Basal-Bolus insulin adjustment & post-exercise nocturnal hypoglycaemia
Research type
Research Study
Full title
Influence of adjusting rapid-acting insulin aspart on post-exercise nocturnal hypoglycaemia in recreationally active people with type 1 diabetes on insulin degludec
IRAS ID
215409
Contact name
Richard M Bracken
Contact email
Sponsor organisation
R&D
Clinicaltrials.gov Identifier
U1111-1174-6676, Universal Trial Number (UTN)
Duration of Study in the UK
1 years, 0 months, days
Research summary
Research Summary
Regular exercise is promoted as part of a healthy lifestyle for people with type 1 diabetes (T1DM) but many patients fail to reach Government physical activity standards (e.g. Plotnikoff et al. 2005). Fears around loss of glycaemic control during and after exercise (Brazeau et al., 2008) are exacerbated by a lack of understanding of how different forms of exercise can exert different physiological demands. This leaves many patients (and their healthcare providers) with poor confidence of how to adjust exogenous insulins and/or carbohydrate consumption around physical activity so as to preserve blood glucose concentrations.
Several research studies that examined reductions to pre-exercise rapid-acting (bolus) insulin have demonstrated improved post-exercise glycaemia (De Feo et al., 2006, Grimm, 2005, Mauvais-Jarvis et al., 2003, Rabasa-Lhoret et al., 2001, West et al., 2010, 2011) but most were against a background of insulins glargine, NPH or ultralente. Furthermore, very recent work from our team (Campbell et al., 2014, 2013) demonstrate that further adjustment of rapid-acting insulin dose is necessary after completion of exercise, given the increase in muscle tissue glucose uptake that persists for many hours (and is independent of insulin pathways).
No research currently exists that explores the development of a glucose management strategy that includes newer insulin like insulin degludec as the basal insulin and investigates adjustments to a rapid acting insulin (e.g. insulin aspart) and pre-exercise fuel to reduce glycaemic variability during and following a bout of exercise in recreationally active type 1 diabetes patients – especially in the night-time period.
Summary of Results
To detail the extent and prevalence of post-exercise and nocturnal hypoglycemia following peri-exercise bolus insulin dose adjustments in individuals with type 1 diabetes (T1D) using multiple daily injections of insulins aspart (IAsp) and degludec (IDeg).
Methods and results: Sixteen individuals with T1D, completed a single-centred, randomised, four-period crossover trial consisting of 23-h inpatient phases. Participants administered either a regular (100%) or reduced (50%) dose (100%; 5.1 ± 2.4, 50%; 2.6 ± 1.2 IU, p < 0.001) of individualised IAsp 1 h before and after 45-min of evening exercise at 60 ± 6% V̇O2max. An unaltered dose of IDeg was administered in the morning. Metabolic, physiological and hormonal responses during exercise, recovery and nocturnal periods were characterised. The primary outcome was the number of trial day occurrences of hypoglycemia (venous blood glucose ≤ 3.9 mmol L -1). Inclusion of a 50% IAsp dose reduction strategy prior to evening exercise reduced the occurrence of in-exercise hypoglycemia (p = 0.023). Mimicking this reductive strategy in the post-exercise period decreased risk of nocturnal hypoglycemia (p = 0.045). Combining this strategy to reflect reductions either side of exercise resulted in higher glucose concentrations in the acute post-exercise (p = 0.034), nocturnal (p = 0.001), and overall (p < 0.001) periods. Depth of hypoglycemia (p = 0.302), as well as ketonic and counter-regulatory hormonal profiles were similar.
Conclusions: These findings demonstrate the glycemic safety of peri-exercise bolus dose reduction strategies in minimising the prevalence of acute and nocturnal hypoglycemia following evening exercise in people with T1D on MDI. Use of newer background insulins with current bolus insulins demonstrates efficacy and advances current recommendations for safe performance of exercise.
REC name
Wales REC 7
REC reference
16/WA/0394
Date of REC Opinion
20 Jan 2017
REC opinion
Further Information Favourable Opinion