Ignite Creation Date:
2024-05-06 @ 8:20 PM
Last Modification Date:
2024-10-26 @ 3:25 PM
Study NCT ID:
NCT06342024
Status:
RECRUITING
Last Update Posted:
2024-04-02
First Post:
2024-03-11
Brief Title:
Pistachio Consumption on Inflammatory Markers and Lean Body Mass
Sponsor:
Virginia Polytechnic Institute and State University
Organization:
Virginia Polytechnic Institute and State University
Study Overview
Official Title:
Effects of Pistachio Consumption on Inflammatory Markers and Lean Body Mass in Recreationally Active Women and Men
Status:
RECRUITING
Status Verified Date:
2024-03
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Pistachio nuts Pistacia vera L are a nutrient- and energy-dense food and are a significant source of 15 different micronutrients In addition to an excellent micronutrient profile pistachios are a good source of monounsaturated and polyunsaturated fats linoleic acid oleic acid and plant sterols Pistachios have the lowest amount of total fat and the highest protein fiber and phytosterol content compared to other nuts They possess a high antioxidant content Specifically pistachios have high amounts of lutein zeaxanthin and phenolic compounds eg anthocyanins flavonoids and proanthocyanidins These aforementioned compounds are known for their anti-inflammatory effects Pistachios also have been shown to reduce the risk of cardiovascular disease metabolic syndrome and all-cause mortality
The purpose of this study will be to determine the effects of consuming 15 ounces of pistachios per day compared to consuming no pistachios per day on inflammatory markers creatine kinase C-reactive protein cortisol Interleukin-8 tumor necrosis factor-alpha copper-zinc superoxide dismutase and glutathione peroxidase concentrations and lean body mass in women and men 40 to 60 years of age who have been recreationally active for at least six months exercising three to five days per week It is hypothesized that pistachio consumption will significantly lower inflammatory response and significantly increase lean body mass
This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios Those consuming pistachios will be in addition to their usual diet
The overall goal of this study is to evaluate the effects of pistachio consumption on inflammatory markers and lean body mass in women and men 40 to 60 years of age who exercise three to five days per week This study could provide a simple healthy way for recreationally active individuals to decrease inflammation and improve body composition
The purpose of this study will be to determine the effects of consuming 15 ounces of pistachios per day compared to consuming no pistachios per day on inflammatory markers creatine kinase C-reactive protein cortisol Interleukin-8 tumor necrosis factor-alpha copper-zinc superoxide dismutase and glutathione peroxidase concentrations and lean body mass in women and men 40 to 60 years of age who have been recreationally active for at least six months exercising three to five days per week It is hypothesized that pistachio consumption will significantly lower inflammatory response and significantly increase lean body mass
This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios Those consuming pistachios will be in addition to their usual diet
The overall goal of this study is to evaluate the effects of pistachio consumption on inflammatory markers and lean body mass in women and men 40 to 60 years of age who exercise three to five days per week This study could provide a simple healthy way for recreationally active individuals to decrease inflammation and improve body composition
Detailed Description:
The overall goal of the study is to evaluate the effects of pistachio consumption on inflammatory markers and lean body mass in women and men 40 to 60 years of age who exercise three to five days per week To determine the effects of consuming 15 ounces of pistachios per day compared to a control group on inflammatory markers creatine kinase C-reactive protein cortisol Interleukin-8 tumor necrosis factor-alpha copper-zinc superoxide dismutase and glutathione peroxidase concentrations and lean body mass in women and men 40 to 60 years of age who have been recreationally active for at least six months exercising three to five days per week
This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day versus a control consuming no pistachios The pistachios will be in addition to their usual diet
Dietary Intervention including Dietary Evaluation The dietary intervention will be to randomly assign 144 participants to consume 15 ounces of pistachios per day 72 participants or a control group consuming no pistachios 72 participants That will be the only change will be implemented into the participants diets Because a number of researchers have shown that adding pistachios to the diet does not lead to weight gain participants will not be asked to alter their diets in any way except to add consumption of 15 ounces of pistachios per day for six months or have no change in their diet control group depending on the group to which they were randomly assigned
Two-week Baseline Run-in Period A two-week baseline run-in period will be incorporated during which participants will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios The pistachios will be in addition to their usual diet
