Can physical activity affect glucose levels variations in patients with diabetes?

This study evaluated the effect of physical activity interventions on glycemic variability (GV; glucose levels variations) in patients with diabetes. The data showed that physical activity was associated with significantly reduced GV in these patients.

Physical activity has been shown to reduce hemoglobin A1c (the average blood glucose over 2-3 months; HbA1c), and fasting plasma glucose (plasma glucose levels after fasting for at least 8 hours; FPG). However, it is unclear whether physical activity can increase the risk of patients developing abnormally low blood glucose (hypoglycemia) or high blood glucose (hyperglycemia).

Glycemic variability (GV; fluctuations in glucose measurements over time) may lead to diabetes complications. Newer glucose monitoring techniques like continuous glucose monitoring (CGM) may be good indicators of GV. Possible measures include time in range (TIR; the amount of time spent in the targeted blood glucose levels range), time above range (TAR; the amount of time spent above the targeted blood glucose range), time below range (TBR; the amount of time below the targeted blood glucose range) and mean amplitude of glycemic excursion (MAGE; blood glucose changes that exceed standard changes, which are a measure of blood glucose instability). There is a need to evaluate whether physical activity has any effects on these GV measurements in patients with diabetes.

This review analyzed 13 trials that included patients with diabetes. Patients were assigned to a physical activity treatment group or a control group. Studies had exercise durations of 24 hours to 12 weeks. TIR, TAR, TBR, and MAGE were measured in patients.

Patients with diabetes that had physical activity treatment showed significantly better TIR, decreased MAGE, and decreased TAR, compared to those that received a control intervention. Higher body mass index (BMI; a measurement of weight in relation to height) levels at the beginning of the study in patients were linked to a greater decrease in MAGE. Lower HbA1c levels at the beginning of the study were linked to a greater increase in TBR during physical activities.

The study concluded that physical activity significantly reduced GVy in patients with diabetes and may be more beneficial to those with higher BMI.

The sample size for patients with type 1 diabetes was small. Different types of physical activity of varied duration were used and may affect interpretations.