Low-Carbohydrate Dietary Pattern on Glycemic Outcomes Trial

NCT ID: NCT03675360

Last Updated: 2023-03-01

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 150 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-09-25
• Study Completion Date: 2021-06-21

Brief Summary

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.

Detailed Description

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.

Conditions

Diabetes; PreDiabetes; Metabolic Disease; Hyperglycemia; Diet Modification; Glucose Intolerance; Glucose Metabolism Disorders (Including Diabetes Mellitus); Endocrine System Diseases

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

Low-Carbohydrate Diet

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.

Group Type: EXPERIMENTAL

Low-Carbohydrate Diet

Intervention Type: 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.

Usual Diet

No dietary intervention.

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

Group Type: NO_INTERVENTION

No interventions assigned to this group

Interventions

Low-Carbohydrate Diet

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.

Intervention Type: BEHAVIORAL

Eligibility Criteria

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

• Minimum Eligible Age: 40 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institute of General Medical Sciences (NIGMS)

NIH

Sponsor Role: collaborator

Tulane University School of Public Health and Tropical Medicine

OTHER

Sponsor Role: lead

Responsible Party

Kirsten Dorans

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Kirsten Dorans, ScD

Role: PRINCIPAL_INVESTIGATOR

Tulane University School of Public Health and Tropical Medicine

Locations

Tulane Office of Health Research

New Orleans, Louisiana, United States

Countries

United States

References

Dorans KS, Bazzano LA, Qi L, He H, Chen J, Appel LJ, Chen CS, Hsieh MH, Hu FB, Mills KT, Nguyen BT, O'Brien MJ, Samet JM, Uwaifo GI, He J. Effects of a Low-Carbohydrate Dietary Intervention on Hemoglobin A1c: A Randomized Clinical Trial. JAMA Netw Open. 2022 Oct 3;5(10):e2238645. doi: 10.1001/jamanetworkopen.2022.38645.

Reference Type: DERIVED

PMID: 36287562 (View on PubMed)

Dorans KS, Bazzano LA, Qi L, He H, Appel LJ, Samet JM, Chen J, Mills KT, Nguyen BT, O'Brien MJ, Uwaifo GI, He J. Low-carbohydrate dietary pattern on glycemic outcomes trial (ADEPT) among individuals with elevated hemoglobin A1c: study protocol for a randomized controlled trial. Trials. 2021 Feb 1;22(1):108. doi: 10.1186/s13063-020-05001-x.

Reference Type: DERIVED

PMID: 33522954 (View on PubMed)

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

P20GM109036

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2018-053

Identifier Type: -

Identifier Source: org_study_id