Physical activity may help address hyperglycemia in type 1 diabetes

Patients with type 1 diabetes may be able to address hyperglycemia with bouts of physical activity, according to a recent study.

Researchers performed a retrospective analysis using data from two cohort studies that involved 1,546 physical activity bouts, 10 to 30 minutes in duration, by 482 patients whose glucose levels were above 10 mmol/L (180 mg/dL). Each bout of physical activity was matched to a nonphysical activity period within the same patient for starting glucose level, glucose rate of change, insulin on board, and glucose variability. The study's primary outcome was change in glucose level from onset of physical activity to 20 minutes after the activity, and secondary outcomes were predictors of glucose response and rates of hypoglycemia. The results were published Oct. 8 by Diabetic Medicine.

Physical activity led to a mean glucose change of −2.2 mmol/L (−39.6 mg/dL) (P<0.001), compared with 0.3 mmol/L (5.4 mg/dL) (P<0.001) during matched nonphysical activity periods (mean difference, −1.9 mmol/L [−34.2 mg/dL]; P<0.0001). Median length of physical activity was 23 minutes (interquartile range, 20 to 30 minutes). No significant differences were seen by age or by physical activity type or intensity. Glucose rate of change, starting glucose level, glucose variability, duration, and insulin on board were the strongest predictors of glucose change induced by physical activity. Risk for physical activity-induced hypoglycemia was below 2%.

The researchers noted that their results could have been affected by residual confounding and that physical activity was self-reported in one cohort and measured by device in the other, among other limitations. “This study provides strong evidence that 10- to 30-min bouts of PA [physical activity] significantly accelerate glucose lowering in people with type 1 diabetes compared to matched periods without PA. …These findings demonstrate that even relatively brief periods of PA, using any form or intensity, can serve as an effective and practical strategy to rapidly lower elevated glucose levels,” they wrote.

In a separate commentary published Nov. 5 by Diabetic Medicine, the same authors explained that their findings support a simple heuristic, called “20 by 2” in mmol/L or “20 by 40” in mg/dL, that can be used to reframe physical activity as an acute, real-time adjunct to insulin for hyperglycemia.

“Reframing physical activity as a powerful, real-time glycaemic optimiser—rather than only a long-term health strategy—positions it as a safe, zero-cost therapy that, in the era of continuous glucose monitoring, delivers instant feedback and reinforces a virtuous cycle of activity driving better control,” they wrote. “Future research should also explore whether short bouts of activity can be used pre-emptively to prevent post-prandial glucose excursions, in addition to their corrective role when glucose is elevated.”