The purpose of this study is to look at the effect of consuming peanut butter at breakfast on blood sugar control, cognitive function, and heart disease risk factors in middle-aged adults with prediabetes.
This is a 2-period, randomized, crossover study. In random sequence order participants will undergo each of the following conditions for 12 weeks with a ≥ 8-week washout between the two periods: 1) provision of 43 g/day (1.5 oz/day) of peanut butter with instructions to consume it as part of breakfast (or the first meal of the day); 2) instructions to continue usual intake with matched study contact and resource provision. Testing will be conducted at the beginning and end of each period.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
56
Intake of 43 g/day of peanut butter as part of breakfast (or the first meal of the day)
Continue intake of usual diet.
The Pennsylvania State University
University Park, Pennsylvania, United States
Change in HbA1c
HbA1c will be assessed at the beginning and end of each 12-week period and expressed as percentage. The change in HbA1c will be calculated as the post-condition value minus the pre-condition value and expressed as percentage point change.
Time frame: 12 weeks
Change in fasting glucose
Change in fasting plasma glucose expressed as mg/dL. Change in glucose will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in fasting insulin
Change in fasting serum insulin expressed as micro IU/mL. Change in insulin will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Mean glucose
Mean glucose assessed by a continuous glucose monitor (CGM) expressed as mg/dL. The between-condition difference in mean glucose will be evaluated by comparing the mean glucose calculated from 7 days of CGM wear at the end of each study period.
Time frame: 12 weeks
Mean glucose time in range
Mean glucose time in range (70-140 mg/dL) assessed by a continuous glucose monitor (CGM) expressed as minutes per day. The between-condition difference in mean glucose time in range will be evaluated by comparing the mean glucose time in range from 7 days of CGM wear at the end of each study period.
Time frame: 12 weeks
Glycemic variability
Glycemic variability assessed by a continuous glucose monitor (CGM) expressed as the coefficient of variability. The between-condition difference in glycemic variability will be evaluated by comparing the glycemic variability calculated from 7 days of CGM wear at the end of each study period.
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Time frame: 12 weeks
Change in homeostatic model of insulin resistance (HOMA-IR)
HOMA-IR will be calculated as (fasting insulin μIU/mL × fasting glucose mg/dL) / 405. Change in HOMA-IR will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Difference in ambulatory processing speed
Ambulatory processing speed assessed by ecological momentary assessment (EMA) administered Symbol Search, expressed as median response time correct. The between-condition difference in ambulatory processing speed will be evaluated by comparing mean values from 7 days of EMA at the end of each study period.
Time frame: 12 weeks
Difference in ambulatory working memory
Ambulatory working memory assessed by ecological momentary assessment (EMA) administered Grid Memory, expressed as number of correct dots. The between-condition difference in ambulatory working memory will be evaluated by comparing mean values from 7 days of EMA at the end of each study period.
Time frame: 12 weeks
Difference in ambulatory attention
Ambulatory attention assessed by ecological momentary assessment (EMA) administered Multiple Object Tracking expressed as number of correct dots. The between-condition difference in ambulatory attention will be evaluated by comparing mean values from 7 days of EMA at the end of each study period.
Time frame: 12 weeks
Change in body weight
Change in body weight expressed as kg. Change in body weight will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Difference in hunger
Hunger assessed by ecological momentary assessment (EMA) administered visual analog scale (scored 0-100). The between-condition difference in hunger will be evaluated by comparing mean values from 7 days of EMA at the end of each study period.
Time frame: 12 weeks
Difference in satiety
Satiety assessed by ecological momentary assessment (EMA) administered visual analog scale (scored 0-100). The between-condition difference in satiety will be evaluated by comparing mean values from 7 days of EMA at the end of each study period.
Time frame: 12 weeks
Change in total cholesterol
Change in fasting serum total cholesterol expressed as mg/dL. Change in total cholesterol will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in LDL-cholesterol
Change in fasting serum LDL-cholesterol calculated with the Martin-Hopkins equation expressed as mg/dL. Change in LDL-cholesterol will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in triglycerides
Change in fasting serum triglycerides expressed as mg/dL. Change in triglycerides will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in HDL-cholesterol
Change in fasting serum HDL-cholesterol expressed as mg/dL. Change in HDL-cholesterol will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in non-HDL cholesterol
Change in fasting serum non-HDL cholesterol expressed as mg/dL. Change in non-HDL cholesterol will be calculated as the mean of the post-condition day 1 and day 2 testing values minus the mean of the pre-condition day 1 and day 2 testing values.
Time frame: 12 weeks
Change in central systolic and diastolic blood pressure
Change in central blood pressure measured using a SphymoCor Xcel (Atcor Medical) expressed as mmHg. Change in systolic and diastolic blood pressure will be calculated as the post-condition value minus the pre-condition value and expressed as mmHg.
Time frame: 12 weeks
Change in peripheral systolic and diastolic blood pressure
Change in peripheral blood pressure measured using a SphymoCor Xcel (Atcor Medical) expressed as mmHg. Change in systolic and diastolic blood pressure will be calculated as the post-condition value minus the pre-condition value and expressed as mmHg.
Time frame: 12 weeks
Change in carotid-femoral pulse wave velocity
Change in carotid-femoral pulse wave velocity (PWV) measured using a SphymoCor Xcel (Atcor Medical) expressed as m/s. Change in PWV will be calculated as the post-condition value minus the pre-condition value and expressed as m/s.
Time frame: 12 weeks
Change in diet quality
Assessed from a 24-hour recall completed prior to the beginning of each study period and at the end of each study period. Diet quality will be calculated according to the Healthy Eating Index-2020 (HEI). Change in HEI will be calculated at the post-condition value minus the pre-condition value
Time frame: 12 weeks