Alkaline Diet for Insulin Sensitivity

Study Overview
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Brief Summary
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The purpose of this study is to test the effect of increasing the body pH acutely with an alkaline medication (sodium bicarbonate, NaHCO3, sodibic) on glucose metabolism post meal in non diabetic subjects with normal renal function. The investigators aim to determine whether there is an acute reduction in venous blood pH following a typical Western-style (high acid load) breakfast in healthy men and women, and whether this effect is attenuated by the concurrent administration of an alkaline medication. The effect on glucose metabolism, hunger/satiety and arterial stiffness post meal will be assessed.

Detailed Description
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The aim of the study is to test the effect of increasing the body pH acutely with an alkali (NaHCO3) prior to a high acid load meal on glucose metabolism in non-diabetic men and women. This is a double-blind placebo-controlled randomised study with a crossover design. Study Procedures: Two (2) meal studies will be performed 1 to 2 weeks apart. Studies will include collecting fasting blood to assess circulating glucose, insulin, C-peptide, free fatty acids, glucagon-like peptide-1, acid/base markers, including electrolytes (EUC) and venous blood pH. Participants will then be either administered sodibic (1680 mg) or matching placebo and a standardised Western style/high acid load meal. Investigators and participants will be blinded to the intervention. Blood will be drawn every 15 min in the first hour and then every 30 min for 3 hours in total. Arterial stiffness and appetite score will be evaluated at ½ h intervals. Sample size: 30 sample size calculation: To detect a difference in area under the curve (AUC) of venous blood pH with a paired crossover design, 32 individuals will be required with statistical power 1-β>0.8 (allowing for drop-out). statistical considerations: Differences between AUC of outcome measures post sodium bicarbonate vs. placebo will be tested using paired t-tests. Two-way repeated measure ANOVA tests will be conducted to assess differences in the response to the meal with sodium bicarbonate vs. placebo.

Official Title
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Alkaline Diet for Insulin Sensitivity

Conditions
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Dysglycemia, Type 2 Diabetes Mellitus

Intervention / Treatment
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* Drug: Sodium Bicarbonate Oral Capsule
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age range: 22-65 Disease status: Healthy. Laboratory parameters: Fasting plasma glucose <7 mmol/L, HbA1c <6.5% (48 mmol/mol). Willingness to give written informed consent and willingness to participate and comply with the study. Exclusion Criteria: Individuals with a personal history of diabetes, hypertension, cardiovascular disease, kidney disease, respiratory disease or inflammatory disease. Individuals treated with medications known to affect insulin sensitivity. Individuals with fasting plasma glucose ≥7 mmol/L, HbA1c ≥6.5% (48 mmol/mol). Individuals with an unstable body weight in the past 3 months (+/- 2 kg or more). Individuals with a history of a psychological illness or condition that may interfere with the participant's ability to understand the requirements of the study. Individuals who smoke. Individuals who consume more than 40 g of alcohol daily.

Ages Eligible for Study
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Minimum Age: 22 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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sodium bicarbonate<br>High acid load meal (Western style meal) with Sodium bicarbonate (Sodibic 840mg*2) | Drug: Sodium Bicarbonate Oral Capsule<br>* Sodium bicarbonate 1680 mg will be administered prior to the meal<br>* Other names: Sodibic capsules (Aspen Australia, NSW, Australia);|
| Placebo Comparator: Placebo<br>High acid load meal (Western style meal) with sodibic-matching placebo | Drug: Placebo<br>* Sodibic-matching placebo (Stenlake Compounding Chemist, NSW, Australia) will be administered prior to the meal on a different day 1 to 2 weeks apart<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in venous blood pH | The investigators aim is to determine whether venous blood pH decreases after a high acid load meal, and whether this effect is attenuated by administration of sodium bicarbonate prior to a mixed meal study | Baseline (fasting) and 3 hours post meal | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in glycemic response to the meal | Postprandial glucose excursion will be compared between sodium bicarbonate and placebo | Baseline (fasting) and 3 hours post meal | 
| Changes in insulin response to the meal | Postprandial insulin excursion will be compared between sodium bicarbonate and placebo | Baseline (fasting) and 3 hours post meal | 
| Changes in arterial stiffness | Postprandial arterial stiffness (measured by the augmentation index derived from Sphygmocore, Atcor Medical, Australia) will be compared between sodium bicarbonate and placebo | Baseline (fasting) and 3 hours post meal | 
| Changes in hunger and satiety scores | Postprandial hunger and satiety will be compared between sodium bicarbonate and placebo | Baseline (fasting) and 3 hours post meal | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Glucose metabolism, Potential renal acid load, Postprandial glycemia, Body acid-base homeostasis, Sodium bicarbonate