Oxidative Stress, Carbohydrate Metabolism Disorders and G6PD Deficiency

Study Overview
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Brief Summary
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The purpose of this study is to investigate the effects of alpha-lipoic acid supplementation on redox status, physiological and biochemical parameters in diabetic individuals with G6PD deficiency, after acute exercise.

Detailed Description
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In a randomized double-blind, crossover design, a total of forty people will participate in the research voluntarily: (a) ten people with G6PD (Mediterranean type) enzyme deficiency), (b) ten people with G6PD (Mediterranean type) enzyme deficiency and a disorder of carbohydrate metabolism (diabetes, prediabetes), (c) ten people with a disorder of carbohydrate metabolism (diabetes mellitus and prediabetes) and, (d) ten people without any health problem (control group). They will be supplemented with either 600 mg of alpha-lipoic acid (experimental condition) or placebo (control condition) every day for 4 weeks, separated by a 4-week washout period. All participants will be randomly assigned to both conditions. Before intervention, all participants will be informed about the study protocol, fill a medical history questionnaire and sign an informed consent form. Moreover, measurements of anthropometric characteristics and physiological parameters, as well as a VO2peak test will be performed. Participants will perform a trial of exercise (70% VO2peak for 45min and 90% till exhaustion) before and after each condition (i.e. a total of 4 trials). Blood samples will be collected before, immediately after and 1 hour after each exercise trial. Moreover, measurements of anthropometric characteristics, physiological and psychological parameters will be performed before and after each condition.

Official Title
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The Association Between Oxidative Stress and Carbohydrate Metabolism Disorders in G6PD Deficient Individuals

Conditions
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G6PD Deficiency, Carbohydrate Metabolism Disorder, Oxidative Stress

