Short, frequent, light‐intensity walking activity improves postprandial vascular‐inflammatory biomarkers in people with type 1 diabetes: The SIT‐LESS randomized controlled trial

AbstractAimTo examine the effect of interrupting prolonged sitting with short, frequent, light‐intensity activity on postprandial cardiovascular markers in people with type 1 diabetes (T1D).Materials and MethodsIn a randomized crossover trial, 32 adults with T1D (mean ± SD age 28 ± 5 years, glycated haemoglobin 67.9 ± 12.6 mmol/mol, 17 women) completed two 7‐h laboratory visits separated by >7 days. Participants either remained seated for 7 h (SIT) or interrupted sitting with 3‐min bouts of self‐paced walking at 30‐min intervals commencing 1 h after each meal (SIT‐LESS). Physical activity, insulin regimen, experimental start times, and meal consumption were standardized during each arm. Plasma levels of interleukin (IL)‐1β, tumour necrosis factor (TNF)‐α, plasminogen activator inhibitor (PAI)‐1 and fibrinogen were sampled at baseline, 3.5 and 7 h, and assessed for within‐ and between‐group effects using a repeated measures ANOVA. The estimated glucose disposal rate was used to determine the insulin resistance status.ResultsVascular‐inflammatory parameters were comparable between SIT and SIT‐LESS at baseline (p > .05). TNF‐α, IL‐1β, PAI‐1 and fibrinogen increased over time under SIT, whereas these rises were attenuated under SIT‐LESS (p < .001). Specifically, over the 7 h under SIT, postprandial increases were detected in TNF‐α, IL‐1β, PAI‐1 and fibrinogen (+67%, +49%, +49% and +62%, respectively; p < .001 for all). Conversely, the SIT‐LESS group showed no change in IL‐1β (−9%; p > .50), whereas reductions were observed in TNF‐α, PAI‐1 and fibrinogen (−22%, −42% and −44%, respectively; p < .001 for all). The intervention showed enhanced effects in insulin‐resistant individuals with T1D.ConclusionsInterrupting prolonged sitting with light‐intensity activity ameliorates postprandial increases in vascular‐inflammatory markers in T1D.Trial RegistrationThe trial was prospectively registered (ISRCTN13641847).