Effects of Peppermint Oil in Mild-moderate Hypertension. A Pilot Feasibility Study.

Study Overview
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Brief Summary
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Cardiovascular and associated hypertensive diseases are the leading health burden and cause of mortality worldwide; therefore, the necessity for effective interventions is paramount. Dietary interventions to improve cardiovascular health are highly sought after as they possess less risk and financial burden than pharmacological drugs. Our previous randomized trial has shown that oral peppermint can improving systolic blood pressure and other cardiovascular/ blood lipids in healthy individuals. However, to date, no research has explored this using a placebo randomized intervention in patients with hypertension. Therefore, the primary purpose of the proposed investigation is to test the ability of oral peppermint oil supplementation to improve cardiometabolic parameters in participants with mild-moderate hypertension.

Official Title
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Effects of Peppermint Oil in Cardiometabolic Outcomes in Participants With Mild-moderate Hypertension. A Pilot Feasibility Trial.

Conditions
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Hypertension, Cardiometabolic Syndrome

Intervention / Treatment
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* Dietary Supplement: Peppermint oil
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Meet 3 of 5 criteria for Metabolic Syndrome based on National Cholesterol Education Program-Adult Treatment Panel III guidelines: Waist Circumference: >102cm (men), >88cm (women) Fasting Triglycerides: ≥1.69 mmol.L-1 Fasting High Density Lipoprotein: <1.03 mmol.L-1 (men), <1.29 mmol.L-1 (women) Blood Pressure: ≥130 mmHg SBP or ≥85 mmHg DBP Fasting Glucose: ≥6.1 mmol.L-1 Exclusion Criteria: Smoking current Current or previous gastrointestinal, cardiovascular, hepatic or renal disease Current diabetes or extreme hypertension (≥160/100 mmHg) Allergy to peppermint Current medication (such as steroids, NSAIDs, antibiotics, antihypertensive, hypoglycaemic, lipid-lowering drugs) Currently using any nutritional supplement. Heavy alcohol consumption (>14 units per week).

