Pistachios Blood Sugar Control, Heart and Gut Health

Study Overview
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Brief Summary
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A two-period randomized crossover study will be conducted to evaluate the effect of nighttime pistachio consumption (i.e., after dinner and before sleep) on fasting blood sugar levels, longer-term blood sugar control, and risk factors for heart disease. This study will also investigate how pistachios affects gut health.

Detailed Description
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A two-period randomized crossover trial will be conducted. Participants will be randomized to receive each treatment for 12 weeks followed by a minimum 4-week wash-out period. During the pistachio treatment, participants will consume two ounces per day (57 g) of pistachios as an evening snack. During the control phase subjects will be given advice to consume 1-2 exchanges of carbohydrate as an evening snack, which is consistent with usual care. Markers of glycemic control, cardiovascular risk factors and gut health will be assessed at the beginning and the end of each treatment period.

Official Title
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The Effect of Pistachios on Risk Factors for Cardiometabolic Disease in Individuals With Pre-diabetes: a Randomized, Cross-over Study

Conditions
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Type 2 Diabetes, Cardiovascular Diseases

Intervention / Treatment
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* Drug: Pistachio
* Other: Usual care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI ≥25 and ≤45 kg/m2 Fasting plasma glucose 100 - 125 mg/dL non-Smoking Exclusion Criteria: Diagnosed diabetes or fasting glucose >126 mg/dl Systolic blood pressure >160mmHg or diastolic blood pressure >100mmHg) Prescribed anti-hypertensive, lipid lowering or glucose lowering drugs Established cardiovascular disease, stroke, diabetes, liver, kidney or autoimmune disease or inflammatory conditions Use of supplements (psyllium, fish oil, soy lecithin, phytoestrogens) and botanicals and not willing to cease for the duration of the study Women who are pregnant, lactating, planning to become pregnant or have given birth in the past year Weight loss of >=10% of body weight within the 6 months prior to enrolling in the study Smoking or use of any tobacco products Allergy/intolerance/sensitive to pistachios Consumption of >14 alcoholic drinks/week Shift-workers and those who cannot consume a snack in the evening

Ages Eligible for Study
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Minimum Age: 30 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
Interventional Model Description: Crossover assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Evening Pistachio Consumption<br>Participants will consume two ounces per day (57 g) of pistachios as an evening snack (i.e., after dinner and before sleep). | Drug: Pistachio<br>* Unsalted pistachios<br>|
| Active Comparator: Usual care<br>Advice to consume a snack that contains 1-2 exchanges (15-30 g of carbohydrate) as an evening snack - this is consistent with the current standard of care for people with impaired fasting glucose. | Other: Usual care<br>* Advice and resources will be provided<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fasting plasma glucose concentration | Fasting blood glucose (mg/dL) | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HbA1c | HbA1c (%) will be assessed at the beginning and end of each treatment period | 12 weeks | 
| Serum insulin concentration (mIU/L) | fasting serum insulin levels assessed by blood draw | 12 weeks | 
| Peripheral systolic and diastolic blood pressure (mm Hg) | Blood pressure measured assessed using a SphymoCor Xcel (Atcor Medical). | 12 weeks | 
| Central systolic and diastolic blood pressure (mm Hg) | Blood pressure measured assessed using a SphymoCor Xcel (Atcor Medical). | 12 weeks | 
| Carotid-femoral pulse wave velocity (m/s) | A measure of arterial stiffness assessed using a SphymoCor Xcel (Atcor Medical). A higher percentage value is indicative of greater arterial stiffness. | 12 weeks | 
| Augmentation Index (%) | A measure of arterial stiffness assessed using a SphymoCor Xcel (Atcor Medical). A higher percentage value is indicative of greater arterial stiffness. | 12 weeks | 
| LDL cholesterol concentration (mg/dL) | Assessed using fasting blood draw | 12 weeks | 
| HDL cholesterol concentration | Assessed using fasting blood draw | 12 weeks | 
| Total cholesterol concentration | Assessed using fasting blood draw | 12 weeks | 
| Triglyceride concentration | Assessed using fasting blood draw | 12 weeks | 
| HOMA-IR | Assessed using fasting blood draw and standardized HOMA-IR calculation. Fasting plasma glucose multiplied by fasting plasma insulin divided by 405. | 12 weeks | 
| waist circumference (cm) | Measured 10 cm above the navel | 12 weeks | 
| body weight (lbs) | Assessed using calibrated scale in Clinical Research Center | 12 weeks | 
| Diet quality: Healthy Eating Index 2015 | Assessed using the Healthy Eating Index 2015 | 12 weeks | 
| Change in the composition of the gut microbiome | microbiome composition assessed using fecal collection kit | 12 weeks |