Assessment of postprandial hepatic glycogen synthesis from uridine diphosphoglucose kinetics in obese and lean non-diabetic subjects

BACKGROUND: Obese patients are frequently characterized by insulin resistan ce and decreased insulin-mediated glycogen synthesis in skeletal muscle. Wh ether they also have impaired postprandial hepatic glycogen synthesis remai ns unknown. AIM: To determine whether postprandial hepatic glycogen synthesis is decrea sed in obese patients compared to lean subjects. METHODS: Lean and obese subjects with impaired glucose tolerance were studi ed over 4 h after ingestion of a glucose load. Hepatic uridine diphosphoglu cose kinetics were assessed using C-13-galactose infusion. with monitoring of urinary acetaminophen - glucuronide isotopic enrichment to estimate hepa tic glycogen kinetics. RESULTS: Estimated net hepatic glycogen synthesis amounted to 18.6 and 22.6 % of the ingested load in lean and obese subjects, respectively. CONCLUSION: Postprandial hepatic glycogen metabolism is not impaired in non -diabetic obese subjects.