Estimating Waist and Hip Circumference from Routine Clinical DXA

Area of Science:

• Radiology and Medical Imaging
• Anthropometry and Body Composition
• Public Health and Epidemiology

Background:

• Waist circumference and waist:hip ratio are crucial health indicators, independent of body mass index.
• Dual-energy X-ray absorptiometry (DXA) provides site-specific soft-tissue thickness measurements.
• DXA's potential for opportunistic body circumference estimation in osteoporosis screening warrants investigation.

Purpose of the Study:

• To evaluate the correlation between DXA-derived soft-tissue thickness and directly measured body circumferences.
• To determine the variance explained by DXA measures in predicting waist circumference, hip circumference, and waist:hip ratio.
• To explore the utility of routine DXA scans for estimating body composition metrics.

Main Methods:

• Assessed correlations between DXA-derived spine and hip tissue thickness and measured circumferences in 214 women and 96 men.
• Utilized coefficient of determination (R ²) to quantify explained variance.
• Developed predictive models for waist circumference, hip circumference, and waist:hip ratio using DXA data.

Main Results:

• DXA-derived spine tissue thickness strongly predicted waist circumference (R ² 0.90 in women, 0.88 in men).
• High explained variance was observed for hip circumference (R ² 0.87 women, 0.76 men) and waist:hip ratio (R ² 0.68 women, 0.72 men).
• Final predictive models achieved adjusted R ² values of 0.91 for waist circumference, 0.86 for hip circumference, and 0.70 for waist:hip ratio.

Conclusions:

• Routine clinical DXA scans offer a viable method for estimating body circumference measurements.
• DXA-derived soft-tissue thickness can serve as a surrogate for direct circumference measurements.
• This approach facilitates opportunistic health risk assessment during osteoporosis screening.