Why incorporate a two-week baseline run-in period First a run-in period is used after recruitment but prior to randomizing participants With a run-in period even if there will be no treatment during the run-in period as in our study it allows the researchers to assess participant participation prior to randomization If a participant is not receptive to any contact eg emails phone calls during the run-in period it will allow the researchers to exclude them from participating which can increase the studys power However a run-in period might lead to negative effects It could influence external validity by excluding participants from the study A run-in period could also affect internal validity by inflating the intent-to-treat effect estimate In addition researchers should report why any participants were excluded during the run-in period and describe their baseline characteristics in any publications
Dietary Intake and Physical Activity Assessment A Block 2014 full length food frequency questionnaire FFQ physical activity screener for adults NutritionQuest Berkeley CA at baseline only Food frequency questionnaires provide an overall food and beverage intake over the past year The Block 2014 FFQ physical activity screener combines a full-length FFQ with a short physical activity screening tool The Block 2014 FFQ physical activity screener has 127 food and beverage items The database for analyses was created from the United States Department of Agricultures USDAs Food and Nutrient Database for Dietary Studies 50 the Food Pyramid Equivalents Database and the Nutrient Database for Standard Reference The Block 2014 FFQ physical activity screener provides portion size photos for food and beverage intake The short physical activity screener incorporates 11 common physical activities derived from evaluation of the National Human Activities Patterns Survey and assesses total minutes metabolic equivalent MET minutes and energy expenditure We chose to use the Block 2014 FFQ physical activity screener because it will also provide the researchers with an overall assessment of participants physical activity
Adherence Assessment Participants randomly assigned to the pistachio group will receive a three-month supply of pistachios 15-ounce packets after baseline data collection The participants will be provided with the pistachios in portion-controlled packets to ensure adherence and to decrease any barriers to consumption
Enough pistachios will be provided to the participants for three months so that participants must return to our laboratory to receive another three-month supply When participants return to our laboratory at three months they will be asked to bring any unused packets of pistachios with them At the three-month time point the researchers will document any unconsumed packets of pistachios Participants will be asked why they did not consume some of their pistachio packets and document their reasons The researchers will then provide participants with another three-month supply of pistachios which will take them to the end of the study If participants do not consume 80 or more of the pistachios provided they will be dropped from the study
Blood Collection and Analyses Primary Fasting serum C-reactive protein serum Interleukin-8 serum tumor necrosis factor-alpha plasma copper-zinc superoxide dismutase plasma glutathione peroxidase serum creatine kinase and serum cortisol concentrations will all be assessed at baseline three months and end of study Participants will arrive at the phlebotomy room in Wallace Hall at Virginia Tech in the morning after an overnight fast 10-hour fast For all blood collections venous blood will be collected in serum tubes no anti-coagulant or in plasma tubes with heparin or EDTA as an anti-coagulant by a trained phlebotomist Twenty 20 milliliters mL of blood will be collected from each participant at each time point Ten mL will be collected into serum tubes no anti-coagulant and 10 mL will be collected into plasma tubes with heparin or EDTA as an anti-coagulant The three-month data collection will not only allow the researchers to collect more data but it will also allow the researchers to have another check-in with all participants but in particular those in the control group In addition the researchers will try to schedule the blood draws at the same time that the participants in the pistachio group will come to the lab for their blood draw
Following the blood collection red blood cells will be separated from serum or plasma via centrifugation at 3000 rpm 1500xg for 15 minutes Serum blood samples will first need to clot on ice for one hour prior to centrifugation Plasma samples will be centrifuged immediately after each blood draw The clear supernatant will be aliquoted into properly labeled 15 mL Eppendorf tubes Eppendorf AG Massachusetts USA and Germany using disposable transfer pipettes The tubes for all determinations will be stored at -80C until required for analyses All blood samples will be analyzed in duplicate for all the aforementioned biomarkers
Enzyme-Linked Immunosorbent Assays ELISA ThermoFisher Scientific Waltham MA will be used to assess all biomarkers using a BioTek Synergy H1 Hybrid Multi-Mode Monochromator Fluorescence Microplate Reader Fisher Scientific Hanover Place IL All blood analyses will be conducted at the end of the study to minimize differences among ELISA kits All blood analyses will be performed in the Nutritional Biochemistry Laboratory in Wallace Hall Department of Human Nutrition Foods and Exercise Virginia Tech
The aforementioned biomarkers were selected for several reasons First they are some of the key inflammatory markers in the body In addition they provide a balance of inflammatory markers and antioxidants Finally not all of them have been measured in studies where pistachios were consumed as part of the intervention
