ClinicalTrials.gg
CompletedNCT02068638CARBEX1Updated Aug 10, 2016

Impact of Physical Activity on Blood Glucose Stability and Energy Stores in Individuals With Type 1 Diabetes

An interventional study of IHE first, CONT second and CONT first, IHE second in Type 1 Diabetes Mellitus, Exercise and Hypoglycemia, sponsored by Insel Gruppe AG, University Hospital Bern. Completed at 1 site in Switzerland. Open to male participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2016-08-10.

Sponsored by Insel Gruppe AG, University Hospital Bern · Not applicable, Interventional, and Supportive care

Phase
Not applicable
Study type
Interventional
Enrollment
27
Allocation
Randomized
Ages
18 Years to 35 Years
Sex
Male
01

Study summary

Whereas physical activity clearly results in improvements in glycemic control in type 2 diabetes, in individuals with type 1 diabetes (T1DM) the impact of exercise on blood sugar control is more complex. In type 1 diabetes T1DM the inability to reduce exogenous insulin levels during exercise is a key factor that contributes to an increased risk of exercise-induced hypoglycemia. Since rapid adaptation of insulin dosage may be especially difficult in patients on a multiple daily injection regimen, alternative strategies are required to improve exercise-associated glucose stability. There is increasing evidence that the combination of steady state continuous low to moderate intensity exercise with short bursts of high intensity exertion (eg in the form of sprints) is an effective, well tolerated, novel strategy to prevent exercise-related hypoglycemia. A further promising option to stabilize blood sugar levels during and after exercise may be the ingestion of fructose in addition to glucose in form of a sport drink.

Read the detailed description

Background

Regular physical activity enhances insulin sensitivity in both healthy subjects and patients with diabetes mellitus. However, while the effects of physical activity on glucose control are undoubtedly beneficial in patients with type 2 diabetes, exercise can cause major disturbances in blood glucose levels in type 1 diabetic individuals. Hypoglycemia is a common complication in patients with T1DM engaging in endurance activities such as running and cycling. So far there are limited strategies suggested to improve exercise-related blood sugar self-management. Current recommendations focus on variation in timing and dosage of insulin administration and adjustments in carbohydrate intake. Since rapid adaptation of insulin dosage may be difficult, alternative strategies to improve exercise-related glucose stability are required. Increasing evidence suggests that intermittent high intensity exercise (IHE), by triggering a counterregulatory hormone response, may counter-balance the risk of exercise-associated hypoglycemia. However, previous studies investigating IHE in T1DM were limited by heterogeneous study populations, comparably short exercise protocols, and deficits in standardization procedures. In addition, a comprehensive assessment of the underlying fuel metabolism has not been performed so far. As a consequence, the results remain controversial and their interpretation as well as applicability are restricted.

A further alternative strategy to maintain stable glycemia during exercise may be deduced from recent studies in non-diabetic individuals suggesting that the combined ingestion of fructose and glucose during exercise provides the liver with an increased amount of gluconeogenic precursors, thereby reducing consumption of endogenous glycogen stores.Moreover, conversion of fructose into glucose and lactate may provide constant and efficient fuel for working muscles. However, studies assessing the impact of fructose ingestion during exercise in patients with T1DM have not been performed so far.

Objective

The investigators aim to assess the impact of two novel non-pharmaceutical and easily feasible approaches on exercise-related blood glucose stability and its underlying exercise-related fuel metabolism in patients with T1DM.

Substudy A will assess the influence on exercise-related glycemia and fuel metabolism of an IHE protocol compared to an iso-energetic continuous exercise (CONT). It will be investigated whether individuals reach more stable blood glucose levels when engaging in IHE compared to CONT.

Substudy B will investigate whether fueling the patients with a mixed oral 1:1 glucose-fructose carbohydrate solution will maintain glucose values within a more stable range when compared to carbohydrate supplementation by glucose alone.