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Identical in taste and colour to the supplement juice, but with no peppermint content. | Other: Placebo<br>* Placebo<br>|
| Experimental: Peppermint oil<br>50 uL of peppermint oil, which will be diluted with 100 mL of water - taken twice per day. | Dietary Supplement: Peppermint oil<br>* Peppermint oil<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic blood pressure | Systolic blood pressure - measured using a digital blood pressure monitor | Baseline | 
| Systolic blood pressure | Systolic blood pressure - measured using a digital blood pressure monitor | 20 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diastolic blood pressure | Diastolic blood pressure - measured using a digital blood pressure monitor | Baseline | 
| Diastolic blood pressure | Diastolic blood pressure - measured using a digital blood pressure monitor | 20 days | 
| Percent bodyfat | Participants percentage composition of fat - measured using bio-electrical impedance | Baseline | 
| Percent bodyfat | Participants percentage composition of fat - measured using bio-electrical impedance | 20 days | 
| Waist circumference | Waist circumference - measured using anthropocentric tape | Baseline | 
| Waist circumference | Waist circumference - measured using anthropocentric tape | 20 days | 
| Waist to hip ratio | Ratio of waist to hip circumference - measured using anthropocentric tape | Baseline | 
| Waist to hip ratio | Ratio of waist to hip circumference - measured using anthropocentric tape | 20 days | 
| Resting metabolic rate | Estimated daily calorie usage (Kcal) at rest - obtained using a metabolic cart through indirect calorimetry. | Baseline | 
| Resting metabolic rate | Estimated daily calorie usage (Kcal) at rest - obtained using a metabolic cart through indirect calorimetry. | 20 days | 
| Resting utilization of carbohydrates | Percent contribution of carbohydrate to daily calories - at rest - obtained using a metabolic cart through indirect calorimetry. | Baseline | 
| Resting utilization of carbohydrates | Percent contribution of carbohydrate to daily calories - at rest - obtained using a metabolic cart through indirect calorimetry. | 20 days | 
| Resting utilization of fats | Percent contribution of fats to daily calories - at rest - obtained using a metabolic cart through indirect calorimetry. | Baseline | 
| Resting utilization of fats | Percent contribution of fats to daily calories - at rest - obtained using a metabolic cart through indirect calorimetry. | 20 days | 
| Blood glucose | Capillary blood glucose - mmol/L | Baseline | 
| Blood glucose | Capillary blood glucose - mmol/L | 20 days | 
| Blood triglycerides | Capillary blood triglycerides - mmol/L | Baseline | 
| Blood triglycerides | Capillary blood triglycerides - mmol/L | 20 days | 
| Blood cholesterol (Total, HDL & LDL) | Capillary blood cholesterol - mmol/L | Baseline | 
| Blood cholesterol (Total, HDL & LDL) | Capillary blood cholesterol - mmol/L | 20 days | 
| Capillary blood haemoglobin | Capillary blood haemoglobin - g/L | Baseline | 
| Capillary blood haemoglobin | Capillary blood haemoglobin - g/L | 20 days | 
| Triglyceride glucose index | Log transformed measurement of the blood glucose and blood triglyceride measures outlined above. | Baseline | 
| Triglyceride glucose index | Log transformed measurement of the blood glucose and blood triglyceride measures outlined above. | 20 days | 
| Coop-Wonka chart | Psychological wellbeing - The Coop-Wonka chart is a six item questionnaire with a 1-5 scoring system for each thus the chart has a maximum score of 30 which indicates the lowest possible psychological Wellbeing. | Baseline | 
| Coop-Wonka chart | Psychological wellbeing - The Coop-Wonka chart is a six item questionnaire with a 1-5 scoring system for each thus the chart has a maximum score of 30 which indicates the lowest possible psychological Wellbeing. | 20 days | 
| Beck Depression Inventory | Psychological wellbeing - the Beck Depression Inventory is a 21 questionnaire with questions that range in scoring from 0-3, thus the maximum score is 63 which is the highest depression score possible. | Baseline | 
| Beck Depression Inventory | Psychological wellbeing - the Beck Depression Inventory is a 21 questionnaire with questions that range in scoring from 0-3, thus the maximum score is 63 which is the highest depression score possible. | 20 days | 
| State Trait Anxiety Inventory | Psychological wellbeing - the state trait anxiety inventory is a 40 item questionnaire with each question having a 1-4 score system, thus the maximum score is 80 which indicates the highest level of anxiety. | Baseline | 
| State Trait Anxiety Inventory | Psychological wellbeing - the state trait anxiety inventory is a 40 item questionnaire with each question having a 1-4 score system, thus the maximum score is 80 which indicates the highest level of anxiety. | 20 days | 
| Insomnia Severity Index | Sleep quality - The Insomnia Severity Index is a brief instrument designed to assess the severity of both nighttime and daytime components of insomnia. The Insomnia Severity Index is a 7-item self-report questionnaire yielding a total score ranging from 0 to 28. | Baseline | 
| Insomnia Severity Index | Sleep quality - The Insomnia Severity Index is a brief instrument designed to assess the severity of both nighttime and daytime components of insomnia. The Insomnia Severity Index is a 7-item self-report questionnaire yielding a total score ranging from 0 to 28. | 20 days | 
| Pittsburgh Sleep Quality Index | Sleep quality - The Pittsburgh Sleep Quality index, is a questionnaire that consists of 19 self-rated questions, grouped into 7 components. Each component is scored separately, weighted equally on a 0 - 3 scale and the scores of the 7 components are then added to give a global score, which has a range of 0 - 21 with higher scores indicating worse sleep quality. | Baseline | 
| Pittsburgh Sleep Quality Index | Sleep quality - The Pittsburgh Sleep Quality index, is a questionnaire that consists of 19 self-rated questions, grouped into 7 components. Each component is scored separately, weighted equally on a 0 - 3 scale and the scores of the 7 components are then added to give a global score, which has a range of 0 - 21 with higher scores indicating worse sleep quality. | 20 days | 
| Epworth Sleepiness Scale | Sleep quality - The Epworth Sleepiness Scale is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3) with a maximum score of 24. | Baseline | 
| Epworth Sleepiness Scale | Sleep quality - The Epworth Sleepiness Scale is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3) with a maximum score of 24. | 20 days |