Long-term trajectories of insomnia and their lifestyle and health correlates.

OBJECTIVES: Insomnia is highly prevalent in the general population. We aimed to identify long-term insomnia trajectories, examine baseline predictors of trajectory membership, and assess how lifestyle factors and health outcomes evolve across these trajectories. METHODS: Data were obtained from the Swedish Longitudinal Occupational Survey of Health, including 15,807 participants with repeated sleep assessments collected biennially between 2010 and 2018. Latent class trajectory modeling identified 4 distinct insomnia trajectories. Multinomial logistic regression examined baseline predictors of trajectory membership, and repeated-measures regression models assessed longitudinal associations with lifestyle factors and somatic and psychiatric morbidity. RESULTS: Four trajectories were identified as follows: low and stable, increasing, decreasing, and persistently high insomnia probability. Compared with the low and stable trajectory, all higher-risk trajectory groups at baseline consisted of a higher proportion with female sex, younger age, lower physical activity, higher body mass index, and a higher prevalence of sleep apnea and neurological and psychiatric disorders. During follow-up, body mass index increased more steeply for those in the increasing and persistently high trajectories, whereas physical activity increased in the decreasing trajectory. Individuals with persistently high insomnia trajectory also showed a more rapid increase in psychiatric disorders and sleep duration compared to those who remained free of disease. CONCLUSIONS: Higher-risk insomnia trajectories are associated with adverse lifestyle profiles and increasing morbidity over time, whereas decreasing insomnia probability is accompanied by increasing physical activity. These findings highlight the dynamic and heterogeneous nature of insomnia and the relevance of lifestyle factors and evolving morbidity in long-term insomnia patterns.