Methods

Blood glucose levels, counterregulatory hormones, metabolites such as lactate and free fatty acids as well as inflammatory biomarkers will be assessed by regular blood samplings. By means of oral and intravenously given stable isotopes (U-13 C glucose and 2H glucose) exercise-related glucose kinetics will be investigated. Exercise-induced glycogen consumption will be measured using magnetic resonance spectroscopy technology. Late glycemic excursions will be recorded by continuous glucose monitoring systems.

In order to validate 13C magnetic resonance spectroscopy (MRS) measurement of hepatic and myocellular glycogen content a pre-study involving 10 patients and an equal number of matched healthy controls will be performed (validation and reproducibility study).

02

Conditions studied

  • Type 1 Diabetes Mellitus
  • Exercise
  • Hypoglycemia
  • Carbohydrate Metabolism

Keywords

  • exercise
  • isotope labeling, stable
  • spectroscopy, magnetic resonance
  • monitoring, home blood glucose
  • hormones
03

In context

Diabetes Mellitus, Type 1

3,614 studies on the registry are indexed under Diabetes Mellitus, Type 1; 586 are open to participants now.

This study's enrollment of 27 is below the median of 40 across 2,718 interventional studies indexed under Diabetes Mellitus, Type 1.

Browse Diabetes Mellitus, Type 1 studies →

Lead sponsor

Insel Gruppe AG, University Hospital Bern is the lead sponsor of 737 studies on the registry; 178 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 35 Years
Sexes eligible
Male
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Male
  • Aged 18 to 35 years
  • Diabetes mellitus duration for at least 5 years
  • No change in insulin regimen for at least 3 months prior to the study
  • Under acceptable to good metabolic control
  • Normal insulin sensitivity
  • Regular physical activity
  • BMI in the range of 18-25 kg/m2
  • Written informed consent

Exclusion criteria

Exclusion Criteria

  • Diabetes-related complications (macro and microvascular)
  • Anemia (hemoglobin concentration \<130g/l)
  • Abnormal thyroid function
  • Dyslipidemia
  • Major depression, psychosis and other severe personality disorders, claustrophobia
  • Active neoplasia
  • Contraindications to exposure to a 3 T magnetic field
  • Abnormal liver or renal function
  • Smoking, drug abuse, or daily alcohol consumption >60g
  • Participation in another study
  • Medication other than insulin
05

Study design

Phase
Not applicable
Primary purpose
Supportive care
Allocation
Randomized
Intervention model
Crossover assignment
Masking
None (open label)
Enrollment
27 participants (actual)

Study arms

  • Experimental
    IHE first, CONT second, CSII and MDI therapy

    IHE: intermittent high intensity exercise: integration of 10 s maximal sprints every 10 minutes in a continuous low to moderate intensity exercise of 90 minutes CONT (occurring after a washout period of 2-8 weeks): continuous moderate intensity exercise of 90 minutes

    Procedure: IHE first, CONT second

  • Experimental
    CONT first, IHE second,CSII and MDI therapy

    CONT: continuous moderate intensity exercise of 90 minutes. IHE (occurring after a washout period of 2-8 weeks): intermittent high intensity exercise: integration of 10 s maximal sprints every 10 minutes in a continuous low to moderate intensity exercise of 90 minutes

    Procedure: CONT first, IHE second

  • Experimental
    GLU first, GLUFRU second, CSII and MDI therapy

    GLU: ingestion of a 6% carbohydrate solution (consisting of 100 g glucose dissolved in 1000 ml tap water) over a continuous moderate exercise of 90 minutes. GLU FRU (occurring after a washout period of 2-8 weeks): ingestion of a 20% carbohydrate solution (consisting of 100 g glucose + 100 g fructose dissolved in 1000 ml tap water) over a continuous moderate exercise of 90 minutes. CSII = continuous subcutaneous insulin infusion. MDI=multiple daily injections.

    Procedure: GLU first, GLU-FRU second

  • Experimental
    GLU-FRU first, GLU second, CSII therapy

    GLU-FRU : ingestion of a 20% carbohydrate solution (consisting of 100 g glucose + 100 g fructose dissolved in 1000 ml tap water) over a continuous moderate exercise of 90 minutes. GLU (occurring after a washout period of 2-8 weeks): ingestion of a 10% carbohydrate solution (consisting of 100 g glucose dissolved in 1000 ml tap water) over a continuous moderate exercise of 90 minutes. CSII = continuous subcutaneous insulin infusion. MDI=multiple daily injections.

