Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common human enzymopathy that affects cellular redox status and may lower flux into nonoxidative pathways of glucose metabolism. Oxidative stress may worsen systemic glucose tolerance and cardiometabolic syndrome. We hypothesized that G6PD deficiency exacerbates diet-induced systemic metabolic dysfunction by increasing oxidative stress bu...

Fery, F., L. Plat, and E. O. Balasse. Effect of fasting on the intracellular metabolic partition of intravenously infused glucose in humans. Am. J. Physiol. 277 (Endocrinol. Metab. 40): E815–E823, 1999.—The effects of fasting on the pathways of insulin-stimulated glucose disposal were explored in three groups of seven normal subjects. Group 1 was submitted to a euglycemic hyperinsulinemic clamp...

High plasma insulin has been shown to be associated with the risk of coronary heart disease in nondiabetic subjects in prospective population studies. Furthermore, insulin resistance measured by the euglycemic glucose clamp technique has been shown to be related to lipid and lipoprotein changes favoring atherosclerosis and to high blood pressure. No study, however, has demonstrated that insulin...

Controversy exists regarding the relative importance of adiposity, physical fitness, and physical activity in the regulation of insulin-stimulated glucose disposal. To address this issue, we measured insulin-stimulated glucose disposal [mg. kg fat-free mass (FFM)(-1). min(-1); oxidative and nonoxidative components] in 45 nondiabetic, nonobese, premenopausal women (mean +/- SD; 47 +/- 3 yr) by u...

The etiology of type 2 diabetes is multifactorial, including genetic as well as pre- and postnatal factors that influence several different defects of glucose homeostasis, primarily in muscle, beta-cells, and liver. In the present twin study, we report heritability estimates (h(2)) for measures of insulin secretion, insulin resistance, hepatic glucose production (HGP), and intracellular glucose...

Although chronic hyperinsulinemia has been shown to induce insulin resistance, the basic cellular mechanisms responsible for this phenomenon are unknown. The present study was performed 1) to determine the time-related effect of physiological hyperinsulinemia on glycogen synthase (GS) activity, hexokinase II (HKII) activity and mRNA content, and GLUT-4 protein in muscle from healthy subjects, a...

Recent studies have demonstrated that reduced insulin-stimulated muscle glycogen synthesis is the major cause of insulin resistance in patients with non-insulin-dependent diabetes mellitus (NIDDM). This reduced rate has been assigned to a defect in either glucose transport or hexokinase activity. However it is unknown whether this is a primary or acquired defect in the pathogenesis of NIDDM. To...