Isolated Impaired Fasting Glucose
Conditions
Keywords
Low-calorie diet, Prediabetes, Overweight, Obesity, Fasting hyperglycemia
Brief summary
This study aims to evaluate the preliminary efficacy of a low-calorie diet (LCD) intervention in addressing the underlying pathophysiological abnormalities and improving fasting hyperglycemia among individuals with isolated impaired fasting glucose (i-IFG). Additionally, it seeks to assess the feasibility and acceptability of the LCD intervention.
Detailed description
This proof-of-concept randomized controlled trial (RCT) will enroll 34 individuals aged 35-65 years with overweight or obesity and isolated impaired fasting glucose. Intervention participants will adhere to an 8-week low-calorie dietary (LCD) regimen (\ 1,320 kcal/day) comprising specific macronutrient proportions (55% carbohydrate, 13% fat, 25% protein, and 2% fiber). Control participants will maintain their habitual dietary habits and physical activity levels. Primary outcomes at 8 weeks include between-group changes in weight, fasting plasma glucose, indices of ß-cell function and hepatic insulin resistance, and alanine aminotransferase levels. Secondary outcomes are feasibility metrics (response rate, screening yield, enrollment rate, intervention compliance, cost, staff time, and retention rate) and intervention acceptability. Qualitative research will explore facilitators, barriers, acceptability, satisfaction, and participant experiences with the LCD intervention.
Interventions
BEHAVIORALLow-calorie diet
The low-calorie diet consists of approximately 1,300 kcal/day (37% carbohydrates, 25% protein, 39% fat, and 7 g of fiber per meal) over an eight-week period. Participants receive weekly pre-prepared meals from Trifecta Nutrition (Trifecta Inc. California, USA) with options for breakfast, lunch, and dinner, meticulously crafted by certified dieticians and expert chefs. Participants are encouraged to consume 1-2 liters of water daily and maintain their habitual physical activity levels.
BEHAVIORALRoutine dietary and physical activity habits
Participants are asked to maintain their habitual dietary and physical activity habits for the 8-week study period.
Sponsors
Emory University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
Nursing staff conducting outcome assessments and laboratory personnel will be blinded to participants' treatment status.
Eligibility
Sex/Gender
ALL
Age
35 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
1. Aged 35 to 65 years 2. Overweight (body mass index (BMI) ≥25 to \<29 kg/m² or ≥23 to \<29 kg/m² if Asian descent) or Obese (BMI ≥30 kg/m²) 3. Physically inactive (\<150 minutes per week of moderate-intensity physical activity or \<75 minutes per week of vigorous-intensity physical activity) 4. Prediabetes diagnosis or score ≥5 on the American Diabetes Association (ADA) risk tool
Exclusion criteria
1. Diagnosed with type 1 or type 2 diabetes 2. Cardiovascular disease (myocardial infarction, stroke, angina, heart failure, or other cardiac conditions) 3. Chronic kidney disease 4. Chronic liver disease (e.g., cirrhosis) 5. Cancers 6. Acute inflammatory bowel disease, irritable bowel syndrome, celiac disease, chronic pancreatitis, or other disorders potentially causing malabsorption 7. Food allergies 8. Participation in weight loss programs in the past six months 9. Currently following a specific diet (e.g., ketogenic diet, Mediterranean diet) 10. Participation in any exercise programs in the past six months 11. Currently taking weight-loss medications or drugs known to affect glycemia (steroids and antipsychotics) 12. Previous bariatric surgery or plan to have bariatric surgery during the study period 13. Planning to relocate during the study period 14. Intending to fast during the study period for religious or other reasons 15. Pregnancy or planning to become pregnant during the study period 16. Breastfeeding 17. Non-English speaker
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Facilitators, barriers, acceptability, satisfaction, and participant experiences with the the intervention | 4 and 8 weeks | Qualitative in-depth interviews |
| Screening yield | Baseline | Screening yield: Proportion of screened individuals meeting eligibility criteria. |
| Enrollment rate | Baseline | Enrollment rate: Proportion of eligible individuals who enroll in the study. |
| Resource utilization | Throughout the study period, an average of 10 weeks | Resource utilization: Assessment of expenditures and staff time. |
| Retention rate | 4 and 8 weeks | Retention rate: Proportion of enrolled participants who complete the study. |
| Intervention acceptability | 4 and 8 weeks | Intervention acceptability will be assessed using the Theoretical Framework of Acceptability questionnaire. Scores range from 7 to 35. Higher scores indicate better acceptability among participants. |
| Feasibility of intervention | 4 and 8 weeks | Will be assessed using the Feasibility of Intervention Measure questionnaire. Scores range from 4 to 20. Higher scores indicate better feasibility among participants. |
| Intervention appropriateness | 4 and 8 weeks | Will be assessed with the Intervention Appropriateness Measure questionnaire. Scores range from 4 to 20. Higher scores indicate better appropriateness among participants. |
| Response rate | Baseline | Response rate is defined as the proportion of individuals responding to the invitation sent via the Epic database. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fasting plasma glucose in mg/dl | 4 and 8 weeks | Will be analyzed by enzymatic assays |
| Indices of ß-cell function | 4 and 8 weeks | Will be assessed using the insulinogenic index (IGI) |
| ß-cell function assessed by Oral Disposition Index (DI(O)) | 4 and 8 weeks | Will be assessed using the Oral Disposition Index (DI(O)) |
| ß-cell function assessed by Homeostatic Model Assessment of ß-cell Function (HOMA-B) | 4 and 8 weeks | Will be assessed using the Homeostatic Model Assessment of ß-cell Function (HOMA-B) |
| Indices of hepatic insulin resistance | 4 and 8 weeks | Will be assessed using the Hepatic Insulin Resistance Index (HIRI) |
| Alanine aminotransferase (liver enzyme) in U/L | 4 and 8 weeks | Will be analyzed with colorimetric assays |
| Weight in kg | 4 and 8 weeks | Weight will be measured using a digital weighing scale with an accuracy to the nearest 0.1 kg |
Countries
United States
Contacts
Primary ContactSathish Thirunavukkarasu, PhD
Outcome results
None listed