Single-leg exercise training augments in vivo skeletal muscle oxidative flux and vascular content and function in adults with type 2 diabetes.

Autor:	Scalzo RL; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Schauer IE; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Rafferty D; Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA., Knaub LA; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Kvaratskhelia N; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA., Johnson TK; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA., Pott GB; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Abushamat LA; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Whipple MO; Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA., Huebschmann AG; Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA., Cree-Green M; Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of Pediatric Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA., Reusch JEB; Division of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Rocky Mountain Regional Veterans Administration Medical Center, Aurora, Colorado, USA., Regensteiner JG; Division of General Internal Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.; Division of Center for Women's Health Research, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA.
Jazyk:	angličtina
Zdroj:	The Journal of physiology [J Physiol] 2022 Feb; Vol. 600 (4), pp. 963-978. Date of Electronic Publication: 2021 Mar 05.
DOI:	10.1113/JP280603
Abstrakt:	Key Points: People with type 2 diabetes (T2D) have impaired skeletal muscle oxidative flux due to limited oxygen delivery. In the current study, this impairment in oxidative flux in people with T2D was abrogated with a single-leg exercise training protocol. Additionally, single-leg exercise training increased skeletal muscle CD31 content, calf blood flow and state 4 mitochondrial respiration in all participants. Abstract: Cardiorespiratory fitness is impaired in type 2 diabetes (T2D), conferring significant cardiovascular risk in this population; interventions are needed. Previously, we reported that a T2D-associated decrement in skeletal muscle oxidative flux is ameliorated with acute use of supplemental oxygen, suggesting that skeletal muscle oxygenation is rate-limiting to in vivo mitochondrial oxidative flux during exercise in T2D. We hypothesized that single-leg exercise training (SLET) would improve the T2D-specific impairment in in vivo mitochondrial oxidative flux during exercise. Adults with (n = 19) and without T2D (n = 22) with similar body mass indexes and levels of physical activity participated in two weeks of SLET. Following SLET, in vivo oxidative flux measured by 31 P-MRS increased in participants with T2D, but not people without T2D, measured by the increase in initial phosphocreatine synthesis (P = 0.0455 for the group × exercise interaction) and maximum rate of oxidative ATP synthesis (P = 0.0286 for the interaction). Additionally, oxidative phosphorylation increased in all participants with SLET (P = 0.0209). After SLET, there was no effect of supplemental oxygen on any of the in vivo oxidative flux measurements in either group (P > 0.02), consistent with resolution of the T2D-associated oxygen limitation previously observed at baseline in subjects with T2D. State 4 mitochondrial respiration also improved in muscle fibres ex vivo. Skeletal muscle vasculature content and calf blood flow increased in all participants with SLET (P < 0.0040); oxygen extraction in the calf increased only in T2D (P = 0.0461). SLET resolves the T2D-associated impairment of skeletal muscle in vivo mitochondrial oxidative flux potentially through improved effective blood flow/oxygen delivery. (© 2021 The Authors. The Journal of Physiology © 2021 The Physiological Society.)
Databáze:	MEDLINE
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