Lean Body Mass Assessment Primary The researchers will use a Lunar iDXA2 MTY dual energy X-ray absorptiometer DXA GE Precision Healthcare LLC Chicago IL to analyze body composition specifically lean body mass The DXA is considered a gold standard for assessing lean body mass percent body fat and bone mineral density A total body scan takes about five minutes The amount of radiation exposure is no more than what one would obtain from a cross-country plane flight We will measure body composition at baseline and end of study The researchers will not measure body composition at three months for two because we do not want to add one more exposure of radiation to the participants
Body Weight Height Body Mass Index and Waist Circumference Secondary To obtain descriptive data body weight will be measured to the nearest 025 kg without shoes and with the same clothes on a calibrated balance-beam scale Seca Hamburg Germany Height will be measured to the nearest 05 cm using a stadiometer attached to the balance-beam scale The researchers will measure body weight and height twice and take the average of each of the measures The researchers have incorporated this method for a number of years to increase accuracy when assessing body weight and height Body mass index BMI will be computed using the following equation BMI weight kilogramsheight meters2 Participants will be asked to wear the same clothes for each data collection and for ease of other anthropometric measurements The researchers want body weight to remain stable throughout the study period
It has been established that waist circumference measurements are a simple reliable assessment of visceral fat within the abdomen Participants will be asked to stand with their feet about shoulder-width apart and with their weight equally distributed on each leg They will be asked to breathe normally with the reading taken at the end of gentle exhaling Waist circumference will be measured at one inch above the umbilicus in triplicate to the nearest 05 cm using a Gulick tape measure The average of the three measures will be used as the value We will measure body weight height BMI and waist circumference at baseline and end of study
Statistical Evaluations including Power Calculation Database Set-up and Management The Research Electronic Data Capture REDCap system will be used as a central resource for data processing and management As the front-end collection instrument is created REDCap automatically creates a back-end database designed to store the data that will be recorded from the research Virginia Techs VTs Office of Export and Secure Research Compliance OESRC has licensed its own version of REDCap that is hosted on-premise at the Andrews Information Systems Building REDCap was developed specifically around the Health Insurance Portability and Accountability Act HIPAA-Security guidelines to support online and offline data capture for research studies and operations It provides an intuitive interface for data entry with data validation audit trails for tracking data manipulation and export procedures and automated export procedures for seamless data downloads
Study Design This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios Those in the pistachio group will consume pistachios in addition to their usual diet
Randomization The researchers will randomize eligible participants to one of two groups pistachio vs control using permuted block randomization with stratification to balance assignment by sex Randomization allocation tables will be created by a biostatistician not involved in the clinical trial using SAS software version 94 SAS Institute Cary NC USA The tables will be stored within the REDCap system at Virginia Tech in such a way that only the biostatistician will be able to view them Study outcomes will be analyzed blind to allocation status
Sample Size and Power Calculation The primary outcome is change in inflammatory response measured by C-reactive protein concentrations from the baseline run-in period to six months Power for this study was based on results for C-reactive protein concentrations of healthy adults receiving a dietary intervention where the assumed mean C-reactive protein concentration at baseline is 153 mgL standard deviation SD 152 mgL For within-group comparisons a sample size of 60 healthy adults per group 120 total achieves 80 power to detect paired mean differences of 062 Cohens d 041 small-medium effect and is based on a two-sided paired t-test when specifying a significance level of α0025 For between-group comparisons sample sizes of 60 per group 120 total achieves 80 power to detect a mean difference of 086 Cohens d057 medium effect based on a two-sided two-sample t-test assuming equal variances and α0025 To account for a possible 20 attrition rate we will recruit 144 participants 72 participants per group
Data Analyses Preliminary Analyses Descriptive statistics including measures of central tendency mean median and variation standard deviation interquartile range range for continuous measures and frequencies and percentages for dichotomous and categorical measures will be used to characterize the sample Should deviations from normality emerge transformations will be applied or non-parametric tests will be implemented and compared to parametric tests Of note while the researchers expect the groups to be balanced on baseline characteristics due to randomization imbalances that occur by chance will be adjusted for in all analyses
