Associations of childhood smoking initiation age with cardiometabolic multi-morbidity and mortality: a multi-national cohort study

Initiating smoking in early childhood (before age 10) significantly associate with long-term risks of heart disease, diabetes, and premature mortality for older adults, and influences the progression toward cardiometabolic multi-morbidity. Our findings highlight the importance of targeting younger children, beyond current adolescent-focused tobacco intervention strategies. We also emphasize the necessity for early-life smoking prevention, which could substantially reduce the future burden of chronic diseases and associated healthcare expenditures globally. In addition, promoting smoking cessation at any stage of life, particularly among current smokers, remains critical, as quitting smoking can meaningfully lower health risks and improve long-term outcomes.