A Comparison of Vital Capacity between Normal Weight and Underweight Women in their 20s in South Korea

[Purpose] The aim of this study was to compare the vital capacity (FVC, FEV1, MVV) of normal and underweight women in their 20s. [Subjects] Thirty-four healthy non-smoking young women (age 20–25 years) participated in this study. [Methods] Based on body mass index (BMI), subjects were divided into two groups: the normal weight group (n=18, 18.5<BMI≤25.0) and the underweight group (n=16, BMI≤18.5). FVC, FEV1 and MVV were measured using a respiratory function instrument, Spiropalm (A-M systems, USA), which fulfills the American Thoracic recommendation for diagnostic spirometry. The independent t-test was used to compare vital capacities (FVC, FEV1 and MVV) between the normal and underweight group. [Results] The underweight group had significantly lower FVC and FEV1 than the normal weight group. MVV of the underweight group was also lower than that of the normal weight group, but the difference was not significant. [Conclusion] Our results indicate that low body weight is related to reduction of vital capacity in women. These results also suggest that the maintenance of adequate body weight may be important for improving the vital capacity of women.