Interrupting prolonged sitting with frequent short bouts of light-intensity activity in people with type 1 diabetes improves glycaemic control without increasing hypoglycaemia: The SIT-LESS randomised controlled trial

AbstractAimTo examine the impact of interrupting prolonged sitting with frequent short bouts of light‐intensity activity on glycaemic control in people with type 1 diabetes (T1D).Materials and MethodsIn total, 32 inactive adults with T1D [aged 27.9 ± 4.7 years, 15 men, diabetes duration 16.0 ± 6.9 years and glycated haemoglobin 8.4 ± 1.4% (68 ± 2.3 mmol/mol)] underwent two 7‐h experimental conditions in a randomised crossover fashion with >7‐day washout consisting of: uninterrupted sitting (SIT), or, interrupted sitting with 3‐min bouts of self‐paced walking at 30‐min intervals (SIT‐LESS). Standardised mixed‐macronutrient meals were administered 3.5 h apart during each condition. Blinded continuous glucose monitoring captured interstitial glucose responses during the 7‐h experimental period and for a further 48‐h under free‐living conditions.ResultsSIT‐LESS reduced total mean glucose (SIT 8.2 ± 2.6 vs. SIT‐LESS 6.9 ± 1.7 mmol/L, p = .001) and increased time in range (3.9‐10.0 mmol/L) by 13.7% (SIT 71.5 ± 9.5 vs. SIT‐LESS 85.1 ± 7.1%, p = .002). Hyperglycaemia (>10.0 mmol/L) was reduced by 15.0% under SIT‐LESS (SIT 24.2 ± 10.8 vs. SIT‐LESS 9.2 ± 6.4%, p = .002), whereas hypoglycaemia exposure (<3.9 mmol/L) (SIT 4.6 ± 3.0 vs. SIT‐LESS 6.0 ± 6.0%, p = .583) was comparable across conditions. SIT‐LESS reduced glycaemic variability (coefficient of variation %) by 7.8% across the observation window (p = .021). These findings were consistent when assessing discrete time periods, with SIT‐LESS improving experimental and free‐living postprandial, whole‐day and night‐time glycaemic outcomes (p < .05).ConclusionsInterrupting prolonged sitting with frequent short bouts of light‐intensity activity improves acute postprandial and 48‐h glycaemia in adults with T1D. This pragmatic strategy is an efficacious approach to reducing sedentariness and increasing physical activity levels without increasing risk of hypoglycaemia in T1D.