Effect of body composition on ventilation parameters in a group of young Sudanese females

Abstract

Background: Lung Function Test helps (LFT) in the diagnosis and follow up of patients with pulmonary or cardiac diseases. Ignoring BMI and body composition during interpretation of LFT results may lead to wrong diagnosis and unnecessary use of drugs.

Objective: This study was conducted to test the hypothesis that differences in body composition between individuals can explain some of the features of LFT that are explained by variations in age, sex, and height only.

Methods: This observational analytical cross sectional study which included 150 young adult females. Those with history of amenorrhea, smoking, asthma or cardiac disease were excluded. Anthropometric measurements including: BMI, waist circumference (WC) and body fat percent calculated from skinfold thickness measurements were done. Dynamic spirometric tests were performed using digital spirometer; FEV₁, FVC, FEV₁% were measured.

Results: Both obese and underweight subjects had a significant reduction in FEV₁ (P = .002) and FVC (P = .004) compared to normal ones. FEV₁% was significantly higher in the overweight and obese group compared to the other two groups (P = .02). Body weight, BMI, and WC had significant positive correlation with FEV₁ and FEV₁% in young healthy females.

Conclusion: Increase in BMI, body weight, WC and body fat showed positive significant correlation with FEV₁% and may give a restrictive pattern in LFT. Underweight subjects may show significant reduction in lung function if their BMI is not considered.

Keywords: FEV₁, FVC, FEV₁%, BMI, waist circumference, Body fat %, obesity