecting proteolysis) also were not different between GDM patients and control subjects (GDM leucine Ra, 128 +/- 14 vs. control subjects, 124 +/- 5; phenylalanine Ra GDM, 35 +/- 4 vs. control subjects, 40 +/- 2 mumol . kg-1 . h-1). Furthermore, leucine oxidation and phenylalanine hydroxylation were not increased in GDM subjects, urea nitrogen excretion was actually lower in GDM patients. However, fasting insulin concentrations were significantly elevated in GDM subjects (GDM, 165 +/- 35 vs. control subjects, 30 +/- 5 pmol/l; P < 0.01).
Hepatic glucose release and whole-body proteolysis in GDM patients were remarkably similar to matched pregnant control subjects. This was achieved with insulin concentrations three- to fivefold higher than normal, suggesting significant insulin resistance for both glucose and protein metabolism in GDM.
尽管妊娠期糖尿病影响多达3%的孕妇，但该人群葡萄糖和蛋白质代谢的具体方面尚未明确界定。我们检验了以下假设：妊娠期糖尿病（GDM）会导致空腹期间葡萄糖生成增加和蛋白水解增加。
通过示踪同位素输注，在10名GDM受试者诊断后2周内且开始治疗前，以及在9名健康非糖尿病孕妇的匹配对照组中，测定过夜禁食后葡萄糖、亮氨酸、苯丙氨酸和酪氨酸的出现率（Ra）、苯丙氨酸羟化、亮氨酸氧化和尿素氮排泄。
GDM患者和对照组的空腹葡萄糖Ra相似（GDM组为12.8±1.1，对照组为12.8±0.9 μmol·kg⁻¹·min⁻¹）。GDM患者和对照组之间亮氨酸和苯丙氨酸的Ra（反映蛋白水解）也无差异（GDM组亮氨酸Ra为128±14，对照组为124±5；GDM组苯丙氨酸Ra为35±4，对照组为40±2 μmol·kg⁻¹·h⁻¹）。此外，GDM受试者的亮氨酸氧化和苯丙氨酸羟化并未增加，GDM患者的尿素氮排泄实际上更低。然而，GDM受试者的空腹胰岛素浓度显著升高（GDM组为165±35，对照组为30±5 pmol/l；P<0.01）。
GDM患者的肝脏葡萄糖释放和全身蛋白水解与匹配的孕妇对照组非常相似。这是在胰岛素浓度比正常高3至5倍的情况下实现的，表明GDM患者在葡萄糖和蛋白质代谢方面存在显著的胰岛素抵抗。
