Validation of the measurement of intra-abdominal fat between ultrasound and CT scan in women with obesity and infertility

OBJECTIVE: To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT). DESIGN AND METHODS: Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle program. RESULTS: The Pearson's correlation between IAF measurement by US compared to CT was good at baseline, month 3 and 6 (all r ≥ 0.72). The correlation of SAF measurement by US compared to CT was reasonable at baseline (r = 0.54; 95%CI 0.30-0.78) and weak at month 3 and 6 (all r ≤ 0.39). The correlation between the changes in IAF over 3 and 6 months by US compared to CT was reasonable and significant respectively (all r > 0.48). US could not measure the changes of SAF over time. The Bland-Altman plot showed good agreement between US and CT for IAF measurements (-1.1 [95%CI -3.9-1.6] cm lower mean in US) at baseline. For changes of IAF over time, mean estimates were in agreement. CONCLUSION: In women with obesity and infertility, measuring IAF by US is in good agreement with the CT scan methodology but the measurement of SAF by US is unreliable.