Dataset_DOM.xlsx

Aims: In this study we investigated glucose and lactate kinetics during a 75g OGTT in 23 overweight and obese adolescents and assessed putative differences among subjects with and without metabolic dysfunction-associated steatotic liver disease (MASLD). Methods: We enrolled 23 youth (6 girls) with obesity (BMI 33 [29-37]). Glucose-lactate kinetics parameters (disposal glucose insulin sensitivity, SID; fraction of glucose converted into lactate, fr; fractional lactate clearance rate, kL) and lactate production rate (LPR) were estimated by using the oral glucose-lactate minimal model (OMM). MASLD presence was assessed by using proton density fat fraction (PDFF). We analyzed glucose, lactate and LPR time to peak, peak values and area under the curve (AUC) and evaluated differences by using Wilcoxon test. MASLD and no-MASLD subjects were compared by using Mann-Whitney test. Correlations between parameters were assessed by using Spearman correlation coefficient (ρ). We also tested the performance of two (4h or 3h OGTT) protocols in estimating OMM and LPR parameters. Results: Glucose peaks 30min earlier than lactate (p=0.0019). This pattern was present in no-MASLD group (p<0.001). LPR peaks 30min later in the MASLD group (p=0.02). LPR and kL were higher in MASLD, suggesting higher glycolysis and lactate utilization. SID and fr correlate significantly (ρ= -0.55, P =0.008). SID and fr were correlated also with body mass index, BMI (ρ= -0.45, P =0.04; and ρ=0.45; P=0.03). The protocol duration did not influence parameters estimates. Discussion: MASLD subjects showed a delayed glucose metabolism possibly due to greater underlying substrates utilization. A 3-hour OGTT may be used to effectively assess lactate metabolism.