Morning saliva cortisol foreshadows teen tobacco use

Morning cortisol concentration in the saliva, as a biomarker of stress, is correlated with tobacco use in adolescents, a recent study has found.

The study included 381 adolescents (aged 13–14 years, 52.2 percent girls) in whom salivary cortisol was measured through an enzyme-linked immunosorbent assay. None of the participants had a history of tobacco use, and they were followed until tobacco initiation through cigarette smoking, snus use, or either. Duration of use was also measured.

Participants were then divided into quartiles of saliva cortisol levels and Poisson regression models were used to determine its association with tobacco use.

Adjusted models showed that increasing quartiles of morning cortisol was associated with a 27-percent increase in the likelihood of reporting any tobacco use within 3 years (rate ratio [RR], 1.27, 95 percent confidence interval [CI], 1.06–1.52).

Morning cortisol was also linked to cigarette (RR, 1.24, 95 percent CI, 1.00–1.53) and snus (RR, 1.33, 95 percent CI, 1.04–1.71) use.

A similar impact of morning cortisol was reported for the duration of use of cigarettes (RR, 1.22, 95 percent CI, 0.98–1.52), snus (RR, 1.40, 95 percent CI, 1.03–1.90), and overall tobacco (RR, 1.22, 95 percent CI, 1.00–1.50).

Afternoon cortisol levels were less consistently associated with tobacco use outcomes.

“The findings of this study shed light into the biological mechanisms linking stress and tobacco use,” the researchers said. “Further research should address the possible link between life-course negative events, dysregulation of the stress response system, and the onset of tobacco use in animal and epidemiologic studies that simultaneously address the role of genetic and socioenvironmental factors.”