Validity of visceral adiposity estimates from DXA against MRI in Kuwaiti men and women

OBJECTIVES The prevalence of obesity and diabetes in the Middle East is among the highest in the world. Valid measures of abdominal adiposity are essential to understanding the metabolic consequences of obesity. Dual-energy X-ray absorptiometry (DXA) is increasingly being utilised to assess body composition in population studies, and has recently been used to estimate visceral adipose tissue (VAT). The aim of this study was to determine the accuracy of DXA-derived VAT in a Middle Eastern population using magnetic resonance imaging (MRI) as the criterion measure. METHOD VAT was estimated from abdominal DXA measures in 237 adult men (n=130) and women (n=107), aged 18-65 years, participating in the Kuwait Wellbeing Study. These estimates were compared with MRI measures of the corresponding anatomical region. The agreement between methods was assessed using Bland-Altman as well as correlation analysis. RESULTS Median MRI VAT was 1148.5 cm3 (95% confidence interval: 594.2-1734.6) in men and 711.3 cm3 (95% confidence interval: 395.5-1042.8) in women. DXA estimates of VAT showed high correlations with corresponding MRI measures (r=0.94 (P<0.0001) in men; r=0.93 (P<0.0001) in women). DXA overestimated VAT with a mean bias (95% limits of agreement) of 79.7 cm3 (-767 to 963) in men and 46.8 cm3 (-482 to 866) in women. The imprecision of DXA increased with increasing VAT level in both men and women. CONCLUSION DXA estimates of VAT are valid for use in Middle Eastern populations, although accuracy decreases with increasing level of visceral adiposity.