Unstructured Physical Activity Lowers Glucose, but Increases Risk of Hypoglycemia in T1D

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A recent study published in Diabetes, Obesity and Metabolism provides insight into the relationship between unstructured physical activities and glucose control in individuals with type 1 diabetes. The findings show that while these activities can contribute to lower mean glucose concentrations, careful consideration, and additional measures are necessary to mitigate the associated risk of hypoglycemia.

The research involved an analysis of data from the ADREM trial, focusing on 18 adults (12 men) with an average age of 38 years with type 1 diabetes. Participants wore continuous glucose monitoring devices and accelerometers for 24 hours daily.

Days with structured exercise were excluded, as the investigation concentrated solely on unstructured physical activities. Statistical methods, including mixed-regression models, were employed to discern the associations between unstructured activities and various glucose parameters.

In the findings, investigators observed unstructured physical activities, irrespective of their intensity, were associated with a lower mean glucose concentration throughout the day and into the subsequent night. However, these activities were also linked to greater glucose variability and a higher risk of hypoglycemia that persisted until the next day.

Specifically, unstructured physical activity accounted for up to 19% of the variation in hypoglycemic risk, underscoring the clinical relevance of these findings. Investigators pointed out the role of light-intensity physical activity (LIPA), which demonstrated a delicate balance: a 113-minute increase in LIPA led to a significant drop in mean nocturnal glucose.

This association was reported as consistent regardless of when the activity occurred indicating the enduring impact of unstructured physical activities on glucose control.

When evaluating mean glucose concentration, results revealed significant associations with different forms of physical activity. During the same-day awake period, higher levels of active time (B, –0.35 [95% CI, −0.56 to −0.14]; P < .001), a greater step count (B, −0.41 [95% CI, −0.63 to −0.18]; P < .001), and increased moderate-to-vigorous physical activity (MVPA) (B, −0.33 [95% CI, −0.56 to −0.09]; P = .006) were all linked to a lower mean glucose concentration.

Similarly, more active time (B, −0.45 [95% CI −0.78 to −0.12]; P = .008) and LIPA (B, −0.49 [95% CI −0.85 to −0.12]; P = .009) were associated with lower mean glucose concentration during the subsequent night.

However, late-day active time and LIPA did not exhibit any significant associations with mean glucose concentration and no significant correlation was found between physical activity parameters and next-day mean glucose concentration.

The results also exhibited an almost twofold increased risk of hypoglycemia, highlighting the need for personalized management strategies tailored to individuals' specific activity patterns and glycemic profiles.

Higher levels of active time (OR, 1.56 [95% CI, 1.11-2.21]; P = .011) and a greater step count (OR, 1.55 [95% CI, 1.09-2.21]; P = .014) were associated with increased risks of hypoglycemia during the same-day awake period

Elevated active time (OR, 2.40 [95% CI, 1.46-3.96]; P = .001), step count (OR, 2.05 [95% CI, 1.30-3.21]; P = .002), MVPA (OR, 1.71 [95% CI, 1.07-2.74]; P = .024), and LIPA (OR, 1.88 [95% CI, 1.15-3.07]; P = .012), were all linked to higher risks of nocturnal hypoglycemia.

The risk of nocturnal hypoglycemia was also increased with higher early-day active time, step count, MVPA, and LIPA, as well as late-day active time and LIPA. Both active time and LIPA positively correlated with the occurrence of next-day hypoglycemia.

When examining glucose variability, the study found that more active time was associated with a higher coefficient of variation in the same-day and next-day awake periods. However, no significant correlations were observed between physical activity parameters and standard deviations of the same day, subsequent night, or the next day.

Engaging in unstructured physical activities, even those of low intensity and carried out in the morning and early afternoon, is linked to reduced average glucose levels throughout the day and night, the investigators concluded.

Because these activities also elevate the likelihood of experiencing hypoglycemia, particularly during the night, in these individuals the study stated the findings indicate that incorporating daily unstructured physical activities might enhance glucose management, as long as the risk of hypoglycemia is considered.

Reference

Drenthen, LCA, Ajie, M, Bakker, EA, et al. Daily unstructured physical activity affects mean glucose, occurrence of hypoglycaemia and glucose variability in people with type 1 diabetes. Diabetes Obes Metab. 2023; 1-4. doi:10.1111/dom.15277