Trajectories of cigarette smoking in adulthood predict insomnia among women in late mid-life

Objective: To examine the relationship between trajectories of cigarette smoking among a community sample of women (N=498) with insomnia in late mid-life.

Methods: Participants were administered structured interviews at four time waves in adulthood, spanning approximately 25 years (mean ages=40, 43, 48, and 65 years). At each wave, data were collected on participants' cigarette smoking. At the most recent time wave, in late mid-life, participants reported on their insomnia (difficulty falling asleep, staying asleep, early morning wakening, and daytime consequences of these sleep problems).

Results: Growth mixture modeling extracted four trajectory groups of cigarette smoking (from mean ages 40-65 years): chronic heavy smokers, moderate smokers, late quitters, and non-smokers. Multivariate logistic regression analysis then examined the relationship between participants' probabilities of trajectory group membership and insomnia in late mid-life, with controls for age, educational level, marital status, depressive symptoms, body mass index, and the number of health conditions. Compared with the non-smokers group, members of the chronic heavy smoking trajectory group were more likely to report insomnia at mean age 65 (Adjusted Odds Ratio=2.76; 95% confidence interval=1.10-6.92; p<0.05).

Conclusions: Smoking cessation programs and clinicians treating female patients in mid-life should be aware that chronic heavy smoking in adulthood is a significant risk factor for insomnia.