Association of childhood growth with adult lung function: A prospective urban birth cohort study from India

Background and objectives While some studies suggest that lower birth weight is associated with poorer adult lung function, findings regarding early childhood, adolescent, and adult growth variables remain inconsistent. We conducted this study to determine whether low lung function in Indians is related to lower birthweight and early growth. Methods The New Delhi Birth Cohort (NDBC) was used as the study population to examine patterns and periods of growth in infancy, childhood, and adolescence using a conditional growth model. Lung function data were collected using spirometry and the forced oscillation technique at approximately 50 yr of age. We further examined associations of conditional size measures with adult lung function outcomes using multiple linear regression models. Results Lung function was positively associated with weight till 5 yr of age. Further, an increase of 1 standard deviation (SD) in conditional weight between 5-10 yr resulted in a decrease in forced vital capacity (FVC) of 50 mL [95% confidence interval (CI) -0.10 to 0.00 (P= 0.08)]. Between 10-50 yr of age, a negative association was observed between weight and lung function. Positive associations of some of the measures of lung function were observed with length at birth, 2 yr, adolescent height, and final adult height. An increase of 1 SD in conditional height between birth and two years resulted in an increase in forced expiratory volume in 1 second (FEV1) of 130 mL (95% CI, 0.09 to 0.17). Interpretation and conclusion Birth weight and birth length, and greater than predicted linear growth throughout childhood, are independently associated with better adult lung function, in terms of spirometry and oscillometry. It is plausible that greater than predicted weight gain after 5 yr of age or during adolescence, or adulthood has an inverse association with lung function.