Brown adipose tissue may not be associated with cachexia, according to an article published by Eljalby et al in the American Journal of Physiology Endocrinology and Metabolism. The findings also suggested that brown adipose tissue does not increase cancer mortality.
Background
Brown adipose tissue has been linked to many health benefits—such as lower rates of heart disease, diabetes, and high blood pressure. Yet, some cancer studies in mice suggest brown adipose tissue may lead to cachexia. In a new study, researchers investigated if the same is true in humans.
Study Methods and Results
In the new study, the researchers studied over 14,000 adult patients aged 18 years and older from June 2009 to March 2018. Patients who had more than one cancer diagnosis or unstageable cancers were excluded. More than 8,600 of the patients involved in the study had cachexia based on their body mass index and a previous cachexia diagnosis within 12 months of their cancer diagnosis.
The researchers revealed that patients who had cachexia were more likely to be older, male, have a greater percentage of weight loss, have a history of smoking, and self-identify as Asian or Black. Additionally, cachexia was found to be more prevalent in patients with head and neck, brain, and upper gastrointestinal tract cancers.
The researchers discovered that patients who had brown adipose tissue had a significantly lower prevalence of cachexia compared with those who didn’t have brown adipose tissue. To further test for cancer-specific associations, the researchers analyzed tumor sites from 100 patients with breast cancer, bronchus and lung cancers, and hematologic malignancies who also had brown adipose tissue in their bodies—and noted that these patients may have lower levels of inflammatory marker C-reactive proteins that are correlated with a higher rate of mortality, and brown adipose tissue may not significantly contribute to increased mortality rates.
Conclusions
“Brown [adipose tissue] is linked to a broad spectrum of health benefits in humans,” explained senior study author Paul Cohen, MD, PhD, the Albert Resnick, MD, Assistant Professor and Head of the Laboratory of Molecular Metabolism at The Rockefeller University, a senior attending physician at The Rockefeller University Hospital, and an assistant attending physician and cardiologist at Memorial Sloan Kettering Cancer Center. “We hope that our findings will increase interest in studying brown [adipose tissue] and leverage its health benefits in patients with and without cancer,” he emphasized.
The researchers concluded that although a protective association between brown adipose tissue and decreased cachexia and mortality was observed in the new study—and may be more likely than a detrimental effect—further prospective studies may be needed to clarify the relationship between the brown adipose tissue and cachexia.
Disclosure: For full disclosures of the study authors, visit journals.physiology.org.
