Pubertal development at age 14 is associated with male adolescents’ combustible cigarette smoking and dual use, but not with e-cigarette use – Findings from the UK Millennium Cohort Study

Background: Adolescent nicotine exposure via electronic cigarettes (e-cigarettes) is a global health concern. Pubertal development earlier than peers increases the risk of tobacco smoking compared to peers experiencing on-time or late maturation, yet relationships of pubertal timing with e-cigarettes are unknown. We examine whether early pubertal timing is associated with risk for e-cigarette use, tobacco cigarettes, or both by age 14. Methods: The Millennium Cohort Study follows a representative cohort of 18,552 9-month-old children born 2000–2002 in the United Kingdom. Our sample includes 11,445 adolescents (5697 boys, 5748 girls) classified at age 14 as early, on-time, or late in pubertal development timing (PDT) relative to same-age, same-sex peers using the Pubertal Development Scale. Outcomes were use of e-cigarettes, tobacco cigarettes, or both by age 14. We included childhood liability confounders and demographics measured from age 7–11. Results: For girls, no PDT differences in age 14 e-cigarette or tobacco cigarette use were observed. All relative to on-time PDT boys, early maturing boys’ odds of tobacco cigarette use were 59% higher (OR=1.59, 95% confidence interval (CI)=1.08,2.35), and odds of dual-use were 49% higher (OR=1.49, CI=1.11,1.99), both compared to odds of never use. Among late PDT boys, dual-use odds were lower than never use by 35% (OR=0.65, CI=0.47,0.91) and lower than e-cigarette use only by 36% (OR=0.64, CI=0.42,0.97). Conclusions: At age 14, PDT was not associated with e-cigarette use for either sex, yet it was linked with tobacco use and dual use among boys.