Metabolically active brown adipose tissue in PPGL: an observational cohort study

Area of Science:

• Endocrinology
• Nuclear Medicine
• Oncology

Background:

• Brown adipose tissue (BAT) activation is increasingly recognized for its role in metabolic health and disease.
• Its association with endocrine tumors like phaeochromocytoma/paraganglioma (PPGL) remains underexplored.
• FDG-PET imaging is a key tool for assessing BAT activity.

Purpose of the Study:

• To investigate the prevalence and clinical significance of activated brown adipose tissue (aBAT) in patients diagnosed with PPGL.
• To explore the relationship between aBAT and clinical, biochemical, and genetic factors in PPGL.

Main Methods:

• Retrospective analysis of FDG-PET scans from 62 PPGL patients (2013-2021).
• Assessment of patient demographics, biochemistry (including catecholamines), radiological findings, and mutational status.
• Statistical analysis, including multivariate analysis and Kaplan-Meier survival plots, to identify associations with aBAT.

Main Results:

• 13% of PPGL patients exhibited aBAT on FDG-PET imaging.
• Elevated plasma normetanephrine concentrations were significantly associated with the presence of aBAT.
• No significant differences were observed in BMI, age, sex, or mutational status between aBAT-positive and aBAT-negative groups.
• Overall and progression-free survival did not show statistical significance between groups.

Conclusions:

• BAT activation is present in a subset of PPGL patients and is strongly linked to elevated normetanephrine levels.
• aBAT may serve as a potential imaging biomarker for severe catecholamine excess in PPGL.
• Further research is warranted to elucidate the precise role of aBAT in PPGL pathophysiology and its impact on patient outcomes.