Fat Attenuation at CT in Anorexia Nervosa

Area of Science:

• Endocrinology and Metabolism
• Radiology and Imaging
• Nutritional Science

Background:

• Anorexia nervosa (AN) is associated with significant physiological changes, including alterations in body composition.
• Understanding fat depot characteristics in AN is crucial for assessing disease status and potential biomarkers.

Purpose of the Study:

• To compare fat depot composition, cross-sectional area (CSA), and attenuation between women with AN and normal-weight controls.
• To investigate the relationship between fat characteristics and hormonal correlates (estradiol, cortisol, thyroid hormones) in AN.

Main Methods:

• Computed tomography (CT) was used to quantify abdominal and thigh adipose tissue CSA and attenuation in 40 women with AN and 40 controls.
• Serum estradiol, thyroid hormones, and urinary free cortisol levels were measured.
• Statistical analyses included ANOVA and linear regression to compare groups and examine associations.

Main Results:

• Women with AN exhibited higher fat attenuation (P < .0001) and lower fat CSA (P < .0001) than controls.
• Visceral adipose tissue (VAT) attenuation, not CSA, was inversely associated with lowest prior body mass index in AN (r = -0.71, P = .006).
• Estradiol levels correlated inversely with fat attenuation and positively with fat CSA, while thyroxine and cortisol levels showed mixed associations with fat attenuation and CSA.

Conclusions:

• Women with AN demonstrate distinct fat composition with increased attenuation and reduced mass.
• VAT attenuation may serve as a biomarker for prior and current disease status in AN.
• Hormonal factors, including gonadal steroids, cortisol, and thyroid hormones, are associated with fat composition differences in AN.