Korean J Intern Med.  2021 Sep;36(5):1221-1232. 10.3904/kjim.2020.064.

Evaluation of body composition using computed tomography in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

• Ahn SS
• Yoo BW
• Kwon HC
• Yoo J
• Jung SM
• Song JJ
• Park YB
• Lee SW

• KMID: 2519798
• DOI: http://doi.org/10.3904/kjim.2020.064

Abstract

Background/Aims
Measures of body composition, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA), are considered important prognostic factors in chronic diseases. The association of these measures with auto-inflammatory disorders, such as anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), remains unclear. We investigated the clinical significance of VAT, SAT, and SMA in patients with AAV.
Methods
Patients with AAV subjected to chest computed tomography (CT), abdominal CT, or positron emission tomography-CT on diagnosis of AAV were evaluated. Quantitative assessment of VAT, SAT, and SMA was performed at the third lumbar vertebral level and computed by summing the pixel attenuation for tissue-specific Hounsfield units in the corresponding region. Associations of VAT, SAT, and SMA with clinical and laboratory data and clinical outcome measures were evaluated.
Results
Of the 117 patients, 61 (52.1%) were classified as having microscopic polyangiitis, 28 (23.9%) as granulomatosis with polyangiitis, and 28 (23.9%) as eosinophilic granulomatosis with polyangiitis. VAT significantly correlated with age, weight, body mass index (BMI), and Birmingham Vasculitis Activity Score, whereas SAT correlated with weight, BMI, and creatinine levels. A significant association was found between SMA and age, height, weight, BMI, and the Five-Factor Score. Cox proportional hazards analysis showed that creatinine levels (odds ratio [OR], 1.346; 95% confidence interval [CI], 1.034 to 1.753; p = 0.027) and high VAT (OR, 7.137; 95% CI, 1.343–37.946; p = 0.021) were independently associated with all-cause mortality during follow-up.
Conclusions
Evaluation of VAT using CT is useful for estimating disease activity and all-cause mortality in patients with AAV.

Keyword

Body composition; Computed tomography; Prognosis; Anti-neutrophil cytoplasmic antibody-associated vasculitis; Visceral adipose tissue