High-intensity exercise may trigger hypoglycemia counterregulatory response
medwireNews: Research presented at the 79th ADA Scientific Sessions in San Francisco, California, USA, suggests that high-intensity exercise can partially restore counterregulatory responses to hypoglycemia in people with impaired awareness of the condition.
Catriona Farrell, from the University of Dundee in the UK, explained that “[i]mpaired awareness of hypoglycemia (IAH) affects approximately 20–25% of all people with type 1 diabetes and is a major risk factor for severe hypoglycemia.”
She added that “the most important risk factor for IAH is prior exposure to hypoglycemia itself” because it “raises the threshold for triggering a counterregulatory response to subsequent hypoglycemia.”
Farrell continued: “We recently proposed that IAH may develop as a form of adaptive memory to repeated hypoglycemia; referred to as habituation.”
Farrell and team therefore investigated whether high-intensity exercise can be used as a “dishabituating stimulus” to restore counterregulatory responses to hypoglycemia.
Their study included 12 people with type 1 diabetes and IAH (Gold score ≥4, Modified Clark score ≥4, or DAFNE hypoglycemia awareness rating 2–3) who were randomly assigned to undergo one session of high-intensity exercise (4 x 30-second cycle sprints, with 2-minute recovery periods, achieving at least 90% of their maximum heart rate) or to 20 minutes of rest.
The next day participants underwent a 90-minute hyperinsulinemic hypoglycemic clamp study at 2.5 mmol/L with measurement of hormonal counterregulatory responses and hypoglycemia symptom scores. The test was repeated a minimum of 2 weeks later with participants crossing over to the other study arm.
Farrell reported that high-intensity exercise led to a significant 30% increase in the epinephrine response during hypoglycemia and a significantly higher mean epinephrine level relative to control (541.1 vs 418.8 pg/mL).
They also found that the participants experienced significantly more hypoglycemia symptoms during the clamp study after high-intensity exercise than they did after no exercise, with mean scores of 27.50 versus 24.25 on the Edinburgh Hypoglycemia scale.
Farrell concluded that the “findings are consistent with the hypothesis that IAH develops in people with [type 1 diabetes] as a habituated response and that introduction of a novel stressor can restore, at least partially, the [counterregulatory] response to hypoglycemia.”
Therefore, “dishabituation with high-intensity exercise may represent a novel treatment option for adults with type 1 diabetes and IAH,” he added.
By Laura Cowen
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