Does Mortality Risk of Cigarette Smoking Depend on Serum Concentrations of Persistent Organic Pollutants? Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) Study

Abstract

Cigarette smoking is an important cause of preventable death globally, but associations between smoking and mortality vary substantially across country and calendar time. Although methodological biases have been discussed, it is biologically plausible that persistent organic pollutants (POPs) like polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides can affect this association. This study was performed to evaluate if associations of cigarette smoking with mortality were modified by serum concentrations of PCBs and OC pesticides. We evaluated cigarette smoking in 111 total deaths among 986 men and women aged 70 years in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) with mean follow-up for 7.7 years. The association between cigarette smoking and total mortality depended on serum concentration of PCBs and OC pesticides (P value for interaction = 0.02). Among participants in the highest tertile of the serum POPs summary score, former and current smokers had 3.7 (95% CI, 1.5–9.3) and 6.4 (95% CI, 2.3–17.7) times higher mortality hazard, respectively, than never smokers. In contrast, the association between cigarette smoking and total mortality among participants in the lowest tertile of the serum POPs summary score was much weaker and statistically non-significant. The strong smoking-mortality association observed among elderly people with high POPs was mainly driven by low risk of mortality among never smokers with high POPs. As smoking is increasing in many low-income and middle-income countries and POPs contamination is a continuing problem in these areas, the interactions between these two important health-related issues should be considered in future research.

Association of Exposure to Persistent Organic Pollutants With Mortality Risk

“…We could not confirm previous observations that obesity 24 or smoking 44 modify the association of POPs with mortality. However, we did find evidence for nonlinear associations of PCBs 206, 189, and 99 with all-cause mortality.…”

Associations Between Household Pesticide Exposure, Smoking and Hypertension

“…This study found that among participants with relatively high POPs, former or current smokers had a higher risk of mortality than the never-smokers ( 14 ). The same research group further confirmed this interaction in another cohort of 70-year old participants in Sweden ( 13 ). However, the mechanisms responsible for this interaction effect have not been elucidated.…”

“…Smoking is a well-known risk factor for hypertension. Previous studies reported an interaction effect between smoking and persistent organic pollutants (POPs), PCBs, or organochlorine pesticides on mortality ( 13 , 14 ), indicating that smoking may modify the association between pesticides exposure and hypertension.…”

Concentrations of nine endogenous steroid hormones in 70-year-old men and women

“…Smoking status was defined based on self-report and categorized into current, former and never smokers (30). Plasma samples were stored at -70°C until analysis and transported between the participating centres on dry ice.…”

“…BMI was defined as body weight in kilograms divided by the squared body height in meters and was based on measurements performed at the enrolment. Smoking status was defined based on the self-report and categorized into current, former and never-smokers ( 30 ). Plasma samples were stored at −70°C until analysis and transported between the participating centere on dry ice.…”