Serum FGF21 Levels and Dietary Total Antioxidant Capacity in Type 2 Diabetes

The Effect of the Phytochemical Content and Total Antioxidant Capacity of the Diet on Serum FGF21 Levels in Type 2 Diabetes

This study aimed to evaluate the phytochemicals and total antioxidant capacity in the diets of individuals with type 2 diabetes and assess their relationship with glycemic parameters, as well as certain biochemical parameters and Fibroblast growth factor 21 (FGF21), which is an inflammatory marker. The study was conducted on a total of 80 individuals, including 40 patients with overweight or obesity (Body Mass Index (BMI) > 25 kg/m²) with type 2 diabetes aged between 18 and 64, and 40 healthy controls (BMI between 18.5-35 kg/m²). The individuals were followed for 12 weeks with an appropriate diet. Biochemical parameters, anthropometric measurements, and dietary intake records were monitored at specific intervals throughout the study. The phytochemical index and total antioxidant capacity of the individuals' diets were measured, and FGF21 was examined in the serum.

Study Overview

• Status: Completed
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Behavioral: Type 2 Diabetes Diet Modification

Detailed Description

Individuals were divided into two groups: type 2 diabetes and control. Individuals with type 2 diabetes were followed for 12 weeks with an appropriate diet specific to their condition, and necessary measurements were taken at the beginning, 4th week, and 12th week. No dietary intervention was made for the control group, and necessary measurements were taken at the beginning and 12th week. At the control points, biochemical parameters, serum samples, anthropometric measurements (body composition, weight, height, waist circumference, hip circumference), 24-hour dietary intake record, and 24-hour physical activity record were evaluated. In the experimental group, dietary intake was recorded at the beginning (week 0), 4th week, and 12th week. The dietary intake of the control group was examined at week 0 and week 12.

The "Phytochemical Index" method was used to calculate the total phytochemical intake from the diet. The total antioxidant capacity of the diet was calculated using data obtained from dietary intake records based on Ferric Reducing Ability of Plasma (FRAP), Oxygen Radical Absorbance Capacity (ORAC), Trolox Equivalent Antioxidant Capacity (TEAC), and Total Reactive Antioxidant Potential (TRAP) methods. Additionally, physical activity was determined using a recording method. Body compositions at all three control points will be determined using the bioelectrical impedance method, and waist and hip circumference measurements were taken using a non-stretchable tape measure. Routine biochemical parameters for the type 2 diabetic group (fasting blood glucose, serum lipids, HbA1c) were obtained from the records. Serum samples collected after a 10-12 hour fasting period at the beginning and 12th week were analyzed for Fibroblast growth factor 21 (FGF21) using suitable kits.

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey
  • Ankara, Turkey, 06100
    • Hacettepe University Nutrition and Dietetics Department
  • Ankara, Turkey, 06100
    • Hacettepe University Internal Medicine Department

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Study Population

The study included 38 individuals (5 male, 33 female) with type 2 diabetes who were mildly overweight or obese, aged between 19 and 64 and had a body mass index (BMI) ≥ 25 kg/m2. Additionally, 38 healthy individuals (4 male, 34 female) with a similar BMI were also included in the study.

Description

Inclusion Criteria:

• For intervention group: type 2 diabetes diagnosis
• For control group: healthy individuals
• Aged between 19 and 64
• With a body mass index over 25 kg/m²

Exclusion Criteria:

• Pregnancy
• Type 1 diabetes
• Cancer
• Chronic kidney disease
• Chronic liver disease
• Other chronic inflammatory diseases
• Individuals with HbA1c levels above 9%
• Individuals using short or medium-acting or mixed (medium+short) insulin
• Individuals with any condition that hinders physical activity
• Individuals following any weight loss diet

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Type 2 Diabetes; Individuals with type 2 diabetes were followed for 12 weeks with an appropriate diet specific to their type 2 diabetes condition, and necessary measurements were taken at the beginning, 4th week, and 12th week.	Behavioral: Type 2 Diabetes Diet Modification; A 12-week dietary intervention model was prescribed to the patients in accordance with their needs.
No Intervention: Healthy Controls; No dietary intervention was made for the control group, and necessary measurements were taken at the beginning and 12th week.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fibroblast growth factor 21 (FGF21)	FGF21 levels in serum	12 weeks
Body weight	Body weight measurements	12 weeks
Body fat percentage	Body fat percentage measured with bioelectrical impedance analysis	12 weeks
Phytochemical index	Dietary phytochemical index	12 week
Ferric Reducing Ability of Plasma (FRAP)	Dietary antioxidant capacity measured with FRAP method	12 weeks
Oxygen Radical Absorbance Capacity (ORAC)	Dietary antioxidant capacity measured with ORAC method	12 weeks
Trolox Equivalent Antioxidant Capacity (TEAC)	Dietary antioxidant capacity measured with TEAC method	12 weeks
Total Reactive Antioxidant Potential (TRAP)	Dietary antioxidant capacity measured with TRAP method	12 weeks

Collaborators and Investigators

• Sponsor: Hacettepe University
• Investigators: Principal Investigator: Zeynep Goktas, PhD, Hacettepe University

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2020
• Primary Completion (Actual): December 30, 2021
• Study Completion (Actual): April 15, 2022

Study Registration Dates

• First Submitted: June 21, 2023
• First Submitted That Met QC Criteria: June 30, 2023
• First Posted (Actual): July 10, 2023

Study Record Updates

• Last Update Posted (Actual): July 11, 2023
• Last Update Submitted That Met QC Criteria: July 10, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: type 2 diabetes; antioxidant capacity; FGF-21; phytochemical index
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: GO 20/228

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No