Ethnic Differences in Adipose Tissue Dysfunction in the Development of Insulin Resistance and Type 2 Diabetes

References:

• Amati, F., Pennant, M., Azuma, K., Dubé, J.J., Toledo, F.G.S., Rossi, A.P., Kelley, D.E. and Goodpaster, B.H. (2012). Lower Thigh Subcutaneous and Higher Visceral Abdominal Adipose Tissue Content Both Contribute to Insulin Resistance. Obesity, 20(5), pp.1115-1117. doi:https://doi.org/10.1038/oby.2011.401.
• Goff, L M. "Ethnicity and Type 2 diabetes in the UK." Diabetic medicine : a journal of the British Diabetic Association vol. 36,8 (2019): 927-938. doi:10.1111/dme.13895
• Iliodromiti, S. et al. (2023) "Liver, visceral and subcutaneous fat in men and women of South Asian and White European descent: A systematic review and meta-analysis of new and published data," Diabetologia, 66(1), pp. 44-56. Available at: https://doi.org/10.1007/s00125-022-05803-5.
• Lauro, D. et al. (1998) 'Impaired glucose tolerance in mice with a targeted impairment of insulin action in muscle and adipose tissue', Nature Genetics, 20(3), p. 294. doi:10.1038/3112.
• Unamuno, X., Gómez-Ambrosi, J., Rodríguez, A., Becerril, S., Frühbeck, G. and Catalán, V. (2018). Adipokine dysregulation and adipose tissue inflammation in human obesity. European Journal of Clinical Investigation, 48(9), p.e12997. doi:https://doi.org/10.1111/eci.12997.
• Yaghootkar, H et al. "Ethnic differences in adiposity and diabetes risk - insights from genetic studies." Journal of internal medicine vol. 288,3 (2020): 271-283. doi:10.1111/joim.13082

Inclusion criteria

• Male
• Aged 18-65 years
• Self-identify as one of the following ethnic groups:

Black African/Caribbean South Asian White European

• Self-reported ancestry from the same ethnic background for at least three generations
• Body Mass Index (BMI) ≥25 kg/m² and ≤40 kg/m²
• Overweight or obese but otherwise generally healthy
• Generally healthy, with no serious long-term medical conditions or taking medications that may alter body fat distribution
• Residing in the United Kingdom
• Able to understand written and spoken English
• Able and willing to provide written informed consent
• Willing and able to comply with all study procedures, including:

• Screening assessments
• Oral Glucose Tolerance Test (OGTT)
• Blood sampling
• Magnetic Resonance Imaging (MRI)

Exclusion criteria

• Previous diagnosis of type 1 diabetes mellitus or type 2 diabetes mellitus
• HbA1c values within the diabetic range at screening
• Body Mass Index (BMI) <25 kg/m²
• Presence of chronic medical conditions known to affect:

• glucose metabolism
• insulin sensitivity
• adipose tissue distribution
• inflammatory or metabolic status
• History of cardiovascular, hepatic, renal, endocrine, or metabolic disease that may interfere with study outcomes or participant safety
• Current use of medications known to influence:

• glucose metabolism
• insulin sensitivity
• lipid metabolism
• body composition
• Current use of corticosteroids or other medications affecting metabolic function
• history of substance or alcohol misuse
• Contraindications to MRI, including:

• metallic implants
• pacemakers
• severe claustrophobia
• Inability to undergo venepuncture or cannulation procedures safely
• Participation in another clinical or interventional research study within the previous 3 months
• Inability or unwillingness to comply with study procedures or provide informed consent