Visceral adipose tissue (VAT) is associated with abnormal cardiovascular and metabolic profiles. Total VAT volume of the abdominal compartment by MRI is the gold standard measurement for VAT but is costly and time consuming. Prior studies suggest VAT area on a single slice MR image may serve as a surrogate for total VAT volume but it is unknown if this relationship is maintained in overweight and obese males and females. Untreated sleep apnea subjects enrolled into the Icelandic Sleep Apnea Cohort underwent abdominal MRI. VAT area and subcutaneous adipose tissue (SAT) area at the L2-L3 and L4-L5 interspaces and total VAT and SAT volumes were determined by manual examination using image analysis software. N=539 males and N=129 females with mean ages of 54.1 and 58.8 years and mean body mass index of 32.2 kg/m2 and 33.7 kg/m2, respectively, were studied. Mean total VAT volume was 40% smaller and mean total subcutaneous adipose tissue (SAT) was 25% larger among females compared to males. The correlation with VAT volume was significantly larger for L2-L3 VAT area (r=0.96) compared to L4-L5 VAT area (r=0.83). The difference in correlation coefficients was statistically significant (non-parametric bootstrap p<0.001 with 95% CI for the difference from 0.11 to 0.15. VAT area at L2-L3 was also significantly better correlated with VAT volume than traditional anthropometric variables. Linear regression analyses demonstrated that L2-L3 area alone was sufficient for predicting total VAT volume and that the nature of the linear association was maintained across all levels of obesity and in both genders.

OSAS in adolescents is mediated by a combination of anatomic (ATV, NPAV) and neuromotor factors (activated Pcrit). This may have important implications for the management of OSAS in adolescents.

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