Missing Data Methods While every effort will be made to obtain complete data on every participant some missing data is inevitable The underlying mechanism missing completely at random MCAR missing at random MAR or missing not at random MNAR will be evaluated prior to adjusting to minimize bias from missing data The assumption of MAR which supports the use of multiple imputation by chained equations will be evaluated by regressing an indicator of missingness on known covariates using multiple logistic regression The analytic methods proposed will take advantage of all available data Baseline characteristics will be compared among participants with and without complete data recognizing that statistical power associated with finding true statistical differences may be limited To assess potential biases a comparison of response rates will be included If missing data is minimal 5 and can be considered MAR or MCAR then the primary hypothesis will be tested using the complete observed data
Aim 1 Analyses The primary aim of this study is to examine the effects of consuming pistachios on inflammatory response measured by creatine kinase C-reactive protein cortisol Interleukin-8 tumor necrosis factor-alpha copper-zinc superoxide dismutase and glutathione peroxidase concentrations and lean body mass measured by DXA Changes from baseline three months and six months in each outcome in response to dietary intervention will rely on linear mixed effects models that include random effects for participants and fixed effects for diet and time baseline run-in three months six months Model assumptions will be assessed both quantitatively and visually using goodness-of-fit statistics and diagnostic plots Additional secondary analyses will include general linear modeling where difference scores six months timepoint minus baseline six months timepoint minus three months timepoint three months timepoint minus baseline will be regressed on dietary intervention groups
Potential ImpactRelevance to Scientific Discovery This study could provide a simple healthy way for recreationally active individuals to decrease inflammation and improve body composition The fact that pistachios are a whole food and not a supplement lends itself to a positive approach to health and wellness Researching the benefits pistachios could have in healthy active adults provides another avenue to encourage individuals to consume more of this healthy food
This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day versus a control consuming no pistachios The pistachios will be in addition to their usual diet
Dietary Intervention including Dietary Evaluation The dietary intervention will be to randomly assign 144 participants to consume 15 ounces of pistachios per day 72 participants or a control group consuming no pistachios 72 participants That will be the only change will be implemented into the participants diets Because a number of researchers have shown that adding pistachios to the diet does not lead to weight gain participants will not be asked to alter their diets in any way except to add consumption of 15 ounces of pistachios per day for six months or have no change in their diet control group depending on the group to which they were randomly assigned
Two-week Baseline Run-in Period A two-week baseline run-in period will be incorporated during which participants will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios The pistachios will be in addition to their usual diet
Why incorporate a two-week baseline run-in period First a run-in period is used after recruitment but prior to randomizing participants With a run-in period even if there will be no treatment during the run-in period as in our study it allows the researchers to assess participant participation prior to randomization If a participant is not receptive to any contact eg emails phone calls during the run-in period it will allow the researchers to exclude them from participating which can increase the studys power However a run-in period might lead to negative effects It could influence external validity by excluding participants from the study A run-in period could also affect internal validity by inflating the intent-to-treat effect estimate In addition researchers should report why any participants were excluded during the run-in period and describe their baseline characteristics in any publications
Dietary Intake and Physical Activity Assessment A Block 2014 full length food frequency questionnaire FFQ physical activity screener for adults NutritionQuest Berkeley CA at baseline only Food frequency questionnaires provide an overall food and beverage intake over the past year The Block 2014 FFQ physical activity screener combines a full-length FFQ with a short physical activity screening tool The Block 2014 FFQ physical activity screener has 127 food and beverage items The database for analyses was created from the United States Department of Agricultures USDAs Food and Nutrient Database for Dietary Studies 50 the Food Pyramid Equivalents Database and the Nutrient Database for Standard Reference The Block 2014 FFQ physical activity screener provides portion size photos for food and beverage intake The short physical activity screener incorporates 11 common physical activities derived from evaluation of the National Human Activities Patterns Survey and assesses total minutes metabolic equivalent MET minutes and energy expenditure We chose to use the Block 2014 FFQ physical activity screener because it will also provide the researchers with an overall assessment of participants physical activity
Adherence Assessment Participants randomly assigned to the pistachio group will receive a three-month supply of pistachios 15-ounce packets after baseline data collection The participants will be provided with the pistachios in portion-controlled packets to ensure adherence and to decrease any barriers to consumption
