Effects of acute caffeine supplementation on reducing exercise-associated hypoglycaemia in individuals with Type 1 diabetes mellitus

AimTo determine the effects of acute caffeine ingestion on glycaemia during moderate to vigorous intensity aerobic exercise and in recovery in individuals with Type 1 diabetes. MethodsA total of 13 patients with Type 1 diabetes [eight women, five men: mean sd age 25.9 8.8 years, BMI 71.9 11.0 kg, maximal oxygen consumption 46.6 12.7 ml/kg/min, body fat 19.9 7.2%, duration of diabetes 14.4 10.1 years and HbA(1c) 55 +/- 8 mmol/mol (7.4 +/- 0.8%)] were recruited. Participants ingested capsules that contained gelatin or pure caffeine (6.0 mg/kg body mass) and performed afternoon exercise for 45 min at 60% maximal oxygen consumption on two separate visits with only circulating basal insulin levels. ResultsThe main finding was that a single caffeine dose attenuates the drop in glycaemia by 1.8 +/- 2.8 mmol/l compared with placebo intake during exercise (P=0.056). Continuous glucose monitoring data, however, showed that caffeine was associated with elevated glycaemia at bedtime after exercise, compared with placebo, but lower glucose concentrations in the early morning the next day. ConclusionsCaffeine intake should be considered as another strategy that may modestly attenuate hypoglycaemia in individuals with Type 1 diabetes during exercise, but should be taken with precautionary measures as it may increase the risk of late-onset hypoglycaemia.