Brown Fat Tissue Related Hormone Levels in Metabolically Healthy and Unhealthy Obese Individuals
Condition: Metabolically Healthy Obesity
MeSH terms: Obesity, Metabolically Benign
Study type: Observational

Summary: 
      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.
    


Intervention name(s): metabolically healthy obese
Intervention type(s): Diagnostic Test
Intervention description(s): Obese individuals will be divided into 2 groups as metabolic healthy and unhealthy obese, and their batokine concentrations will be compared.
Other intervention name(s): metabolically unhealthy obese
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        individuals who attend to the hospital's obesity outpatient clinics.
      
Biospecimen description: 
      blood samples to assess irisin, FGF-21 and NRG4 concentrations
    
Keywords: metabolically healthy obese; irisin; FGF21; NRG4