    Procedure: GLU-FRU first, GLU second

Interventions

  • ProcedureIHE first, CONT second

    IHE: intermittent high intensity exercise: integration of 10 s maximal sprints every 10 minutes in a continuous low to moderate intensity exercise of 90 minutes. CONT (occurring after a washout period of 2-8 weeks): continuous moderate intensity exercise of 90 minutes

  • ProcedureCONT first, IHE second

    CONT: continuous moderate intensity exercise of 90 minutes. IHE (occurring after a washout period of 2-8 weeks): intermittent high intensity exercise: integration of 10 s maximal sprints every 10 minutes in a continuous low to moderate intensity exercise of 90 minutes

  • ProcedureGLU first, GLU-FRU second

    : ingestion of a 6% carbohydrate solution (consisting of 90 g glucose dissolved in 1500 ml tap water) over a continuous moderate exercise of 90 minutes. GLU FRU (occurring after a washout period of 2-8 weeks): ingestion of a 12% carbohydrate solution (consisting of 90 g glucose + 90 g fructose dissolved in 1500 ml tap water) over a continuous moderate exercise of 90 minutes

  • ProcedureGLU-FRU first, GLU second

    GLU-FRU : ingestion of a 12% carbohydrate solution (consisting of 90 g glucose + 90 g fructose dissolved in 1500 ml tap water) over a continuous moderate exercise of 90 minutes. GLU (occurring after a washout period of 2-8 weeks): : ingestion of a 6% carbohydrate solution (consisting of 90 g glucose dissolved in 1500 ml tap water) over a continuous moderate exercise of 90 minutes.

06

What researchers measure

Primary outcomes

  1. Amount of exogenous glucose required to maintain glycemia within a range between 7-10mM

    Time frame: 30 minutes (last 30 minutes of 90 min exercise period)

Secondary outcomes

  1. Exercise - related glycogen consumption

    Time frame: 90 minutes

  2. Glucose kinetics

    Rate of glucose appearance and disappearance

    Time frame: 180 minutes

  3. Counterregulatory hormones, metabolites, and inflammatory response

    Time frame: 300 minutes

  4. Spiroergometric parameters

    CO2 and O2 production, RER

    Time frame: 180 minutes

  5. Pre- and post-exercise glycemic excursions

    Time frame: 72 h pre-exercise and 72 h post-exercise respectively

  6. Heart rate variability

    Time frame: 90 minutes

07

Study locations

1 site
  • Division of Endocrinology, Diabetes and Clinical Nutrition, Bern University Hospital
    Bern, 3010, Switzerland
08

