Computed tomographic evaluation of the thymus-does obesity affect thymic fatty involution in a healthy young adult population?
- Resource Type
- Authors
- David S Kennedy; Bobby Tang; Emma Phelan; Darragh Halpenny; Kate Harrington; Conor Hickie; William C. Torreggiani
- Source
- The British journal of radiology. 91(1089)
- Subject
- 0301 basic medicine
Involution (mathematics)
Adult
Male
Population
Subcutaneous Fat
Physiology
Thymus Gland
Overweight
Subcutaneous fat
030218 nuclear medicine & medical imaging
Computed tomographic
Body Mass Index
03 medical and health sciences
Young Adult
0302 clinical medicine
Hounsfield scale
Medicine
Humans
Radiology, Nuclear Medicine and imaging
Obesity
Young adult
education
Retrospective Studies
education.field_of_study
business.industry
The role of imaging in obesity special feature: Full paper
General Medicine
medicine.disease
030104 developmental biology
Adipose Tissue
Female
medicine.symptom
business
Tomography, X-Ray Computed
- Language
- ISSN
- 1748-880X
OBJECTIVE: To determine a relationship between increased body mass index (BMI) and fatty involution of the thymus in subjects aged between 20 and 30 years. METHODS: CT images of 94 patients aged between 20 and 30 years were reviewed. Quantitative thymic mean attenuation was recorded and qualitative thymic attenuation was assigned to 1 of 4 possible grades. BMI and subcutaneous fat thickness were documented. Correlations between thymic attenuation, and BMI and subcutaneous fat thickness were assessed using linear regression models. Differences in thymic attenuation in overweight vs normal weight patients were assessed using t-test and Pearson Χ(2) analysis. RESULTS: Low mean thymic attenuation values were associated with higher patient BMI (p = 0.024). Normal weight patients had a mean quantitative thymic attenuation of 15.5 Hounsfield unit and overweight patients had a mean quantitative thymic attenuation of −16.4 Hounsfield unit (p = 0.0218). There was a significant association between increasing subcutaneous fat thickness and reduced mean quantitative thymic attenuation (p < 0.0001). There was also a significant difference in subcutaneous fat thickness when comparing qualitatively assessed thymic Grade 0 with grades 2 and 3 (p = 0.027 and 0.001 respectively); and Grade 1 with Grade 3 (p = 0.001). CONCLUSION: In patients between 20 and 30 years old, the degree of thymic fatty infiltration is related to BMI. ADVANCES IN KNOWLEDGE: Multidetector CT can assess fatty involution of the thymus gland. This retrospective study demonstrates a relationship between BMI and thymus gland fatty involution. Subjects with increased subcutaneous fat have decreased mean thymus gland attenuation.