Abstract
OBJECTIVES: Few prospective studies have investigated early-life tobacco smoke's effects on chronic gastrointestinal diseases (CGD) and multi-morbidity (CGM). We examined associations between early-life tobacco exposure and subsequent CGD or CGM development.</p>
STUDY DESIGN: This was a prospective cohort study conducted among UK Biobank.</p>
METHODS: We assessed the association between tobacco exposure in early life and incident CGD using UK Biobank data. We employed Cox models to estimate the risk of CGD, examining the separate and combined impacts of tobacco exposures in early life and pack-years. Multi-state Cox models further analyzed the impact of tobacco smoke on CGM progression.</p>
RESULTS: Our analysis involved 294,344 UK Biobank participants, with 61,472 developing CGD over a median observation period of 13.02 years. Prenatal tobacco exposure increased CGD risk by 11 % (HR = 1.11, 95 % CI: 1.09-1.13). Earlier smoking initiation was associated with higher CGD risk: adjusted HRs were 1.09 for adulthood, 1.16 for adolescence, and 1.25 for childhood initiation compared to never smokers (P trend <0.001). Childhood smoking initiation was linked to a 42 % increased risk of CGD in current smokers (HR = 1.42, 95 % CI: 1.31-1.53) and influenced transitions from incident CGD to CGM (HR = 1.30, 95 % CI: 1.12-1.51) and from healthy to CGM (HR = 1.83, 95 % CI: 1.58-2.13). Additionally, childhood smoking significantly raised mortality risk from all states: healthy (HR = 2.53, 95 % CI: 2.21-2.89), incident CGD (HR = 2.30, 95 % CI: 1.79-2.95), and CGM (HR = 1.67, 95 % CI: 1.13-2.46).</p>
CONCLUSIONS: Exposure to tobacco in early life increases the risk of developing CGD and elevates incidence and progress of CGM.</p>