High-fat/low-carbohydrate diets regulate glucose metabolism via a long-term transcriptional loop.

Insulin sensitivity is characterized by insulin-stimulated glucose metabolism in skeletal muscle. We hypothesized that carbohydrate metabolism and storage might be under transcriptional control. To test this hypothesis, we fed insulin-sensitive males (glucose disposal rate, 14.7 +/- 4.1 mg/kg fat-free mass [FFM] per minute) an isoenergetic high-fat/low-carbohydrate diet (HF/LCD) for 3 days with muscle biopsies before and after intervention. Oligonucleotide microarrays revealed a total of 369 genes of 18861 genes on the arrays were differentially regulated in response to diet (Bonferonni adjusted P < .01). A similar experiment was conducted in mice with a 3-week intervention using a control group and an HF/LCD group to offset the lack of a control group within the human cohort. As part of an analysis of results previously published from this data set, 7 genes in the carbohydrate metabolism pathway changed in response to the HF/LCD, and 3 genes were confirmed by quantitative reverse transcriptase-polymerase chain reaction: fructose-2,6-biphosphatase 3 (PFKFB3), pyruvate dehydrogenase kinase, isoenzyme 4 (PDK4), and glycogen synthase 1 (muscle). In a separate experiment, we fed C57Bl/6J mice an HF/LCD for 3 weeks and found that the same glucose metabolism genes were changed by approximately 70% on average. Fructose-2,6-biphosphatase 3 and pyruvate dehydrogenase kinase, isoenzyme 4 increased and glycogen synthase 1 (muscle) decreased. Combined, these results suggest a mechanism whereby HF/LCD regulates the genes necessary for glucose utilization and storage vis-á-vis transcriptional control.