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.