Exercise-induced effects on UCP1 expression in classical brown adipose tissue: a systematic review

Area of Science:

• Physiology
• Metabolism
• Adipose Tissue Biology

Background:

• Understanding thermogenic activity is crucial for whole-body energy balance.
• Uncoupling protein 1 (UCP1) in classical brown adipose tissue (CBAT) plays a key role in thermogenesis.
• The impact of exercise on UCP1 expression requires systematic evaluation.

Purpose of the Study:

• To systematically review experimental evidence on the effect of regular exercise training on UCP1 expression in CBAT.
• To synthesize findings regarding exercise-induced changes in brown adipose tissue thermogenic potential.

Main Methods:

• Literature search of PubMed, Scopus, and EMBASE (1966-2016).
• Inclusion of studies examining exercise training and UCP1 expression in CBAT only.
• Exclusion of reviews, editorials, and conference proceedings.
• Risk of bias and quality of reporting assessed using SYRCLE and ARRIVE tools.

Main Results:

• Nine studies met the inclusion criteria.
• Regular exercise training was not found to be a major stimulus for UCP1 expression in CBAT.
• Exercise may induce adaptive responses in CBAT thermogenesis under specific conditions (high-fat diet, cold exposure, low endogenous UCP1 levels).

Conclusions:

• Regular exercise training does not significantly upregulate UCP1 expression in classical brown adipose tissue.
• Exercise-induced thermogenic adaptations in CBAT are context-dependent.
• Inconsistencies in study results may stem from confounding factors, bias, and reporting quality.