Brown Fat Tissue Related Hormone Levels in Metabolically Healthy and Unhealthy Obese Individuals

Comparison of Brown Fat Tissue-related Hormone Levels in Metabolically Healthy and Unhealthy Obese Individuals

There are two types of adipose tissue in humans, white and brown adipose tissue. While the main task of white adipose tissue is energy storage, the main task of brown adipose tissue is energy expenditure. It was previously thought that only infants have brown adipose tissue, however today it is known that metabolically active brown adipose tissue exists in adult humans as well. Brown adipose tissue contributes to metabolic health through both energy expenditure and the cytokines they secrete.

Although obesity is frequently associated with many metabolic dysfunctions and cardiometabolic diseases such as insulin resistance, prediabetes, atherogenic dyslipidemia, metabolic syndrome, some obese individuals have been defined as metabolically healthy obese. The mechanisms underlying the formation of the metabolic healthy obese phenotype are not well understood. In experimental animal studies, it has been suggested that the molecular phenotype of adipose tissue is an important factor affecting metabolic health in obese individuals. One of the most important factors affecting the molecular phenotype of adipose tissue is the browning potential of adipose tissue. Based on this hypothesis, in this study it is aimed to investigate whether the browning of white adipose tissue has an effect on determining the metabolic phenotype of metabolically healthy and unhealthy obese individuals with the same amount of adipose tissue.

It is known that irisin, FGF21 and NRG4 are hormones that have the ability to brown the white adipose tissue. In our study, it was aimed to investigate whether there is a difference in serum FGF21, irisin and Neuregulin4 (NRG4) levels, which have brown adipose tissue browning potential, in metabolically healthy and unhealthy obese. In this way, it will be found out whether serum FGF21, irisin and NRG4 hormones, which have a browning effect on white adipose tissue, have an effect on the metabolic health of obese individuals and whether these hormones can be a treatment target.

In this project, participants who have BMI ≥30 kg/m2 and no criteria other than metabolic syndrome criteria, except increased waist circumference (blood pressure ≥130/85 mmHg, fasting blood glucose ≥100 mg/dl, triglyceride ≥150 mg/dl, HDL <40mg/dl in men, <50 mg/dl in women) and those without prediabetes will be defined as metabolically healthy obese, on the other hand other obese individuals will be defined as metabolic unhealthy. 10 ml blood samples will be taken from at least 60 metabolically healthy and 60 metabolically unhealthy participants. Serum FGF21, irisin and NRG4 levels will be measured and their levels in metabolically healthy and unhealthy obese individuals will be compared.

Study Overview

• Status: Completed
• Conditions: Metabolically Healthy Obesity
• Intervention / Treatment: Diagnostic test: metabolically healthy obese

• Study Type: Observational
• Enrollment (Actual): 104

Contacts and Locations

Study Locations

• Turkey
  • Istanbul, Turkey
    • Istanbul Medeniyet University Goztepe Prof Dr Suleyman Yalcın City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

individuals who attend to the hospital's obesity outpatient clinics.

Description

Inclusion Criteria:

• Body mass index ≥30
• Body fat percentage ≥30% in women, ≥25% in men

Exclusion Criteria:

• antidiabetic medication usage
• antihypetrensive mediaction usage
• lipid lowering medication usage
• pregancy
• hypo/hyperthyroidism
• steroid usage
• benign/ malign tumor diagnosis
• liver disease
• secondary causes of obesity

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
metabolically healthy obese individuals; Individuals who have a body mass index equal or higher than 30 kg/m2, no medication usage, who have only high waist circumference without any other metabolic syndrome criteria.	Diagnostic test: metabolically healthy obese; Obese individuals will be divided into 2 groups as metabolic healthy and unhealthy obese, and their batokine concentrations will be compared.; Other Names: metabolically unhealthy obese
metabolically unhealthy obese individuals; Individuals who have a body mass index equal or higher than 30 kg/m2, no medication usage, who have more than one metabolic syndrome criteria (as defined below) including high waist circumference.	Diagnostic test: metabolically healthy obese; Obese individuals will be divided into 2 groups as metabolic healthy and unhealthy obese, and their batokine concentrations will be compared.; Other Names: metabolically unhealthy obese

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Specific batokine concentrations in metabolically healthy end unhealthy obese individuals.	The participants' irisin, FGF-21 and NRG-4 levels will be measured to compare their concentrations in metabolically healthy and unhealthy obese individuals.	1 year

Collaborators and Investigators

• Sponsor: Istanbul Medeniyet University
• Investigators: Principal Investigator: Hicran Mutlu, Assoc. Prof., Istanbul Medeniyet University Goztepe Prof Dr Suleyman Yalcın City Hospital

Publications and helpful links

General Publications

• White JD, Dewal RS, Stanford KI. The beneficial effects of brown adipose tissue transplantation. Mol Aspects Med. 2019 Aug;68:74-81. doi: 10.1016/j.mam.2019.06.004. Epub 2019 Jun 21.

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2021
• Primary Completion (Actual): December 1, 2022
• Study Completion (Actual): February 1, 2023

Study Registration Dates

• First Submitted: January 13, 2022
• First Submitted That Met QC Criteria: February 9, 2022
• First Posted (Actual): February 10, 2022

Study Record Updates

• Last Update Posted (Actual): May 19, 2023
• Last Update Submitted That Met QC Criteria: May 18, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: FGF21; irisin; metabolically healthy obese; NRG4
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity; Obesity, Metabolically Benign
• Other Study ID Numbers: Batokines-09

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: not yet decided

Drug and device information, study documents

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