BACKGROUND
Standard lifestyle interventions have shown limited efficacy in preventing type 2 diabetes among individuals with isolated impaired fasting glucose (i-IFG). Hence, tailored intervention approaches are necessary for this high-risk group.
OBJECTIVE
1) To assess the feasibility of conducting a high-intensity interval training (HIIT) study and the intervention acceptability among individuals with i-IFG, and 2) To examine the efficacy of HIIT in reducing fasting hyperglycemia and addressing the underlying pathophysiology of i-IFG.
METHODS
This study is a 1:1 proof-of-concept randomized controlled trial (RCT) involving 34 physically inactive individuals aged 35-65 years who are overweight or obese and have i-IFG. Participants identified through various sources will undergo eligibility screening via phone calls. Potentially eligible participants will be invited to the Georgia Clinical and Translational Science Alliance at Emory University Hospital in Atlanta. During their visit, they will complete questionnaires, undergo an oral glucose tolerance test, and provide blood samples for analysis of insulin and alanine aminotransferase levels. Intervention participants will engage in supervised HIIT sessions using stationary 'Spin' cycle ergometers in groups of five or fewer. They will wear continuous glucose monitoring (CGM) devices for 10 days before the intervention, throughout the 8-week intervention period, and for 10 days post-intervention. The intervention will take place three times a week for eight weeks at the Aerobic Exercise Laboratory in the Rehabilitation Hospital at Emory University. Control participants will be advised to maintain their usual physical activity levels and will also wear CGM devices for the same duration as the intervention participants. All participants will be instructed to adhere to their routine dietary habits throughout the study duration. Baseline and eight-week assessments will include measurements of weight, blood pressure, body composition, waist and hip circumferences, as well as levels of glucose, insulin, and alanine aminotransferase. Intervention participants will additionally complete an intervention acceptability questionnaire upon completion of the intervention. Outcomes will comprise feasibility parameters, intervention acceptability, and between-group changes in CGM metrics and clinical measures. Data analysis will involve descriptive statistics as well as correlation and regression analyses.
RESULTS
The study is scheduled to commence recruitment in June 2024, with the completion of follow-up assessments by the end of November 2024. We anticipate publishing the results by mid-2025.
CONCLUSIONS
The study findings are expected to guide the design and execution of an adequately powered RCT for evaluating HIIT efficacy in preventing type 2 diabetes among individuals with i-IFG.
CLINICALTRIAL
ClinicalTrials.gov ID (NCT06143345).