Continuous exercise in hypoxia improved glycemic control in type 2 diabetes

Mackenzie R. J Clin Endocrinol Metab. 2012;doi:10.1210/jc.2011-2829.

Issue: March 2012

Using hypoxia exercise in the treatment of type 2 diabetes may be an effective way to acutely and moderately control glucose, according to data from a recent study.

“Current guidelines suggest that health benefits can be gained when patients with type 2 diabetes spend 30 minutes exercising each day, but published data have failed to show intermittent exercise to be effective,” study researcher Richard Mackenzie, PhD, of the University of Westminster in London, said in a press release. “Here we have shown that intermittent exercise seems to improve the glucose profiles of type 2 diabetics with a greater positive effect when intermittent exercise is combined with mild hypoxia, similar to doing the exercise at altitudes of 2,500 meters.”

Researchers tested the efficacy of exercise with and without hypoxia on acute- and moderate-term glucose kinetics and insulin sensitivity in patients with type 2 diabetes. According to background information in the study, “hypoxia and muscle contraction stimulate glucose transport activity in vitro.”

Eight men with type 2 diabetes were included in the study, which was conducted at a university research center in the United Kingdom.

Participants completed 60 minutes of continuous exercise at 90% lactate threshold in hypoxia (HyEx60); intermittent exercise at 120% lactate threshold, separated by 5:5 minute periods of passive recovery in hypoxia (Hy5:5); and intermittent exercise (5.5 minutes) at 120% lactate threshold in normoxia. The researchers tested glucose appearance and disappearance. Twenty-four and 48 minutes after exercise, researchers measured homeostasis models of insulin resistance (HOMA_IR), fasting insulin resistance index (FIRI) and beta-cell function.

From baseline, glucose disappearance increased (1.85 mg/kg Χ min^-1) compared with 24 hours after HyEx60 (2.01 min/kg 3 min^-1; P=.031). There was no difference in glucose disappearance observed in either Hy5:5 (P=.064) or normoxia (P=.385). HOMA_IR improved from baseline after Hy5:5 [d 1, 6.20 (0.40)] when compared with day 2 [4.83 (0.41); P=.0013].

Both HOMA_IR and FIRI improved in the 24 hours (HOMA_IR P=.002; FIRI P=.003); this was true 48 hours after HyEx60 (HOMA_IR P=.028; FIRI P=.034).

“A combination of moderately reduced oxygen levels with exercise can significantly improve the body’s ability to respond to insulin in type 2 diabetic patients over exercise alone,” Mackenzie said. “Our findings suggest the possible use of exercise with mild hypoxic for the treatment of type 2 diabetes.”

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