Skip to main content
OpenTrials
Completed

NCT Number: NCT03675360

Low-Carbohydrate Dietary Pattern on Glycemic Outcomes Trial

The proposed randomized controlled trial will test the effect of a low-carbohydrate diet on hemoglobin A1c among individuals with elevated hemoglobin A1c that are within the range of prediabetes or diabetes. Results may provide evidence about the role of carbohydrate restriction in individuals with or at high risk of type 2 diabetes.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Diabetes Diabetes Mellitus Diet Modification Endocrine System Diseases Glucose Intolerance Glucose Metabolism Disorders Glucose Metabolism Disorders (Including Diabetes Mellitus) Hyperglycemia Metabolic Disease Metabolic Diseases Nutritional and Metabolic Diseases PreDiabetes Prediabetic State

Age range

40 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tulane Office of Health Research

New Orleans, Louisiana, 70112, United States

About this study

In the short-term, among patients with type 2 diabetes, low-to-moderate carbohydrate diets have a greater glucose-lowering effect than do high-carbohydrate diets. However, compared with usual diet, the effect of a behavioral intervention promoting a low-carbohydrate/high-unsaturated fat and high-protein dietary pattern among individuals with prediabetes or untreated type 2 diabetes is not well understood.

The overall goal of this randomized controlled trial is to study the effect of a behavioral intervention promoting a low-carbohydrate/high-unsaturated fat and high-protein dietary pattern compared with usual diet on hemoglobin A1c (HbA1c) and other metabolic risk factors among individuals with or at high risk of diabetes (HbA1c 6.0-6.9%).

A total of 150 participants with HbA1c 6.0-6.9% will be recruited and randomly assigned to either a 6-month behavioral modification program designed to reduce carbohydrate intake (initial target <40 g digestible carbohydrates, final target <60 g digestible carbohydrates) or to usual diet in a 1:1 randomization ratio.

The primary outcome will be the difference between the active intervention and control groups for change in HbA1c from baseline to 6 months. Secondary outcomes will be fasting glucose, systolic blood pressure, total-to-high-density lipoprotein-cholesterol ratio, and body weight.

Findings from this study may provide evidence about the role of carbohydrate restriction in individuals with or at high risk of type 2 diabetes.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Men or women ages 40 to 70 years
  • HbA1c 6.0-6.9%
  • Willing and able to provide informed consent

Exclusion criteria

  • Diagnosed type 1 diabetes mellitus
  • Use of agents affecting glycemic control (medications for diabetes, oral glucocorticoids) within the past three months prior to enrollment
  • Medical condition in which low-carbohydrate diet may not be advised: estimated glomerular filtration rate (eGFR) ≤45 mL/min/1.73 m²; self-report of liver disease due to hepatitis or alcohol; osteoporosis; untreated thyroid disease; gout; cancer (other than non-melanoma skin cancer) requiring treatment in the past year, unless prognosis is excellent
  • Factors that may affect HbA1c: hemoglobin <11 mg/dL (cutpoint for moderate-to-severe anemia, which could lead to falsely elevated or lowered HbA1c); recent blood donation or blood transfusion (self-report, past 4 months); human immunodeficiency virus (self-report)
  • Self-reported history of intensive care unit stay due to Coronavirus Disease 2019 (COVID-19) in the past three months, as severe COVID-19 may affect blood glucose levels
  • Allergies to nuts
  • For women, current pregnancy, breastfeeding, or plans to become pregnant during the study
  • Consumption of ≥21 alcoholic drinks per week or consumption of ≥6 drinks per occasion
  • Current or planned residence making it difficult to meet trial requirements (due to distance from study site and/or challenges regularly traveling to site)
  • Current participation in another lifestyle intervention trial or a pharmaceutical trial
  • Participation of another household member in the study; employees or persons living with employees of the study
  • Other concerns regarding ability to meet trial requirements, at the discretion of the principal investigator or study coordinator

Treatment and study plan

Low-Carbohydrate Diet

Behavioral

Behavioral modification to reduce carbohydrate consumption. Target <40 g net carbohydrates per day for first 3 months; <60 g net carbohydrates per day for months 4 onwards. The intervention will consist of 4 weekly individual counseling sessions, followed by 4 group sessions held every other week, with phone follow-ups in between group sessions. For the last 3 months of the study, there will be 3 monthly group sessions and 3 telephone follow-ups.

At baseline, participants will receive written information with standard physical activity recommendations.

Primary outcomes

  1. Change in Hemoglobin A1c

    Time frame: Baseline and six months

    6-month change in Hemoglobin A1c comparing low-carbohydrate arm with usual diet arm

Secondary outcomes

  1. Change in Fasting Plasma Glucose

    Time frame: Baseline and six months

    6-month change in fasting plasma glucose comparing low-carbohydrate arm with usual diet arm

  2. Change in Systolic Blood Pressure

    Time frame: Baseline and six months

    6-month change in systolic blood pressure comparing low-carbohydrate arm with usual diet arm

  3. Change in Total-to-HDL-cholesterol Ratio

    Time frame: Baseline and six months

    6-month change in total-to-HDL-cholesterol ratio comparing low-carbohydrate arm with usual diet arm

  4. Change in Body Weight

    Time frame: Baseline and six months

    6-month change in body weight comparing low-carbohydrate arm with usual diet arm

Other outcomes

  1. Change in Insulin

    Time frame: Baseline and six months

    6-month change in fasting insulin comparing low-carbohydrate arm with usual diet arm

  2. Change in Homeostasis Model Assessment of Insulin Resistance (HOMA-IR)

    Time frame: Baseline and six months

    6-month change in HOMA-IR comparing low-carbohydrate arm with usual diet arm. HOMA-IR was calculated as fasting insulin (μIU/mL) x fasting glucose (mmol/L)/22.5.

  3. Change in Diastolic Blood Pressure

    Time frame: Baseline and six months

    6-month change in diastolic blood pressure comparing low-carbohydrate arm with usual diet arm

  4. Change in Waist Circumference

    Time frame: Baseline and six months

    6-month change in waist circumference comparing low-carbohydrate arm with usual diet arm

  5. Change in Estimated Atherosclerotic Cardiovascular Disease Risk

    Time frame: Baseline and six months

    6-month change in estimated 10-year atherosclerotic cardiovascular disease risk comparing low-carbohydrate arm with usual diet arm.

    The estimated 10-year cardiovascular disease risk was assessed by 2013 American College of Cardiology/American Heart Association Atherosclerotic Cardiovascular Disease Risk Score, known as the Pooled Cohort Equations. The Pooled Cohort Equations estimate the 10-year primary risk of ASCVD (atherosclerotic cardiovascular disease) among patients without pre-existing cardiovascular disease who are between 40 and 79 years of age. Variables included in the risk score include: gender, age, race, total cholesterol, HDL cholesterol, systolic blood pressure, treatment for blood pressure, diabetes, and smoking status.

    Reference: Goff DC, Lloyd-Jones DM et al. 2013 ACC/AHA guideline on the assessment of cardiovascular risk: A report of the American college of cardiology/American heart association task force on practice guidelines. Vol. 129, Circulation. 2014.

Sponsors and collaborators

Lead sponsor

Tulane University School of Public Health and Tropical Medicine

Other

Collaborators

  • National Institute of General Medical Sciences (NIGMS)

Registry information

Acronym: ADEPT

Important dates

Study start
2018
Primary completion
2021
Study completion
2021
First posted
Sep 18, 2018
Registry last updated
Mar 1, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.