Effects of Moderate-to-Vigorous Intensity Physical Activity on Overnight and Next-Day Hypoglycemia in Active Adolescents With Type 1 Diabetes

Abstract

OBJECTIVEPhysical activity (PA) provides many benefits to adolescents with type 1 diabetes; however, these individuals tend to have lower fitness and PA levels than their disease-free counterparts. The purpose of this study was to examine the acute temporal associations between moderate-to-vigorous intensity PA (MVPA) and hypoglycemia (continuous glucose monitor [CGM] reading ≤70 mg/dL).RESEARCH DESIGN AND METHODSNineteen participants (53% females) 14–20 years old with type 1 diabetes were recruited. Participant fitness was evaluated via indirect calorimetry using a maximal exercise test; body composition was measured using air displacement plethysmography. An accelerometer was worn continuously (3–5 days) and acceleration data used to estimate MVPA (minutes per day). Blood glucose values were simultaneously tracked using CGM. Controlling for sex, percent body fat (%BF), fitness, and concurrent MVPA, the likelihood of nighttime and next-day hypoglycemia due to MVPA was examined using logistic regression.RESULTSParticipants were of average fitness (females: 43.9 mL/kg/min; males: 49.8 mL/kg/min) and adiposity (females: 26.2%; males: 19.2%); 63.2% met the U.S. federal guideline of accumulating 60 min/day of MVPA. Hypoglycemia was 31% more likely in those who accumulated 30 min/day more MVPA in the previous afternoon than those with less (95% CI 1.05–1.63; P = 0.017).CONCLUSIONSThe results suggest that participating in afternoon MVPA increases the risk of overnight and next-day hypoglycemia, independent of sex, %BF, fitness, and concurrent MVPA. While promoting PA as a healthy behavior, it is important to educate adolescents with type 1 diabetes on prevention of hypoglycemia following PA.

A Systematic Review of Physical Activity and Exercise on Physiological and Biochemical Outcomes in Children and Adolescents With Type 1 Diabetes

“…However, three studies found no association between PA and glycemic control (Kalweit, Briers, & Olorunju, ; Keel et al., ; Mosso et al., ). For blood glucose regulation, in the case‐control study with 200 adolescents who were instructed to cross the maximum distance in meters following the 6‐min walk test, a positive effect of PA on blood glucose without increasing the risk for hypoglycemia was noted (Jegdic et al., ; Metcalf et al., ). Three cross‐sectional studies observed a significant positive association between reported PA and HDLs and a significant negative association with LDLs (Heyman et al., ; Mohammed et al., ; Parthasarathy et al., ).…”

Physical Activity and Type 1 Diabetes

“…The risk of overnight and next-day hypoglycemia is particularly problematic if moderate to vigorous exercise is undertaken in the afternoon or early evening. 25,26 Late-onset hypoglycemia following exercise increases with the duration of exercise and the fitness of the exercisers, and activities lasting 90 to 120 minutes double the risk of hypoglycemia in adolescents and young adults. 26 …”

Adjusting Insulin Delivery to Activity (AIDA) clinical trial: Effects of activity‐based insulin profiles on glucose control in children with type 1 diabetes

“…An appropriately powered randomized control trial comparing control achieved in subjects managed with activity monitor and semi‐automated basal adjustment vs standard CGM‐enabled pump therapy is needed to confirm whether glucose control is improved. Sensor‐enabled insulin pumps with low glucose suspend, or closed‐loop systems, may eventually eliminate the need to reduce nighttime basal rates following high activity days; however, it may not be feasible or advisable for every patient to be on these systems all the time. Lastly, integration of activity data into closed‐loop algorithms, which could feasibly be done if an accelerometer were integrated into the insulin pump, may also help optimize glycemic control.…”

“…Despite these advances, many patients continue to use standard insulin pumps with no automation, and the opportunity to optimize how these pumps are configured remains. This is particularly true in relation to varying insulin requirements associated with physical activity, as exercise is known to be associated with higher risk of overnight and even next‐day‐hypoglycemia in children and adolescents with T1DM . Although the DirectNet Study Group showed reductions in hypoglycemia with basal rate suspension, the suspensions were only initiated in response to low glucose or impending low glucose .…”