Many studies have shown that pulmonary function differs widely among race, age and geographical residency. By virtue of the improvement of nutrition and environment, the elderly population in Korea is markedly increasing and so are the ages of patients complaining respiratory symptoms. However, we do not have our own data on the pulmonary functional reserve of elderly persons in Korea. We evaluate the deterioration of pulmonary functional reserve and standardize the predictive values of pulmonary function in the elderly population.

Pulmonary function tests were conducted in 100 men and 100 women over the age of 65. We analyzed changes of FVC and FEV1 according to age and height by linear regression. We compared our new multiple linear regression equation with other equations currently used in Korea.

In men, the mean age was 71.5±5.2(mean±SD) years and the mean height was 163.6±6.2cm. The mean FVC was 3.42±0.49ℓ and the mean FEV1, 2.72±0.40ℓ. In women, the mean age was 72.0±5.1 years and the mean height was 149.1±5.9cm. The mean FVC was 2.22±0.42ℓ and the mean FEV1, 1.83±0.34ℓ. Multiple linear regression equation using age and height as an independent factors was as follows : FVC(ℓ)=1.857-0.0356×age(year)+0.02157×height(cm) (p<0.01, R2=0.279), FEV1(ℓ)=1.340-0.02698×age(year)+0.02021×height(cm) (p<0.01, R20.255) in men, FVC(ℓ)=-0.09765-0.03332×age(year)+0.03164×height(cm) (p<0.01, R2=0.435), FEV1(ℓ)=-0.169-0.02469×age(year)+0.02539×height(cm) (p<0.01, R2=0.41) in women.

We established prediction regressions for pulmonary functional tests in the elderly Korean population. We also confirmed that currently adopted equations do not exactly anticipate the expected pulmonary functional reserve in the aged person over 65 years old. We suggest that our new equations from this study should be applied to interpret the pulmonary function tests in the elderly population in Korea.