National Institute for Social Care and Health Research
(NISCHR)
Published Paper
Lead Researcher: Dr Richard Bracken
Project title: Factors pertaining to the occurrence of hypoglycaemia in exercising
type 1 diabetes patients
Paper title: A combined insulin reduction and carbohydrate feeding strategy 30 min
before running best preserves blood glucose concentration after exercise through
improved fuel oxidation in type 1 diabetes mellitus. Journal of Sports Sciences. 29(3)
279-289
Authors: West D, Stephens J.W., Luzio, S., Kilduff, L., Still, R, Bain, S.C. and
Bracken, R.M. (2011).
Abstract:
In this study, we examined the glycaemic and fuel oxidation responses to alterations in the
timing of a low glycaemic index carbohydrate and 75% reduced insulin dose, prior to running,
in type 1 diabetes individuals. After carbohydrate (75 g isomaltulose) and insulin
administration, the seven participants rested for 30 min, 60 min, 90 min or 120 min (conditions
30MIN, 60MIN, 90MIN, and 120MIN, respectively) before completing 45 min of running at
70% peak oxygen uptake. Carbohydrate and lipid oxidation rates were monitored during
exercise and blood glucose and insulin were measured before and for 3 h after exercise. Data
were analysed using repeated-measures analysis of variance. Pre-exercise blood glucose
concentrations were lower for 30MIN compared with 120MIN (P < 0.05), but insulin
concentrations were similar. Exercising carbohydrate and lipid oxidation rates were lower and
greater, respectively, for 30MIN compared with 120MIN (P < 0.05). The drop in blood glucose
during exercise was less for 30MIN (3.7 mmol · l(-1), s(x) = 0.4) compared with 120MIN (6.4
mmol · l(-1), s(x) = 0.3) (P = 0.02). For 60 min post-exercise, blood glucose concentrations
were higher for 30MIN compared with 120MIN (P < 0.05). There were no cases of
hypoglycaemia in the 30MIN condition, one case in the 60MIN condition, two in the 90MIN
condition, and five in the 120MIN condition. In conclusion, a low glycaemic index
carbohydrate and reduced insulin dose administered 30 min before running improves preand post-exercise blood glucose responses in type 1 diabetes.
Journal Link:
http://www.tandfonline.com/doi/abs/10.1080/02640414.2010.531753?url_v
er=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed