Clinical trial NCT05094505: Isolated and Combined Effect of a Low Carbohydrate Diet and Exercise in Hypoxia in Patients With Type 2 Diabetes
Official title: Isolated and Combined Effect of a Low Carbohydrate Diet and Chronic Exercise Exposure to Hypoxia on Glycaemic Control and Cardiovascular Risk Factors in Patients With Type 2 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Carbohydrate
Hypoxia
Exercise
Diabetes Mellitus, Type 2
Lead sponsor: Universidade do Porto
Sponsor class: OTHER
Collaborators: name: Fundação para a Ciência e a Tecnologia
name: University Institute of Maia
First posted: 2021-10-26
Enrollment: 42
Sex: ALL
Maximum age (years): 75
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to determine the effects of isolated chronic exercise in hypoxia and combined exercise in hypoxia with a low carbohydrate diet on hypoxia-induced transcription factor (HIF1-α); glycaemic control and cardiovascular risk factors in patients with type 2 diabetes.

Detailed description: At baseline, diet plans will be individualized and energy-content prescriptions will be constant throughout the study to maintain the isocaloric control between diets. The planned macronutrient compositions will be, 30% of energy from carbohydrates, 20% from protein and 50% from fat for low carbohydrate diet (LCD) and 30% of energy from fat, 20% from protein and 50% from carbohydrates for the low-fat diet (control diet), during the 8 weeks. Both diets emphasis on low-glycemic index foods and limited saturated fat to 10% of energy, and calculated with appropriate software.

Exercise in hypoxia (at 3000m altitude, 3 sessions/week) will occur during a 8-week period intervention and all testing sessions carried out in a hypoxic chamber at Exercise Medical Center, Porto - Portugal. This chamber allows control of O2 (11-20.97%), temperature (until 50ºC), humidity (until 80%) and altitude (until 8000m). Exercise in hypoxia sessions will consist in 60 min on an ergometer (Excalibur, Lode, Netherlands) of continuous moderate and high intensity interval training, these latter considered as an efficient strategy to improve cardiorespiratory and metabolic health in patients with type 2 diabetes. Loads will be quantified according to pre-intervention testing assessments and controlled throughout each training session. All exercise testing and training sessions will be carried out at the same time of day (± 2 hours) and visits will be separated by at least 48h of recovery.

Height will be measured with use of a stadiometer (SECA), waist circumference was measured by using a tape measure positioned 3 cm above the iliac crest. Body mass index (BMI), weight, fat mass (FM) and fat-free mass (FFM) were determined by using whole-body dual-energy X-ray absorptiometry (Lunar Prodigy; General Electric Corp.). Blood pressure will be measured by using an automated sphygmomanometer (Dinamap Pro; Medical Systems,Tampa, FL) and haematological adaptations will be measured by collecting a venous blood sample from a vein in the arm using a needle. A total of 3 blood samples (pre, 1h post first intervention testing and 48h post the last intervention testing) will be taken.

Eligibility criteria: Inclusion Criteria:

* Diagnosis of type 2 diabetes for at least one year
* Glycosylated haemoglobin less than 10%
* Pharmacological regimen stabilized for at least three months
* Main complications of diabetes tracked and controlled (diabetic retinopathy, diabetic nephropathy, diabetic foot and main factors of cardiovascular risk)
* Previous participation in supervised exercise programs in the last 3 months
* Smoking absence in the last 6 months.

Exclusion Criteria:

* Diagnosis of type 2 diabetes for less than a year
* Glycosylated haemoglobin above 10%
* Pharmacological regimen less than three months
* Main complications of diabetes (diabetic retinopathy, diabetic nephropathy, diabetic foot and main factors of cardiovascular risk)
* Sedentary participants
* Smoking participants

Primary outcomes:
measure: Changes from pre- to pos intervention on glycated haemoglobin
timeFrame: Baseline and week 8
Secondary outcomes:
measure: Changes from pre- to post intervention in insulin resistance index and β-cell capacity
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention in angiogenesis
timeFrame: Baseline and week 8
Other outcomes:
measure: Changes from pre- to pos intervention on cardiovascular risk factor
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention respiratory and pulmonary gas-exchange variables
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention on body composition
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention on body mass index (BMI)
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention on waist circumference
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention on blood pressure
timeFrame: Baseline and week 8
measure: Changes from pre- to pos intervention on lipid profile
timeFrame: Baseline and week 8
Locations:
city: Porto
country: Portugal
facility: University of Porto
city: Porto
country: Portugal
facility: University of Maia
Study officials:
References:
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