SENSITIVITY ASSOCIATED WITH THE IDENTIFICATION OF VISCERAL ADIPOSE-TISSUE LEVELS USING WAIST CIRCUMFERENCE IN MEN AND WOMEN - EFFECTS OF WEIGHT-LOSS

OBJECTIVE: The first objective was to determine the associated sensiti vity (true positives) and specificity (false positives) associated wit h the use of waist circumference (WC) to predict specific visceral adi pose tissue (VAT) levels. Because WC is a strong correlate of VAT, and , a WC of 100 cm and a VAT area of 130 cm(2) (L4-L5) have been suggest ed as thresholds for increased disturbances in insulin-glucose homeost asis and lipid metabolism, we assessed the sensitivity and specificity when using a WC of 100 cm to identify a VAT of 130 cm(2) or greater. A second objective was to evaluate the effects of diet and exercise in duced weight loss on VAT and WC to establish the utility of using WC t o follow reductions in VAT. RESEARCH DESIGN AND METHODS: The sensitivi ty between WC and VAT was assessed using 50 male (BMI: 30.9 +/- 4.7, a ge: 41.0 +/- 11.2 y) and 49 female (BMI: 33.3 +/- 5.0, age: 36.9 +/- 7 .4 y) subjects. The effects of weight loss on WC and VAT were evaluate d in a subgroup of 20 male and 38 female subjects. VAT was measured by magnetic resonance imaging. RESULTS: The sensitivity associated with the prediction of a VAT of 130 cm(2) or greater using a WC of 100 cm w as high (83%), however, so too was the incidence of false positives (3 8%). Significant (p < 0.01) correlations were obtained between concurr ent reductions in VAT and WC for both the male (r = 0.69) and female ( r = 0.47) groups, For the two groups combined, regression analysis ind icated that a 1 cm reduction in WC was associated with a 4% reduction in VAT mass (p < 0.01). CONCLUSIONS: The misclassification of individu als with VAT accumulation above 130 cm(2) suggest that WC alone lacks the sensitivity required to identify specific VAT values, That diet an d exercise induced reductions in visceral adiposity are positively rel ated to corresponding reductions in WC for both genders is a positive result, and demonstrates the potential utility of using WC to follow c hanges in the AT depot that conveys the greatest health risk.