Enough pistachios will be provided to the participants for three months so that participants must return to our laboratory to receive another three-month supply When participants return to our laboratory at three months they will be asked to bring any unused packets of pistachios with them At the three-month time point the researchers will document any unconsumed packets of pistachios Participants will be asked why they did not consume some of their pistachio packets and document their reasons The researchers will then provide participants with another three-month supply of pistachios which will take them to the end of the study If participants do not consume 80 or more of the pistachios provided they will be dropped from the study
Blood Collection and Analyses Primary Fasting serum C-reactive protein serum Interleukin-8 serum tumor necrosis factor-alpha plasma copper-zinc superoxide dismutase plasma glutathione peroxidase serum creatine kinase and serum cortisol concentrations will all be assessed at baseline three months and end of study Participants will arrive at the phlebotomy room in Wallace Hall at Virginia Tech in the morning after an overnight fast 10-hour fast For all blood collections venous blood will be collected in serum tubes no anti-coagulant or in plasma tubes with heparin or EDTA as an anti-coagulant by a trained phlebotomist Twenty 20 milliliters mL of blood will be collected from each participant at each time point Ten mL will be collected into serum tubes no anti-coagulant and 10 mL will be collected into plasma tubes with heparin or EDTA as an anti-coagulant The three-month data collection will not only allow the researchers to collect more data but it will also allow the researchers to have another check-in with all participants but in particular those in the control group In addition the researchers will try to schedule the blood draws at the same time that the participants in the pistachio group will come to the lab for their blood draw
Following the blood collection red blood cells will be separated from serum or plasma via centrifugation at 3000 rpm 1500xg for 15 minutes Serum blood samples will first need to clot on ice for one hour prior to centrifugation Plasma samples will be centrifuged immediately after each blood draw The clear supernatant will be aliquoted into properly labeled 15 mL Eppendorf tubes Eppendorf AG Massachusetts USA and Germany using disposable transfer pipettes The tubes for all determinations will be stored at -80C until required for analyses All blood samples will be analyzed in duplicate for all the aforementioned biomarkers
Enzyme-Linked Immunosorbent Assays ELISA ThermoFisher Scientific Waltham MA will be used to assess all biomarkers using a BioTek Synergy H1 Hybrid Multi-Mode Monochromator Fluorescence Microplate Reader Fisher Scientific Hanover Place IL All blood analyses will be conducted at the end of the study to minimize differences among ELISA kits All blood analyses will be performed in the Nutritional Biochemistry Laboratory in Wallace Hall Department of Human Nutrition Foods and Exercise Virginia Tech
The aforementioned biomarkers were selected for several reasons First they are some of the key inflammatory markers in the body In addition they provide a balance of inflammatory markers and antioxidants Finally not all of them have been measured in studies where pistachios were consumed as part of the intervention
Lean Body Mass Assessment Primary The researchers will use a Lunar iDXA2 MTY dual energy X-ray absorptiometer DXA GE Precision Healthcare LLC Chicago IL to analyze body composition specifically lean body mass The DXA is considered a gold standard for assessing lean body mass percent body fat and bone mineral density A total body scan takes about five minutes The amount of radiation exposure is no more than what one would obtain from a cross-country plane flight We will measure body composition at baseline and end of study The researchers will not measure body composition at three months for two because we do not want to add one more exposure of radiation to the participants
Body Weight Height Body Mass Index and Waist Circumference Secondary To obtain descriptive data body weight will be measured to the nearest 025 kg without shoes and with the same clothes on a calibrated balance-beam scale Seca Hamburg Germany Height will be measured to the nearest 05 cm using a stadiometer attached to the balance-beam scale The researchers will measure body weight and height twice and take the average of each of the measures The researchers have incorporated this method for a number of years to increase accuracy when assessing body weight and height Body mass index BMI will be computed using the following equation BMI weight kilogramsheight meters2 Participants will be asked to wear the same clothes for each data collection and for ease of other anthropometric measurements The researchers want body weight to remain stable throughout the study period
It has been established that waist circumference measurements are a simple reliable assessment of visceral fat within the abdomen Participants will be asked to stand with their feet about shoulder-width apart and with their weight equally distributed on each leg They will be asked to breathe normally with the reading taken at the end of gentle exhaling Waist circumference will be measured at one inch above the umbilicus in triplicate to the nearest 05 cm using a Gulick tape measure The average of the three measures will be used as the value We will measure body weight height BMI and waist circumference at baseline and end of study
