Diver WR, et al. - Whether secondhand smoke exposure in childhood and adulthood is associated with adult mortality among never smokers, was investigated. Findings suggested an increased risk of chronic obstructive pulmonary disease death in adulthood in relation to childhood as well as adult secondhand smoke exposure. A meaningful association of adult secondhand smoke with higher mortality from vascular disease and all causes was also reported; this finding is consistent with previous studies. Overall, secondhand smoke exposure should be reduced throughout life.

Methods

• This study included 70,900 never smoking men and women, predominantly aged ≥50 years, from the Cancer Prevention Study–II Nutrition Cohort in 1992–1993; these subjects were examined for associations of childhood and adult secondhand smoke exposure with death from all causes, ischemic heart disease, stroke, and chronic obstructive pulmonary disease.
• During follow-up through 2014, there were 25,899 participant deaths.
• Using Cox proportional hazards regression models, multivariable-adjusted hazard ratios and 95% CIs were calculated during 2016–2017.

Results

• Findings demonstrated no link between childhood secondhand smoke exposure and all-cause mortality.
• However, higher mortality from chronic obstructive pulmonary disease (hazard ratio=1.31, 95% CI=1.05, 1.65) was reported in relation to childhood secondhand smoke (living with a smoker for 16–18 years during childhood).
• Adult secondhand smoke exposure of ≥10 hours/week at enrollment was found to be related to a higher risk of all-cause (hazard ratio=1.09, 95% CI=1.04, 1.14); ischemic heart disease (hazard ratio=1.27, 95% CI=1.14, 1.42); stroke (hazard ratio=1.23, 95% CI=1.04, 1.45); and chronic obstructive pulmonary disease (hazard ratio=1.42, 95% CI=0.97, 2.09) mortality.