Different frequencies of active interruptions to sitting have distinct effects on 22 h glycemic control in type 2 diabetes

BACKGROUND & AIMS

Whether the frequency of interruptions to sitting time involving simple resistance activities (SRAs), compared to uninterrupted sitting, differentially affected 22 h glycemic control in adults with medication-controlled type 2 diabetes (T2D).

METHODS & RESULTS

Twenty-four participants (13 men; mean ± SD age 62 ± 8 years) completed three 8 h laboratory conditions: SIT: uninterrupted sitting; SRA3: sitting interrupted with 3 min of SRAs every 30 min; and, SRA6: sitting interrupted with 6 min of SRAs every 60 min. Flash glucose monitors assessed glycemic control over a 22 h period. No differences were observed between conditions for overall 22 h glycemic control as measured by AUC_total, mean glucose and time in hyperglycemia. During the 3.5 h post-lunch period, mean glucose was significantly lower during SRA6 (10.1 mmol·L^-1, 95%CI 9.2, 11.0) compared to SIT (11.1 mmol·L^-1, 95%CI 10.2, 12.0; P = 0.006). Post-lunch iAUC_net was significantly lower during SRA6 (6.2 mmol·h·L^-1, 95%CI 3.3, 9.1) compared to SIT (9.9 mmol·h·L^-1, 95%CI 7.0, 12.9; P = 0.003). During the post-lunch period, compared to SIT (2.2 h, 95%CI 1.7, 2.6), time in hyperglycemia was significantly lower during SRA6 (1.5 h, 95%CI 1.0, 1.9, P = 0.001). Nocturnal mean glucose was significantly lower following the SRA3 condition (7.6 mmol·L^-1, 95%CI 7.1, 8.1) compared to SIT (8.1 mmol·L^-1, 95%CI 7.6, 8.7, P = 0.024).

CONCLUSIONS

With standardized total activity time, less-frequent active interruptions to sitting may acutely improve glycemic control; while more-frequent interruptions may be beneficial for nocturnal glucose in those with medication-controlled T2D.

A low-carbohydrate protein-rich bedtime snack to control fasting and nocturnal glucose in type 2 diabetes: A randomized trial

In type 2 diabetes, liver insulin resistance and excess hepatic glucose production results in elevated fasting glucose. A bedtime snack has been recommended to improve fasting glucose, yet there is little evidence supporting this recommendation. Moreover, the optimal composition of a bedtime snack is unknown.

PURPOSE

To determine whether a low-carbohydrate protein-rich bedtime snack (Egg) could reduce fasting plasma glucose levels in people with type 2 diabetes when compared to a high-carbohydrate protein-rich bedtime snack (Yogurt) or a No Bedtime Snack condition. Secondary outcomes included glucose control assessed by continuous glucose monitoring (CGM) and fasting insulin sensitivity markers.

METHODS

Using a randomized crossover design, participants with type 2 diabetes (N = 15) completed three separate isocaloric conditions: i) Egg, ii) Yogurt, and iii) No Bedtime Snack, each lasting three days. CGM was collected throughout and duplicate fasting blood samples were obtained on the morning of day 4 in each condition.

RESULTS

Fasting plasma glucose (P = 0.04, d = 0.68), insulin (P = 0.04, d = 0.45), and nocturnal glucose (P = 0.02, d = 0.94) were significantly lower, and quantitative insulin sensitivity check index (QUICKI; P = 0.003) was improved, in the Egg compared to the Yogurt bedtime snack. There were no significant differences between either bedtime snack and No Bedtime Snack.

CONCLUSION

In the short-term, a low-carbohydrate bedtime snack (Egg) lowered fasting glucose and improved markers of insulin sensitivity when compared to a high-carbohydrate protein-matched bedtime snack (Yogurt). However, consuming a low- or high-carbohydrate bedtime snack did not appear to lower fasting glucose compared to consuming an isocaloric diet with no bedtime snack. CLINICAL TRIAL REGISTRY: clinicaltrials.gov (NCT03207269).