Associations of smoking and second-hand smoke exposure with obesity and obstructive sleep apnoea risk in Tuvalu

Background: Tobacco use and second-hand smoke (SHS) exposure remain highly prevalent in Pacific Island nations, but evidence on their health consequences is limited. We aim to describe the prevalence of smoking and SHS exposure in Tuvalu, their associations with body measurements and sleep-related outcomes, and the heterogeneity by island of residence and age group. Methods: COMmunity-based Behaviour and Attitude surveys were conducted in Tuvalu between 2020 and 2025 among 4,066 participants from Funafuti and outer islands. Smoking status was assessed in all survey years, and SHS exposure was assessed in 2022, 2023, and 2025. Body composition (body mass index (BMI), waist and neck circumference) and obstructive sleep apnoea (OSA)-related outcomes in STOP-Bang scores were measured. We assessed the associations with multivariable linear and logistic regression, with stratified analyses by age group and island of residence. Current smoking (odds ratio (OR) = 1.80; 95% confidence interval (CI) = 1.30, 2.48) and SHS exposure (OR = 2.15; 95% CI = 1.54, 3.02) were associated with obesity, higher STOP-Bang scores and increased odds of STOP-Bang ≥3, which varied by island of residence. Conclusions: In Tuvalu, both active smoking and SHS exposure were associated with obesity and OSA-related outcomes, with variation by island of residence. These findings indicate the importance of strengthening the implementation and enforcement of comprehensive tobacco control for sleep health and non-communicable disease prevention in Pacific Island populations.