References and documents

Publications

  • Stettler C, Jenni S, Allemann S, Steiner R, Hoppeler H, Trepp R, Christ ER, Zwahlen M, Diem P. Exercise capacity in subjects with type 1 diabetes mellitus in eu- and hyperglycaemia. Diabetes Metab Res Rev. 2006 Jul-Aug;22(4):300-6. doi: 10.1002/dmrr.608. PubMed 16302286 ↗
  • Jenni S, Oetliker C, Allemann S, Ith M, Tappy L, Wuerth S, Egger A, Boesch C, Schneiter P, Diem P, Christ E, Stettler C. Fuel metabolism during exercise in euglycaemia and hyperglycaemia in patients with type 1 diabetes mellitus--a prospective single-blinded randomised crossover trial. Diabetologia. 2008 Aug;51(8):1457-65. doi: 10.1007/s00125-008-1045-5. Epub 2008 May 30. PubMed 18512043 ↗
  • Bussau VA, Ferreira LD, Jones TW, Fournier PA. The 10-s maximal sprint: a novel approach to counter an exercise-mediated fall in glycemia in individuals with type 1 diabetes. Diabetes Care. 2006 Mar;29(3):601-6. doi: 10.2337/diacare.29.03.06.dc05-1764. PubMed 16505513 ↗
  • Bussau VA, Ferreira LD, Jones TW, Fournier PA. A 10-s sprint performed prior to moderate-intensity exercise prevents early post-exercise fall in glycaemia in individuals with type 1 diabetes. Diabetologia. 2007 Sep;50(9):1815-1818. doi: 10.1007/s00125-007-0727-8. Epub 2007 Jun 22. PubMed 17583795 ↗
  • Guelfi KJ, Jones TW, Fournier PA. The decline in blood glucose levels is less with intermittent high-intensity compared with moderate exercise in individuals with type 1 diabetes. Diabetes Care. 2005 Jun;28(6):1289-94. doi: 10.2337/diacare.28.6.1289. PubMed 15920041 ↗
  • Guelfi KJ, Ratnam N, Smythe GA, Jones TW, Fournier PA. Effect of intermittent high-intensity compared with continuous moderate exercise on glucose production and utilization in individuals with type 1 diabetes. Am J Physiol Endocrinol Metab. 2007 Mar;292(3):E865-70. doi: 10.1152/ajpendo.00533.2006. PubMed 17339500 ↗
  • Iscoe KE, Riddell MC. Continuous moderate-intensity exercise with or without intermittent high-intensity work: effects on acute and late glycaemia in athletes with Type 1 diabetes mellitus. Diabet Med. 2011 Jul;28(7):824-32. doi: 10.1111/j.1464-5491.2011.03274.x. PubMed 21388440 ↗
  • Lecoultre V, Benoit R, Carrel G, Schutz Y, Millet GP, Tappy L, Schneiter P. Fructose and glucose co-ingestion during prolonged exercise increases lactate and glucose fluxes and oxidation compared with an equimolar intake of glucose. Am J Clin Nutr. 2010 Nov;92(5):1071-9. doi: 10.3945/ajcn.2010.29566. Epub 2010 Sep 8. PubMed 20826630 ↗
  • Eckstein ML, Farinha JB, McCarthy O, West DJ, Yardley JE, Bally L, Zueger T, Stettler C, Boff W, Reischak-Oliveira A, Riddell MC, Zaharieva DP, Pieber TR, Muller A, Birnbaumer P, Aziz F, Brugnara L, Haahr H, Zijlstra E, Heise T, Sourij H, Roden M, Hofmann P, Bracken RM, Pesta D, Moser O. Differences in Physiological Responses to Cardiopulmonary Exercise Testing in Adults With and Without Type 1 Diabetes: A Pooled Analysis. Diabetes Care. 2021 Jan;44(1):240-247. doi: 10.2337/dc20-1496. Epub 2020 Nov 12. PubMed 33184152 ↗
  • Bally L, Zueger T, Buehler T, Dokumaci AS, Speck C, Pasi N, Ciller C, Paganini D, Feller K, Loher H, Rosset R, Wilhelm M, Tappy L, Boesch C, Stettler C. Metabolic and hormonal response to intermittent high-intensity and continuous moderate intensity exercise in individuals with type 1 diabetes: a randomised crossover study. Diabetologia. 2016 Apr;59(4):776-84. doi: 10.1007/s00125-015-3854-7. Epub 2016 Jan 6. PubMed 26739816 ↗
  • Bally L, Zueger T, Pasi N, Carlos C, Paganini D, Stettler C. Accuracy of continuous glucose monitoring during differing exercise conditions. Diabetes Res Clin Pract. 2016 Feb;112:1-5. doi: 10.1016/j.diabres.2015.11.012. Epub 2015 Dec 19. PubMed 26739116 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 10, 2016, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02068638
Collaborators
University of Bern, University of Lausanne
Responsible party
Sponsor
First posted
Feb 21, 2014
Start date
Feb 2014
Primary completion
Jul 2016
Completion
Jul 2016
Last update
Aug 10, 2016

Study contacts

Christoph Stettler, Professor, MD
principal investigator · University of Bern

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Aug 2016. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion