The impact of abdominal adiposity measured by sonography on the pulmonary function of pre-menopausal females

BACKGROUND The Body Mass Index (BMI) is a widely used parameter to study obesity; however it does not assess the distribution of body adiposity. Ultrasonography is a reliable method of measuring subcutaneous (SAT), visceral (VAT) and Total adipose tissue of the abdomen (TAT) to determine the influence of abdominal fat on pulmonary function by directly measuring abdominal adipose tissue. METHODS Eighty pre-menopausal, non-smoker, sedentary females with no history of pulmonary disease were subdivided into three groups: 25 normal-weight, 28 overweight, 27 obese. Absolute and predictive spirometric values were obtained: FVC, FEV1, FEV1/FVC, IC, ERV. RESULTS A positive correlation between increased %IC and decreased %ERV was observed with increased BMI (p < 0.02; 0.001 respectively); %FVC, %FEV1 and %ERV decreased significantly as SAT (p = 0.01, p = 0.02; p < 0.001) and TAT (p = 0.01, p = 0.03, p < 0.001) increased, whereas VAT was negatively correlated only with %ERV (p < 0.001). Increments of 5 mm in TAT, VAT and SAT were followed by a reduction of 0.83 %, 0.81 %, 1.90 % in %FVC, respectively, as well as a reduction of 4.25 %, 4.31 % and 9.44 % in %ERV, respectively. CONCLUSIONS Subcutaneous abdominal adipose tissue deposition in obese females has a greater negative influence on pulmonary function than visceral adipose tissue deposition.