The role of growth and nutrition in the early origins of spirometric restriction in adult life: a longitudinal, multicohort, population-based study

Spirometric restriction, defined as a reduced forced vital capacity (FVC) with a preserved FEV1/FVC ratio, is associated with increased respiratory and non-respiratory comorbidities and all-cause mortality in adulthood. Little is known about the early origins of this condition. We sought to identify early-life risk factors for spirometric restriction in adult life. In this longitudinal, multicohort, population-based study, we used data from the Tucson Children's Respiratory Study (TCRS), which recruited 1246 healthy infants at birth between April 1980, and October 1984, in Tucson, AZ, USA. Questionnaires were answered by the primary caregiver at enrolment, immediately after the child's birth, and multiple follow-up questionnaires were completed through childhood and adulthood. At the age of 22, 26, 32, and 36 years, lung function was measured with spirometry. At each survey, three mutually exclusive spirometric patterns were defined: (1) normal (FEV1/FVC ≥10th percentile and FVC ≥10th percentile); (2) restrictive (FEV1/FVC ≥10th percentile and FVC