Metabolic implications when employing heavy pre- and post-exercise rapid-acting insulin reductions to prevent hypoglycaemia in Type 1 diabetes patients: a randomised clinical trial

Research output: Contribution to journalArticle

  • Matthew Campbell
  • Mark Walker
  • Michael Trenell
  • Stephen Luzio
  • Gareth Dunseath
  • Daniel Tuner
  • Richard Bracken
  • Stephen Bain
  • Mark Russell
  • Emma Stevenson
  • Dan West
Original languageEnglish
Article numbere97143
JournalPLoS ONE
Issue number5
Publication statusPublished - 2014
Externally publishedYes
Aim: To examine the metabolic, gluco-regulatory-hormonal and inflammatory cytokine responses to large reductions in rapid-acting insulin dose administered prandially before and after intensive running exercise in male type 1 diabetes patients. Methods: This was a single centre, randomised, controlled open label study. Following preliminary testing, 8 male patients (24±2 years, HbA1c 7.7±0.4%/61±4 mmol.l−1) treated with insulin's glargine and aspart, or lispro attended the laboratory on two mornings at ∼08:00 h and consumed a standardised breakfast carbohydrate bolus (1 g−1BM; 380±10 kcal) and self-administered a 75% reduced rapid-acting insulin dose 60 minutes before 45 minutes of intensive treadmill running at 73.1±0.9% VO2peak. At 60 minutes post-exercise, patients ingested a meal (1 g−1BM; 660±21 kcal) and administered either a Full or 50% reduced rapid-acting insulin dose. Blood glucose and lactate, serum insulin, cortisol, non-esterified-fatty-acids, β-Hydroxybutyrate, and plasma glucagon, adrenaline, noradrenaline, IL-6, and TNF-α concentrations were measured for 180 minutes post-meal. Results: All participants were analysed. All glycaemic, metabolic, hormonal, and cytokine responses were similar between conditions up to 60 minutes following exercise. Following the post-exercise meal, serum insulin concentrations were lower under 50% (p<0.05) resulting in 75% of patients experiencing hyperglycaemia (blood glucose ≥8.0 mmol.l−1; 50% n = 6, Full n = 3). β-Hydroxybutyrate concentrations decreased similarly, such that at 180 minutes post-meal concentrations were lower than rest under Full and 50%. IL-6 and TNF-α concentrations remained similar to fasting levels under 50% but declined under Full. Under 50% IL-6 concentrations were inversely related with serum insulin concentrations (r = −0.484, p = 0.017). Conclusions: Heavily reducing rapid-acting insulin dose with a carbohydrate bolus before, and a meal after intensive running exercise may cause hyperglycaemia, but does not augment ketonaemia, raise inflammatory cytokines TNF-α and IL-6 above fasting levels, or cause other adverse metabolic or hormonal disturbances.

    Research areas

  • blood sugar, diabetic endocrinology


  • Russell_PLoS_Metabolic_implications_2014

    Rights statement: © 2014 Campbell et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

    Final published version, 586 KB, PDF document

External organisations

  • Northumbria University
  • Newcastle University
  • Swansea University

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