Influences of Hypoxia Exercise on Whole-Body Insulin Sensitivity and Oxidative Metabolism in Older Individuals

authored by

Kristine Chobanyan-Jürgens, Renate J. Scheibe, Arne B. Potthast, Markus Hein, Andrea Smith, Robert Freund, Uwe Tegtbur, Anibh M. Das, Stefan Engeli, Jens Jordan, Sven Haufe

Abstract

Context: Aging is a primary risk factor for most chronic diseases, including type 2 diabetes. Both exercise and hypoxia regulate pathways that ameliorate age-associated metabolic muscle dysfunction. Objective: We hypothesized that the combination of hypoxia and exercise would be more effective in improving glucose metabolism than normoxia exercise. Design and Participants: We randomized 29 older sedentary individuals (62 ± 6 years; 14 women, 15 men) to bicycle exercise under normobaric hypoxia (fraction of inspired oxygen = 15%) or normoxia (fraction of inspired oxygen = 21%). Intervention: Participants trained thrice weekly for 30 to 40 minutes over 8 weeks at a heart rate corresponding to 60% to 70% of peak oxygen update. Main Outcome Measures: Insulin sensitivity measured by hyperinsulinemic-euglycemic glucose clamp and muscle protein expression before and after hyperinsulinemic-euglycemic glucose clamp. Results: Heart rate and perceived exertion during training were similar between groups, with lower oxygen saturation when exercising under hypoxia (88.7 ± 1.5 vs 96.2 ± 1.2%, P < 0.01). Glucose infusion rate after 8 weeks increased in both the hypoxia (5.7 ± 1.1 to 6.7 ± 1.3 mg/min/kg; P < 0.01) and the normoxia group (6.2 ± 2.1 to 6.8 ± 2.1 mg/min/kg; P = 0.04), with a mean difference between groups of -0.44 mg/min/kg; 95% CI, -1.22 to 0.34; (P = 0.25). Markers of mitochondrial content and oxidative capacity in skeletal muscle were similar after training in both groups. Changes in Akt phosphorylation and glucose transporter 4 under fasting and insulin-stimulated conditions were not different between groups over time. Conclusions: Eight weeks of hypoxia endurance training led to similar changes in insulin sensitivity and markers of oxidative metabolism compared with normoxia training. Normobaric hypoxia exercise did not enhance metabolic effects in sedentary older women and men beyond exercise alone.

External Organisation(s)

Hannover Medical School (MHH)
Heidelberg University
German Aerospace Center (DLR)

Type

Article

Journal

Journal of Clinical Endocrinology and Metabolism

Volume

104

Pages

5238-5248

No. of pages

11

ISSN

0021-972X

Publication date

11.2019

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Endocrinology, Diabetes and Metabolism, Biochemistry, Endocrinology, Clinical Biochemistry, Biochemistry, medical

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1210/jc.2019-00411 (Access: Closed)