Statistical Evaluations including Power Calculation Database Set-up and Management The Research Electronic Data Capture REDCap system will be used as a central resource for data processing and management As the front-end collection instrument is created REDCap automatically creates a back-end database designed to store the data that will be recorded from the research Virginia Techs VTs Office of Export and Secure Research Compliance OESRC has licensed its own version of REDCap that is hosted on-premise at the Andrews Information Systems Building REDCap was developed specifically around the Health Insurance Portability and Accountability Act HIPAA-Security guidelines to support online and offline data capture for research studies and operations It provides an intuitive interface for data entry with data validation audit trails for tracking data manipulation and export procedures and automated export procedures for seamless data downloads
Study Design This will be a randomized study where participants will first complete a two-week baseline run-in period during which they will consume their typical diet Following this participants will be randomized to one of two groups for six months consuming 15 ounces of pistachios per day or a control group consuming no pistachios Those in the pistachio group will consume pistachios in addition to their usual diet
Randomization The researchers will randomize eligible participants to one of two groups pistachio vs control using permuted block randomization with stratification to balance assignment by sex Randomization allocation tables will be created by a biostatistician not involved in the clinical trial using SAS software version 94 SAS Institute Cary NC USA The tables will be stored within the REDCap system at Virginia Tech in such a way that only the biostatistician will be able to view them Study outcomes will be analyzed blind to allocation status
Sample Size and Power Calculation The primary outcome is change in inflammatory response measured by C-reactive protein concentrations from the baseline run-in period to six months Power for this study was based on results for C-reactive protein concentrations of healthy adults receiving a dietary intervention where the assumed mean C-reactive protein concentration at baseline is 153 mgL standard deviation SD 152 mgL For within-group comparisons a sample size of 60 healthy adults per group 120 total achieves 80 power to detect paired mean differences of 062 Cohens d 041 small-medium effect and is based on a two-sided paired t-test when specifying a significance level of α0025 For between-group comparisons sample sizes of 60 per group 120 total achieves 80 power to detect a mean difference of 086 Cohens d057 medium effect based on a two-sided two-sample t-test assuming equal variances and α0025 To account for a possible 20 attrition rate we will recruit 144 participants 72 participants per group
Data Analyses Preliminary Analyses Descriptive statistics including measures of central tendency mean median and variation standard deviation interquartile range range for continuous measures and frequencies and percentages for dichotomous and categorical measures will be used to characterize the sample Should deviations from normality emerge transformations will be applied or non-parametric tests will be implemented and compared to parametric tests Of note while the researchers expect the groups to be balanced on baseline characteristics due to randomization imbalances that occur by chance will be adjusted for in all analyses
Missing Data Methods While every effort will be made to obtain complete data on every participant some missing data is inevitable The underlying mechanism missing completely at random MCAR missing at random MAR or missing not at random MNAR will be evaluated prior to adjusting to minimize bias from missing data The assumption of MAR which supports the use of multiple imputation by chained equations will be evaluated by regressing an indicator of missingness on known covariates using multiple logistic regression The analytic methods proposed will take advantage of all available data Baseline characteristics will be compared among participants with and without complete data recognizing that statistical power associated with finding true statistical differences may be limited To assess potential biases a comparison of response rates will be included If missing data is minimal 5 and can be considered MAR or MCAR then the primary hypothesis will be tested using the complete observed data
Aim 1 Analyses The primary aim of this study is to examine the effects of consuming pistachios on inflammatory response measured by creatine kinase C-reactive protein cortisol Interleukin-8 tumor necrosis factor-alpha copper-zinc superoxide dismutase and glutathione peroxidase concentrations and lean body mass measured by DXA Changes from baseline three months and six months in each outcome in response to dietary intervention will rely on linear mixed effects models that include random effects for participants and fixed effects for diet and time baseline run-in three months six months Model assumptions will be assessed both quantitatively and visually using goodness-of-fit statistics and diagnostic plots Additional secondary analyses will include general linear modeling where difference scores six months timepoint minus baseline six months timepoint minus three months timepoint three months timepoint minus baseline will be regressed on dietary intervention groups
Potential ImpactRelevance to Scientific Discovery This study could provide a simple healthy way for recreationally active individuals to decrease inflammation and improve body composition The fact that pistachios are a whole food and not a supplement lends itself to a positive approach to health and wellness Researching the benefits pistachios could have in healthy active adults provides another avenue to encourage individuals to consume more of this healthy food
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None