Journal of Clinical and Diagnostic Research (May 2012)
Correlation Between Body Mass Index (BMI), Body Fat Percentage and Pulmonary Functions in Underweight, Overweight and Normal Weight Adolescents
Abstract
Introduction: In India, undernutrition coexists with obesity, thus demonstrating a “double burden of the disease.” The effect of the increased BMI and the body fat percentage on the pulmonary functions has been studied extensively. The effect of undernutrition and mild weight gain on the pulmonary functions needs attention. Objectives: The aim of this study was to investigate whether there was any correlation between the Body Mass Index, Body Fat Percentage and FVC, FEV1 and FEF25-75, in underweight, normal weight and overweight adolescents. Materials and Methods: 180 students who consisted of 90 boys and 90 girls in the age group of 18 to 21 years, who were in three BMI ranges were enrolled. They were classified into underweight, normal weight and overweight groups according to the WHO guidelines. The body fat percentage was measured by using the bioelectric impedance method and FVC, FEV1 and FEF25-75 were assessed by using MIR-SPIROLAB-II as per the ATS guidelines. Results: The mean values of FVC and FEV1 were less in the underweight and overweight subjects and the difference was significant across the BMI ranges. The FEF25-75 values were low in the overweight than in the normal weight subjects. FVC, FEV1 and FEF25-75 had a negative correlation with BMI and the body fat Percentage in males. The underweight males had a positive significant correlation between BMI, body fat percentage and FVC, FEV1 and FEF25-75. In females, only FEF25-75 had a significant correlation with BMI and the body fat percentage. Conclusion: There was a significant difference in the FVC, FEV1 and the FEF25-75 values between the underweight, normal weight and the overweight subjects. BMI as well as the body fat percentage had a significant negative correlation with FVC and FEV1 in the overweight group. A significant positive correlation was observed between BMI, body fat percentage and FCV and FEV1 . Body fat percentage had a stronger correlation than BMI. FEF25-75 had a strong negative correlation with the body fat percentage only in the overweight group.