Exercise‐induced Hypoglycaemia and Subcutaneous Insulin Infusion

Abstract

To assess whether exercise-induced hypoglycaemia could be prevented by interruption of insulin infusion (3 h) we studied diabetic patients treated with continuous subcutaneous insulin infusion (CSII). The studies were performed in 7 insulin-dependent diabetics (aged 31.4 +/- 4.8 (mean +/- SD) years, duration of diabetes 16.9 +/- 5.4 years), after an overnight fast and in the afternoon, 4 h after the last pre-meal bolus injection (exercise and control period). Bicycle exercise (45 min at 60% of maximum oxygen consumption) was started 30 min after the insulin infusion was stopped. During exercise there was a more pronounced decline in blood glucose in the afternoon (2.2 +/- 0.3 mmol/l, mean +/- SEM) than in the morning (1.4 +/- 0.4 mmol/l) (p less than 0.01). This corresponded to higher mean levels of free insulin during exercise in the afternoon (20 +/- 4.5 mU/I vs 12.0 +/- 1.0 mU/l, in the morning). Interruption of insulin delivery for 3 h resulted in a moderate increase of blood glucose, a gradual decrease of free insulin, and a moderate increase in free fatty acids and beta-hydroxybutyrate. During exercise in the afternoon 3 diabetics suffered from symptomatic hypoglycaemia (BG less than 2.8 mmol/l). In contrast with most of the other patients they showed no decline of free insulin during exercise. Thus even after interruption of basal rate insulin infusion moderate postprandial exercise may lead to hypoglycaemia if there is relative hyperinsulinism.

Insulin Pump Therapy Is Associated with Less Post-Exercise Hyperglycemia than Multiple Daily Injections: An Observational Study of Physically Active Type 1 Diabetes Patients

“…Conversely, Admon et al 12 found similar rates of hypoglycemia during 45 min of moderate aerobic activity performed 2 h after breakfast whether basal insulin was suspended or not. Where afternoon exercise was performed (as was the case in our study), Edelmann et al 11 found that if basal insulin was suspended for 3 h (starting 30 min prior to exercise), it was insufficient to prevent hypoglycemia during exercise. In contrast, Tsalikian et al 8 found that suspending basal insulin at the start of exercise limited the frequency of hypoglycemia during the activity (16% vs. 43% in pump off vs. pump on trials) but resulted in more post-exercise hyperglycemia (27% vs. 4%).…”

“…On the other hand, too aggressive a reduction in basal and/or bolus insulin, as may occur with pump suspension, may contribute to exercise-associated hyperglycemia, particularly in the postexercise period. [7][8][9] A limited number of studies have examined the glycemic response to exercise in patients with type 1 diabetes receiving insulin by constant infusion, 8,[10][11][12] although few have actually compared CSII versus MDI. Sonnenberg et al 10 found that, when performing 60 min of moderate aerobic exercise in the morning 90 min after breakfast, hypoglycemia occurred in more than half of their CSII participants unless the pre-meal bolus was decreased by 50% and the basal insulin infusion was suspended during exercise.…”

Insulin‐based strategies to prevent hypoglycaemia during and after exercise in adult patients with type 1 diabetes on pump therapy: the DIABRASPORT randomized study

“…A more detailed analysis of the afternoon post‐exercise shows that the best option for exercise at 50% VO 2 max 3 h after lunch is 80% BR reduction throughout exercise and the ensuing 2 h. This approach offers an intermediate solution between reducing BR by 50% before exercise, as recommended by some authors and stopping the pump, which has also been proposed . For exercise at 75% VO 2 max, the best option is to stop the pump temporarily during exercise, which reflects fairly well the wish of certain patients to remove their pump.…”

“…reducing BR by 50% before exercise, as recommended by some authors [4,10,[17][18][19][20] and stopping the pump, which has also been proposed [21,22]. For exercise at 75% VO 2 max, the best option is to stop the pump temporarily during exercise, which reflects fairly well the wish of certain patients to remove their pump.…”

Diabetes and exercise.

“…Studies on continuous subcutaneous insulin infusion have shown that reducing the action of the pump by 50% before exercise, similar to multiple component regimens, prevents hypoglycaemia. [29][30][31] LISPRO Lispro is a rapid acting insulin analogue which has recently been developed, particularly for injection immediately before a meal. Its rapid absorption and short duration of action provide several advantages, and, although reports on Lispro and exercise are limited, the use of a shorter acting analogue will probably allow a greater degree of flexibility and the ability to accommodate short term planning or unexpected exercise.…”