A dual sugar challenge test for lipogenic sensitivity to dietary fructose.

ABSTRACT: Increased hepatic de novo lipogenesis (DNL) in response to dietary sugar is implicated in dyslipidemia, fatty liver, and insulin resistance.The aim of the study was to develop a simple outpatient tolerance test for lipogenic sensitivity to dietary sugar.In inpatients given repeated doses of fructose, protocol 1 compared the acute increase in DNL determined from the percentage of palmitate ("new palmitate") and the percentage of isotopically labeled palmitate ("%DNL") in very low-density lipoprotein triglyceride (TG). Protocol 2 compared the increase in new palmitate in outpatients given three different sugar beverages in a randomized crossover design.There were 15 lean and overweight volunteers in protocol 1 and 15 overweight volunteers in protocol 2.In protocol 1, subjects received 1.4 g/kg fructose in divided oral doses over 6 h; in protocol 2, subjects received 0.5 g/kg fructose, 0.5 g/kg fructose plus 0.5 g/kg glucose, or 1 g/kg fructose plus 1 g/kg glucose each as a single oral bolus.We measured the increase in DNL by two methods.After repeated doses of fructose, new palmitate was significantly correlated with the increase in %DNL (?, r = 0.814; P < 0.001) and with fasting insulin levels (area under the curve, r = 0.754; P = 0.001). After a single sugar dose, new palmitate showed a dose effect and was greater after fructose plus glucose. Very low-density lipoprotein TG and total TG significantly increased in both protocols.A single oral bolus of fructose and glucose rapidly increases serum TG and TG palmitate in overweight subjects. A dual sugar challenge test could prove useful to identify individuals at risk for carbohydrate-induced dyslipidemia and other adverse effects of increased DNL.

SUBMITTER: Hudgins LC 

PROVIDER: S-EPMC3047222 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature