Deciphering the Presence of Active Interscapular Brown Adipose Tissue in Humans.

Area of Science:

• Human physiology
• Adipose tissue biology
• Metabolic research

Background:

• Brown adipose tissue (BAT) is metabolically active but its role in adult humans is unclear.
• Interscapular BAT (iBAT) is a key thermogenic depot in rodents, but its presence in adult humans is debated.
• Dorsocervical subcutaneous adipose tissue is a potential site for iBAT in humans.

Purpose of the Study:

• To review evidence for the presence and potential activity of iBAT in adult human dorsocervical adipose tissue.
• To synthesize anatomical, histological, imaging, and molecular data.
• To identify knowledge gaps and suggest future research directions.

Main Methods:

• Review of anatomical, histological, imaging (¹⁸F-FDG-PET/CT), and molecular studies.
• Analysis of gene expression and marker data.
• Consideration of findings in neonates, adults, and HIV-1-infected individuals.

Main Results:

• Dorsocervical adipose tissue is confirmed as iBAT in human neonates.
• Evidence suggests iBAT persistence in adults, especially women, based on imaging and some molecular data.
• Histological confirmation of iBAT in adults remains inconsistent, particularly in certain populations.

Conclusions:

• A dorsocervical adipose depot with BAT-like characteristics may persist into adulthood in humans, particularly women.
• Further studies, including targeted biopsies and advanced imaging, are essential to define this depot's identity (classical BAT, beige, or other).
• Clarifying the nature of this tissue is crucial for understanding human adipose tissue heterogeneity and metabolic function.