Purpose: To evaluate whether brown adipose tissue (BAT) is present in middle-aged patients with cardiovascular comorbidities and to quantify how BAT presence associates with obesity and metabolic dysfunction.
Materials and methods: Supraclavicular and subcutaneous adipose tissue fat-signal-fraction (FF) was determined with 1.5T water-fat magnetic resonance imaging (MRI) in 50 patients with coronary artery disease, cerebrovascular disease, or peripheral artery disease. The association between BAT presence, as measured by a higher FF difference between supraclavicular and subcutaneous adipose tissue, and obesity and metabolic dysfunction was quantified using multivariable linear regression.
Results: Supraclavicular adipose tissue displays a lower FF of 82.6% (interquartile range [IQR] 78.8-84.3) compared to 90.2% (IQR 87.3-91.9) in subcutaneous white adipose tissue (WAT, P < 0.0001). BAT presence was associated with less obesity and metabolic dysfunction. For example, 1 SD lower waist circumference (11.7 cm), 1 SD lower triglycerides (1.0 mmol/L), and absence of metabolic syndrome and type 2 diabetes were associated with 1.1% (95% confidence interval [CI] 0.1; 2.0), 1.1% (95% CI 0.1; 2.0), 2.1% (95% CI 0.1; 4.1), and 4.1% (95% CI 0.1; 7.1) higher FF difference between supraclavicular adipose tissue and subcutaneous WAT, respectively.
Conclusion: Supraclavicular adipose tissue has BAT characteristics in adult patients with clinical manifest cardiovascular disease and BAT presence is associated with less obesity and a more favorable metabolic profile.
Level of evidence: 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:497-504.
Keywords: DIXON chemical-shift magnetic resonance imaging; brown adipose tissue; cardiovascular disease; fat fraction; metabolic dysfunction; obesity.
© 2017 International Society for Magnetic Resonance in Medicine.