Purpose: The purpose of this study was to characterize the effect of acute resistance exercise on post-prandial lipid metabolism in obese men with prediabetes using a novel dual-tracer approach.
Participants: Ten men with obesity (age 47 ± 10, BMI 33 ± 2) and prediabetes (fasting glucose 110 ± 4 mg/dL, HbA1c 5.6% ± .2%, 2-hour OGTT glucose 162 ± 14 mg/dL).
Methods: Randomized cross-over design. Participants completed a 1-hour bout of whole-body resistance exercise (RE: 8 exercises, 3 sets, 12 reps, 80% 1RM), or 1-hour of rest on separate visits. Participants received a constant infusion of [U-13C16] palmitate and consumed a mixed meal containing 10 mg/kg body weight of [(13C4-palmitate)3] tripalmitin to assess incorporation of endogenous and exogenous fatty acids into postprandial lipids, respectively. Plasma samples were analyzed for total triglyceride (TG), chylomicron, triglyceride rich lipoprotein (TRL), and fatty acid concentrations and isotopic enrichment of tracers. Indirect calorimtery was used to measure whole-body lipid oxidation. Skeletal muscle biopsies were used to measure muscle mitochondrial fatty acid oxidation capacity using high-resolution respirometry.
Results: Compared to rest, a single bout of RE reduced post-prandial total TG, chylomicron-TG, VLDL-TG, and TRL-TG concentration area under the curve (all p<0.05). Enrichment analyses revealed the contribution of meal-derived TG to circulating chylomicrons and TRL was significantly reduced after RE, as was the contribution of TG in chylomicrons that came from the meal (all p<0.05). RE increased whole-body lipid oxidation for up to three hours after the exercise session, and significantly improved skeletal muscle oxidative capacity (p=.031).
Conclusions: Resistance exercise improves post-prandial lipid clearance and oxidation, thereby reducing post-prandial triglyceride excursions in men with obesity and prediabetes. These improvements could lower the risk of CVD and progression to T2DM.
A. Bittel: None. D. Bittel: None. B.W. Patterson: None. B. Mittendorfer: None. W.T. Cade: None.