Spirometric Reference Values from a Sample of the General U.S. Population

TLDR

Differences in body build, such as shorter stature in Mexican‑Americans and a smaller trunk:leg ratio in African‑Americans, may partly explain observed spirometric disparities. Spirometric reference values for Caucasians, African‑Americans, and Mexican‑Americans aged 8–80 were derived from 7,429 asymptomatic lifelong nonsmokers using ATS‑recommended spirometry and a piecewise polynomial model with age and height as predictors. Caucasian subjects had higher mean FVC and FEV1 than Mexican‑American and African‑American subjects, though height‑matched Caucasians and Mexican‑Americans had similar values, and the resulting reference values span a wide age range for the three groups and are useful for diagnosis and research.

Abstract

Spirometric reference values for Caucasians, African-Americans, and Mexican-Americans 8 to 80 yr of age were developed from 7,429 asymptomatic, lifelong nonsmoking participants in the third National Health and Nutrition Examination Survey (NHANES III). Spirometry examinations followed the 1987 American Thoracic Society recommendations, and the quality of the data was continuously monitored and maintained. Caucasian subjects had higher mean FVC and FEV1 values than did Mexican-American and African-American subjects across the entire age range. However, Caucasian and Mexican-American subjects had similar FVC and FEV1 values with respect to height, and African-American subjects had lower values. These differences may be partially due to differences in body build: observed Mexican-Americans were shorter than Caucasian subjects of the same age, and African-Americans on average have a smaller trunk:leg ratio than do Caucasians. Reference values and lower limits of normal were derived using a piecewise polynomial model with age and height as predictors. These reference values encompass a wide age range for three race/ethnic groups and should prove useful for diagnostic and research purposes.