Intervention / Treatment
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* Dietary Supplement: Alpha-lipoic acid
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals with normal G6PD activity Individuals with G6PD deficiency Individuals with CHO metabolism disorders (diabetes, prediabetes) Individuals with G6PD deficiency and CHO metabolism disorders (diabetes, prediabetes) Exclusion Criteria: Health problems that contraindicate participation to exercise Should not take any medication that affects the body's antioxidant mechanisms as well as dietary supplements containing antioxidants Women during lactation or gestation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: G6PD deficiency (only) - Intervention<br>Alpha-lipoic acid supplementation (600 mg/day) for 4 weeks in a counterbalanced manner to 10 G6PD deficient individuals. | Dietary Supplement: Alpha-lipoic acid<br>* A trial of acute exercise before and after 4 weeks of alpha-lipoic acid supplementation.<br>* Other names: Physical exercise;|
| Placebo Comparator: G6PD deficiency (only) - Placebo<br>Placebo administration for 4 weeks in a counterbalanced manner to 120 G6PD deficient individuals. | Other: Placebo<br>* A trial of acute exercise before and after 4 weeks of placebo supplementation.<br>* Other names: Physical exercise;|
| Experimental: G6PD deficiency and CHO metabolism disorder - Intervention<br>Alpha-lipoic acid supplementation (600 mg/day) for 4 weeks in a counterbalanced manner to 10 individuals with G6PD deficiency and a CHO metabolism disorder. | Dietary Supplement: Alpha-lipoic acid<br>* A trial of acute exercise before and after 4 weeks of alpha-lipoic acid supplementation.<br>* Other names: Physical exercise;|
| Placebo Comparator: G6PD deficiency and CHO metabolism disorder - Placebo<br>Placebo for 4 weeks in a counterbalanced manner to 10 individuals with G6PD deficiency and a CHO metabolism disorder. | Other: Placebo<br>* A trial of acute exercise before and after 4 weeks of placebo supplementation.<br>* Other names: Physical exercise;|
| Experimental: CHO metabolism disorder (only) - Intervention<br>Alpha-lipoic acid supplementation (600 mg/day) for 4 weeks in a counterbalanced manner to 10 individuals with a CHO metabolism disorder. | Dietary Supplement: Alpha-lipoic acid<br>* A trial of acute exercise before and after 4 weeks of alpha-lipoic acid supplementation.<br>* Other names: Physical exercise;|
| Placebo Comparator: CHO metabolism disorder (only) - Placebo<br>Placebo for 4 weeks in a counterbalanced manner to 10 individuals with a CHO metabolism disorder. | Other: Placebo<br>* A trial of acute exercise before and after 4 weeks of placebo supplementation.<br>* Other names: Physical exercise;|
| Experimental: Controls - Intervention<br>Alpha-lipoic acid supplementation (600 mg/day) for 4 weeks in a counterbalanced manner to 10 individuals without G6PD deficiency and/or any CHO metabolism disorder. | Dietary Supplement: Alpha-lipoic acid<br>* A trial of acute exercise before and after 4 weeks of alpha-lipoic acid supplementation.<br>* Other names: Physical exercise;|
| Placebo Comparator: Controls - Placebo<br>Placebo for 4 weeks in a counterbalanced manner to 10 individuals without G6PD deficiency and/or any CHO metabolism disorder. | Other: Placebo<br>* A trial of acute exercise before and after 4 weeks of placebo supplementation.<br>* Other names: Physical exercise;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in total antioxidant capacity following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Spectrophotometric assay for the determination of total antioxidant capacity using DPPH method. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in glutathione following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Spectrophotometric assay for the determination of total antioxidant capacity using DTNB method. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in uric acid following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Spectrophotometric assay for the determination of total antioxidant capacity using a clinical chemistry analyzer with commercially available kits. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in bilirubin following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Spectrophotometric assay for the determination of bilirubin using a clinical chemistry analyzer with commercially available kits. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in lipid peroxidation following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Determination of lipid peroxidation using malondialdehyde production assessment. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in protein carbonyls following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Index of blood redox status. Spectrophotometric assay for the determination of total antioxidant capacity using DNPH method. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in blood lipids following 4 weeks of supplementation and placebo at rest and following a trial of acute exercise. | Blood lipids (total cholesterol, LDL-c, HDH-c, triglycerides). Spectrophotometric assays for the determination of blood lipids using a clinical chemistry analyzer with commercially available kits. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in insulin resistance following 4 weeks of supplementation and placebo. | Measurement of blood glucose and insulin levels to assess HOMA-IR and evaluate insulin resistance. Spectrophotometric assay for the determination of blood glucose using a clinical chemistry analyzer with commercially available kits.Determination of blood insulin using commercially available Eliza kits. | Before and following 4 weeks of supplementation and placebo. | 
| Changes in glycated hemoglobin (HbA1c) following 4 weeks of supplementation and placebo. | Measurement of HbA1c using commercially available kits. | Before and following 4 weeks of supplementation and placebo. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in body composition following 4 weeks of intervention and placebo. | Body fat mass (in kg) and percentage, lean mass (in kg) and percentage | Before and following 4 weeks of supplementation and placebo. | 
| Changes in body mass index following 4 weeks of intervention and placebo. | Body mass (in kg) and height (in cm) | Before and following 4 weeks of supplementation and placebo. | 
| Changes in resting heart rate following 4 weeks of intervention and placebo. | Resting heart rate (beats per minute) measurement after at least 5 minutes at rest | Before and following 4 weeks of supplementation and placebo. | 
| Changes in blood pressure following 4 weeks of intervention and placebo. | Measurement of (systolic and diastolic) blood pressure (in mm Hg) after at least 5 minutes at rest | Before and following 4 weeks of supplementation and placebo. | 
| Changes in waist-to-hip ratio following 4 weeks of intervention and placebo. | Measurement of waist and hip circumference to calculate waist-to-hip ratio | Before and following 4 weeks of supplementation and placebo. | 
| Changes in complete blood count following 4 weeks of intervention and placebo. | Complete blood count | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Changes in psychometric test following 4 weeks of intervention and placebo. | Hospital Anxiety Depression Scale-HADS (Greek version) | Before and following 4 weeks of supplementation and placebo. | 
| Trial of VO2peak estimation. | VO2peak (mL/kg body weight/min) estimation with a treadmill protocol. | Before intervention. | 
| Nicotinamide-adenine dinucleotide phosphate (NADPH) | Spectrophotometric assay for the determination of NADPH in erythrocytes. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Glutathione Reductase (GR) | Spectrophotometric assay for the determination of GR in erythrocytes. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Glutathione peroxidase (GPx) | Spectrophotometric assay for the determination of GPx in erythrocytes. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Superoxide dismutases (SOD) | Spectrophotometric assay for the determination of SOD in erythrocytes. | Before, immediately after and 1 hour after each trial of exercise, in both conditions (supplement and placebo) | 
| Glucose Tolerance Test (GTT) | GTT for the investigation of changes in glucose control. | Before intervention (blood samples at 0, 30, 60, 90 and 120 minutes after intake of 75 g glucose). | 
| G6PD enzyme activity in erythrocytes | Quantification of G6PD activity in erythrocytes (units/gram of hemoglobin) of all participants using a commercially available kit. | Before intervention. During GTT (blood samples at 0, 30, 60, 90 and 120 minutes after intake of 75 g glucose). Also before, immediately after and 1, 2, 24 hours after each trial of exercise, in both conditions (supplement and placebo). |