Background: Although childhood respiratory tract infections and low birth weight have both been associated with reduced adult lung function, little is known about the timing of these associations during life. We used data from the Newcastle Thousand Families Study to examine how these and other factors influenced FEV(1) at age 14 years and between 14 and 49 to 51 years.
Methods: Detailed information was collected prospectively during childhood. At age 14 years, 252 members of the cohort were recruited into a case-control study of respiratory health, which included measurement of FEV(1). One hundred twenty-two of these were measured again at age 49 to 51 years. Linear regression models were used to examine cross-sectional and longitudinal influences on FEV(1).
Results: Lower height (P < .001), lower BMI (P < .001), being breast fed for less than 4 weeks (P = .028), childhood history of severe respiratory illness (P = .014), childhood history of asthma (P = .004), childhood history of TB (P = .023), and birth into a lower social class (P = .049) were all significant independent predictors of lower FEV(1) at 14 years of age. Correspondingly, being a women (P < .001), and having a higher FEV(1) at age 14 years (P < .001), a lower standardized birth weight (P = .025), a greater lifetime number of cigarettes smoked (P = .007), and a childhood history of severe respiratory illness (P = .047) were all independently associated with a greater decline (or a smaller increase) in FEV(1) between age 14 and 49 to 51 years.
Conclusions: This study suggests that the change in FEV(1) between youth and middle age depends on several factors acting throughout life, including FEV(1) in adolescence, sex, cigarette smoking, birth weight, and childhood respiratory health.