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.