pubmed-article:7815676 | pubmed:abstractText | To investigate whether increased availability of lipids affects glucose metabolism in healthy postabsorptive men when lipid and glucose are infused in amounts used in parenteral nutrition, we infused glucose (4 mg/kg.min-1) for 6 hours and clamped plasma glucose at basal level during the first 3 hours. After 3 hours, either long-chain triglycerides (LCTs) (0.07 g/kg.h-1) (n = 7) or a mixture of LCTs and medium-chain triglycerides (MCTs) (MCTs/LCTs, 50/50%, 0.07 g/kg.h-1) (n = 7) was administered, and the infusion rates of glucose and insulin were unchanged compared with the first 3 hours. In a control study, glucose was infused for a period of 6 hours without the lipid infusion (n = 5). After 6 hours, the plasma glucose concentration and glucose tissue uptake were not affected by LCT or MCT/LCT infusion. Nonetheless, glucose oxidation decreased in the LCT group (from 6.42 +/- 1.04 to 2.31 +/- 0.85 mumol/kg.min-1, p < .001) and in the MCT/LCT group (from 7.62 +/- 1.50 to 5.50 +/- 0.76 mumol/kg.min-1, p < .01) but not in the control group. Concentrations of the glucoregulatory hormones were not different among the three groups. In conclusion, MCTs/LCTs administered concomitantly with glucose infusion, in amounts similar to those used in total parenteral nutrition, inhibit glucose oxidation without affecting glucose tissue uptake, just as LCTs do. | lld:pubmed |