Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2014 Feb;22(2):451-7.
doi: 10.1002/oby.20609. Epub 2013 Oct 16.

Metabolic inflexibility during submaximal aerobic exercise is associated with glucose intolerance in obese older adults

Steven J Prior  1 , Alice S Ryan, Troy G Stevenson, Andrew P Goldberg
Affiliations
Comparative Study

Metabolic inflexibility during submaximal aerobic exercise is associated with glucose intolerance in obese older adults

Steven J Prior et al. Obesity (Silver Spring). 2014 Feb.

Abstract

Objective: People with type 2 diabetes have reduced cardiorespiratory fitness and metabolic impairments that are linked to obesity and often occur prior to the development of type 2 diabetes. We hypothesized that obese, older adults with impaired glucose tolerance (IGT) have lower ability to shift from fat to carbohydrate oxidation when transitioning from rest to submaximal exercise than normal glucose tolerant (NGT) controls.

Design and methods: Glucose tolerance, body composition, and substrate oxidation (measured by RER:respiratory exchange ratio) during submaximal exercise (50% and 60% VO₂max ) and insulin infusion (3-hour hyperinsulinemic-euglycemic clamp) were assessed in 23 sedentary, overweight-obese, older men and women.

Results: Obese subjects with NGT (n = 13) and IGT (n = 10) had similar resting RER, but during submaximal exercise those with IGT had a lower RER and less transition to carbohydrate oxidation than the NGT group (P < 0.05). The IGT group also oxidized less carbohydrate during insulin infusion than NGT (P < 0.05). RER at each exercise intensity independently correlated with 120-minute postprandial glucose (r = -0.54 to -0.58, P < 0.05), but not with body composition, VO₂max , or RER during insulin infusion.

Conclusions: Obese, older adults have metabolic inflexibility during exercise that is associated with the degree of glucose intolerance independent of age and body composition.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Attenuated increase in respiratory exchange ratio (A), and higher kilocalories derived from fat (B) during submaximal exercise in older adults with impaired glucose tolerance (IGT) compared to controls with normal glucose tolerance (NGT). Data are means ± SEM. *,†Significant difference in RER, fat oxidation rate, or kcal derived from fat between NGT and IGT groups, *p < 0.05, †p = 0.01. RER: respiratory exchange ratio, CHO: carbohydrate, LBM: lean body mass.
Figure 2
Figure 2
Glucose intolerance (120-minute postprandial plasma glucose) is associated with lower respiratory exchange ratio (RER) (i.e., lower carbohydrate oxidation) during aerobic exercise at (A) 50% and (B) 60% VO2max.
See this image and copyright information in PMC

References

    1. Cowie CC, Rust KF, Ford ES, et al. Full accounting of diabetes and pre-diabetes in the U.S. population in 1988–1994 and 2005–2006. Diabetes Care. 2009;32(2):287–94. - PMC - PubMed
    1. Kelley DE, Mandarino LJ. Fuel selection in human skeletal muscle in insulin resistance: a reexamination. Diabetes. 2000;49(5):677–83. - PubMed
    1. Faerch K, Vaag A. Metabolic inflexibility is a common feature of impaired fasting glycaemia and impaired glucose tolerance. Acta Diabetol. 2011;48(4):349–53. - PubMed
    1. Coyle EF. Substrate utilization during exercise in active people. Am J Clin Nutr. 1995;61(4 Suppl):968S–79S. - PubMed
    1. Regensteiner JG, Sippel J, McFarling ET, Wolfel EE, Hiatt WR. Effects of non-insulin-dependent diabetes on oxygen consumption during treadmill exercise. Med Sci Sports Exerc. 1995;27(6):875–81. - PubMed

Publication types

MeSH terms