Re. Schoen et al., SAGITTAL DIAMETER IN COMPARISON WITH SINGLE SLICE CT AS A PREDICTOR OF TOTAL VISCERAL ADIPOSE-TISSUE VOLUME, International journal of obesity, 22(4), 1998, pp. 338-342
BACKGROUND: Abdominal obesity has an important biological and epidemio
logical relationship to disease. The gold standard for measurement of
visceral adipose tissue (VAT) is assessment by computerized tomography
(CT) or magnetic resonance imaging (MRI), but because of simplicity a
nd ease in collection, anthropometric variables are a desirable altern
ative to estimate VAT. OBJECTIVE: To compare the abilities of a single
slice CT scan through the L4-L5 interspace (L4-L5 VAT), sagittal diam
eter, and body mass index (BMI) to estimate total volume VAT. Total vo
lume VAT (the gold standard) was measured by total abdominal CT scanni
ng, with a mean of 42 CT slices per patient. Estimation of VAT in subj
ects of similar body size was emphasized. DESIGN: Retrospective study
of subjects undergoing complete abdominal and pelvic CT scanning for c
linical reasons. SUBJECTS: 40 subjects (20 men and 20 women) mean age
56.5 y, with a balanced selection for BMI < 27 and > 27. RESULTS: In u
nivariate regression models, L4-L5 VAT explained the largest proportio
n of the variance in total VAT (R-2 = 0.87 (P < 0.001)), though age (R
-2 = 0.11 (P = 0.04)), BMI (R-2 = 0.37 (P < 0.001)), and sagittal diam
eter (R-2 = 0.50 (P < .001)) were also statistically significantly rel
ated to total VAT. When limited to individuals with a BMI greater than
or equal to 27 however, L4-L5 VAT explained a large proportion of the
variance in total VAT (R-2 = 0.87 (P < 0.001)) whereas sagittal diame
ter was only of borderline significance (R-2 = 0.20 (P = 0.06)), and B
MI was not associated with total VAT (R-2 = 0.04 (P = NS)). In multipl
e regression analyses, L4-L5 VAT area explained a large proportion of
the variance (0.84-0.90), and once in the model, BMI, sagittal diamete
r, and age did not additionally contribute significantly to the explai
ned variance in total VAT. CONCLUSIONS: Abdominal sagittal diameter is
poorly correlated to total VAT for men and women with a BMI > 27. Wit
hin a 2 cm range of sagittal diameter, there is nearly a three-fold va
riability in total VAT.