| Summary: | BACKGROUND: Human obesity is associated with a large number or diseases and
metabolic complications such as heart disease, diabetes mellitus, hypertentension,
gallbladder disease and some types of cancer (Bjorntorp,1990; Depres et al., 1991).
Though a causative relationship has not been established between adipose tissue (AT)
distribution and these metabolic disturbances, both prospective and epidemiological
studies have demonstrated that measures of visceral adipose tissue (VAT) stores are
strong predictors of coronary heart disease, diabetes and stroke. Thus the ability to
measure abdominal AT, especially VAT, may be important in epidemiological and
clinical research. Advanced imaging techniques such as computed tomography (CT) and
magnetic resonance imaging (MRI) offer new promise for the visualization and
quantification of abdominal A T masses. However, these imaging techniques are
expensive, not generally available, and in the case of CT, expose the subjects to ionizing
radiation.
OBJECTIVE: The aim of this study was to offer a less expensive, quick, safe and
accurate method to predict VAT and body fat (BF) using measurements from dual-energy
X-ray absorptiometry (DXA) and anthropometry. Eleven men over 50 (50r69 y)
participated in this study with a wide range of Body Mass Index's. VAT, subcutaneous
abdominal adipose tissue (SAAT) and total abdominal adipose tissue (TAAT) was
measured from the 1st to the 5th.lumbar vertebrae using MRI as the criterion measure. BF
and trunk fat (TF) were also measured using DXA .
RESULTS: Measurements of TF by DXA explained about 70% of the variation in the
VAT[sub L1-L5] measured by MRI. TF measured by DXA ( x₁) in combination with the
subscapular (x₂) and sum of seven skinfolds (X3) could accurately predict the VAT[sub L1-L5]
mass measured by MRI (r² = 0.95, SEE = 8.00 %): VAT (kg) = 0.304(x₁) - 0.0526(x₂) -
0.00707(x₃) + 0.414. A single MRI scan at the L2-L3 intervertebral disk region was
found to be the best predictor of VAT[sub L1-L5] mass (r = 0.95). The waist-to-hip ratio was
highly correlated with VAT[sub L1-L5] (r = 0.83). This study also found that BF and TF
measured by DXA could be accurately predicted with the suprailiac skinfold (x₄) and
waist girth (x₅): BF (kg) = 0.341(x₄) + 0.274(x₅) - 15.5 (r² =. 0.96, SEE = 7.18 %). TF
(kg) = 0.150(x₄) + 0.199(x₅) - 9.01 (r² = 0.95, SEE = 8.80 %).
CONCLUSION: D X A combined with anthropometry can accurately predict V A T mass
from the L1-L5 vertebrae, and anthropometry alone can accurately predict BF.and TF in
men over 50 y.
|
|---|
