How a Mediterranean Diet With Potatoes Impacts Heart and Metabolic Health in Adults With Pre-Diabetes

Study Overview: Investigators will recruit 60 adults with pre-diabetes from different demographic backgrounds, between the ages of 45 and 80 years to participate in a 12-week randomized controlled trial (RCT) examining baked potato with the skin (BP) + nutrition education focused on adherence for a Mediterranean Dietary Pattern (MEDNE) compared to MEDNE alone. Potential participants will be recruited from the metropolitan Las Vegas area through campus and community advertisements including flyers, newspaper articles, social media, and public events. Investigators will randomize eligible, consenting participants to receive either the BP+MEDNE or MEDNE in a 1:1 ratio. Investigators will use a computer-generated randomization method to manage the random assignment of either group.

Prescreen Interview: Potential participants who inquire about the study by calling the recruitment phone line, will be given a brief overview of the study and will be pre-screened by telephone interview to determine whether they should be invited for the in-person screening visit. Eligibility will be based on inclusion/exclusion criteria and responses to questions about medical history and dietary habits. Potential participants will be invited to report to the clinical facilities in the Health Sciences Building at UNLV (study site) for their first on-site visit (and all subsequent visits if the participant qualifies) to ascertain eligibility (screening study visit). This pre-screening interview will occur prior to participants consenting (which occurs at the in person screening study visit).

Screening Study Visit: Potential participants who inquire about the study by calling the recruitment phone line will be given a brief overview of the study and pre-screened by telephone to determine whether they should be invited for the in-person screening visit. Eligibility will be based on inclusion/exclusion criteria and responses to questions about medical and diet history during the pre-screen phone interview. Potentially eligible participants will be invited to report to the study site for their first on-site visit for screening (and all subsequent visits if the participant qualifies) to ascertain eligibility (Screening Study Visit). During the first in-person study visit for screening, the potential participants will be provided with verbal and written explanations of the project and will have any questions regarding the study answered by trained research personnel during the informed consent process. Consenting participants will be asked to sign an informed consent document (with a copy provided to the participant to take home). To confirm eligibility, the Screening Study Visit will consist of measurements of HbA1c (Afinion HbA1c Point of Care) via finger stick blood draw to confirm pre-diabetes, in addition to anthropometrics, blood pressure, and questions regarding medical history and medication use (fasting blood glucose via Libre Flash Glucose Monitoring Glucometer will be assessed but not as an eligibility criteria). Potential participants will also complete a component of a 7-day food frequency questionnaire, to indicate whether individuals frequently consume baked white potatoes. If participants are considered "non-frequent" white potato consumers, they will be included in the study and asked to come for subsequent visits and study visits. Participants who are not eligible will be thanked for their time and participation and told the specific reasoning for why they do not meet the inclusion criteria. Eligible participants will be asked to complete a three-day food record using NCI's Automated Self-Administered 24-Hour Dietary Assessment Tool to assess typical dietary intake and dietary quality (Healthy Eating Index [HEI]-2020 scoring), prior to their Baseline Study Visit at participants homes via a computer, ipad, or smartphone. The Automated Self-Administered 24-hour Dietary Assessment Tool (ASA24) is a web-based dietary recall system developed by the National Cancer Institute. It allows participants to self-report their dietary intake over the past 24 hours using a user-friendly interface that prompts for detailed food and beverage consumption. The tool can be distributed via a unique web link provided to participants, enabling remote data collection without requiring in-person visits.

Pre Baseline and 12-Week Visits: One week prior to the Baseline and 12-Week Study Visits, eligible participants will be asked to come to the study site to have placement of a continuous glucose monitor from training research staff (Dexcom G7) and wearable devices (ActiGraph Accelerometry) for assessments of real-time blood glucose levels, physical activity, and sleeping patterns. At their Baseline and 12-Week Study Visits, trained research staff will remove the Dexcom CGM from the participant and discard it. Similarly at their Baseline and 12-Week Study Visits, the Actigraph wearable device will be removed from trained research staff.

Baseline, 6- and 12-Week Study Visits: At the Baseline, 6-, and 12-Week Study Visits participants will be asked to come fasted to the study site (12 hours after the abstinence from caffeine and 24 hours after the last bout of moderate/heavy physical activity); vascular assessments (blood pressure, Pulse Wave Velocity, Pulse Wave Analysis) will be measured followed by body composition (Bioelectrical Impedance Analysis), finger prick blood draw (fasting blood glucose and HbA1c), venous blood draw (lipid profiles, inflammatory, and oxidative stress biomarkers), anthropometrics (height, weight, and waist/hip circumference), assessment of fruit and vegetable intake via Raman Spectroscopy, assessment of physical activity patterns (Five-City Project Physical Activity Recall), MD adherence (Mediterranean Diet Adherence Screener), and sleep quality (Pittsburg Sleep Quality Index). After assessments of outcome measurements at Baseline and 6-Week Study Visits (not at the 12-Week Study Visit), participants will be provided with BP+MEDNE or MEDNE (comparative control). All participants will be provided with MEDNE. In addition to all assessments mentioned for all study visits, at the 12-Week Study Visit there will be assessment of dietary and/or nutrition education acceptability and feasibility.

Dietary Assessments Throughout The Study Period (at week 1, 4, 8, and 12): Participants will be asked to complete a three-day food record using NCI's Automated Self-Administered 24-Hour (ASA24) Dietary Assessment Tool to assess typical dietary intake and diet quality (using HEI-202075) during week 1, 4, 8, and 12 of the study period. This food record can be completed at participants' homes via a computer, ipad or smartphone.