Lung Diffusing Capacity at Age 22 and its Life-Course Determinants: Evidence from the 1993 Pelotas Birth Cohort

We investigated DLCO parameters at 22 years and associations with socio-demographic, health, and behavioral factors.

We studied a total of 3350 participants in the 22-year follow-up of the 1993 Pelotas Birth Cohort. DLCO, alveolar volume (VA), and transfer coefficient (KCO) were modeled against perinatal factors and characteristics at 22 years using crude and adjusted linear regressions, stratified by sex.

Maternal smoking during pregnancy was linked to lower DLCO (β=-1.0; 95%CI, -1.72, -0.28) and VA (β=-0.19; 95%CI, -0.33, -0.05) in men. Low birth weight showed lower DLCO (β=-1.21; 95%CI, -2.13, -0.29) and VA (β=-0.29; 95%CI, -0.47, -0.11) in women. Black participants showed lower VA in both sexes and higher KCO in men (β=0.29; 95%CI, 0.14, 0.44). Obesity linked to lower VA and higher KCO in both sexes. Male smokers ≥11cigarettes/day had lower DLCO (β=-4.80; 95%CI, -6.01, -3.59), VA (β=-0.40; 95%CI, -0.64, -0.17), and KCO (β=-0.51; 95%CI, -0.70, -0.32). Female smokers showed higher DLCO and VA but lower KCO (β=-0.25; 95%CI, -0.49, -0.01).

Pulmonary diffusing capacity is shaped by early-life factors and modifiable exposures, including tobacco smoking and obesity. After adjusting for confounders, including time since the last cigarette, to minimize bias related to the absence of hemoglobin or carboxyhemoglobin information, associations remained evident. DLCO serves as an early marker of respiratory and systemic health, supporting prevention strategies and risk stratification in young adults.