Insulin pump basal adjustment for exercise in type 1 diabetes: a randomised crossover study

Abstract

ANZCTR.org.au ACTRN12613000581763 FUNDING: Australian Diabetes Society, Hugh DT Williamson Foundation, Lynne Quayle Charitable Trust Fund.

Asymmetric changes in circulating insulin levels after an increase compared with a reduction in insulin pump basal rate in people with Type 1 diabetes

“…To our knowledge, there are no published studies demonstrating time to steadystate insulin after small clinically relevant basal rate reductions. Our observation of a decrease of only~8% in circulating insulin by 5 h after a 0.2-unit/h rate reduction is consistent with findings from pump studies which halved (19% fall by 3 h) [14] and ceased (70% fall by 3 h) [15] subcutaneous basal delivery. We suggest that the magnitude and direction of subcutaneous insulin basal rate changes not only determine the magnitude but also the time taken for these changes in insulin delivery to be translated into changes in circulating free insulin.…”

“…Although bolus pharmacokinetics are often used to inform insulin pump basal profiles in clinical practice, our findings show bolus data have limited applicability to routine clinical pump adjustments. Effects of rapid‐acting insulin analogue subcutaneous basal delivery changes ≥50% have been reported ; however, such rate changes are larger than those typically programmed within basal profiles in routine clinical care. After large basal rate increases, times to steady‐state insulin have been reported of between 2.5 and 8 h, with larger increments taking longer to reach steady state .…”

ISPAD Clinical Practice Consensus Guidelines 2018: Exercise in children and adolescents with diabetes

“…As mentioned previously, when an extremity (arm or leg) has been injected with insulin and is then exercised vigorously, the increased blood flow to the limb is likely to result in more rapid absorption and metabolic effect of the insulin . This effect likely occurs in other locations like the abdomen and buttock . This may be especially marked if the injection site is hypertrophied.…”

“…53 This effect likely occurs in other locations like the abdomen and buttock. 54 This may be especially marked if the injection site is hypertrophied. Nevertheless, a cyclist may achieve more consistent response by choosing to inject in an arm or the abdomen rather than a leg before an event.…”

Closed-loop glucose control in young people with type 1 diabetes during and after unannounced physical activity: a randomised controlled crossover trial

“…Several strategies have been suggested for limiting this risk, including recommendations on basal insulin adjustments and additional carbohydrate consumption, although these recommendations are inconsistent and based on limited evidence, particularly for the paediatric population [6][7][8]. The incorporation of intermittent highintensity sprints into moderate exercise is associated with less hypoglycaemia [9] and is recommended by the International Society for Paediatric and Adolescent Diabetes (ISPAD) as a possible strategy to minimise the risk for hypoglycaemia [10].…”