Enhancing Type 1 Diabetes Self-Management: Investigating the Role of Physical Activity and Sedentary Behaviours in Glucose Control

Physical activity (PA), sedentary behaviour (SB), and interruptions to prolonged sitting may influence glucose control in adults with type 1 diabetes (T1D). This thesis investigates their impact using experimental studies. One study explored attitudes and barriers to exercise in adults with T1D, stratified by insulin resistance (IR), using estimated glucose disposal rate (eGDR) as a marker. The study found that hypoglycaemia was the main concern for those with IR, whereas non-glycaemic factors were the main barriers for those without IR. A systematic review and meta-analysis showed that adults with T1D are more inactive and sedentary than guidelines recommended (Part A). It also found that acute exercise led to short-term reductions in plasma glucose concentrations, but chronic exercise had no significant impact on glycated haemoglobin (HbA1c) levels or fasting plasma glucose concentrations (Part B). A 14-day observational study using continuous glucose monitoring (CGM) indicated that moderate-intensity PA was associated with higher blood glucose concentrations, while vigorous-intensity PA improved time in range (TIR). Finally, a randomised controlled trial (RCT), demonstrated that interrupting prolonged sitting with short bouts of low-intensity walking improved glucose control, increasing TIR, and reducing hyperglycaemia without raising hypoglycaemia risk in T1D. These findings highlight the importance of reducing sedentary time and incorporating activity breaks to enhance glucose control in T1D, supporting the development of future long-term interventions.