Background: Cannabis use has become common, but its effects on sleep health—an important contributor to cardiovascular health—remain poorly understood. We investigated associations between recent and cumulative lifetime cannabis use and objective and subjective sleep measures in middle-aged adults. Method: We assessed recent cannabis use (last 30 days) repeatedly from young adulthood (age 18-30 at baseline in 1985-86) to middle age (after 35 years) in the longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) study. Cumulative lifetime cannabis use (1 year = 365 days of use) was estimated by summing days of use during follow-up. At Year 35 (Y35), we obtained objective sleep measures (duration, efficiency, fragmentation, wake after sleep onset [WASO]) via 7-day wrist actigraphy from CARDIA Sleep Ancillary Study II. Subjective sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Robust regression models adjusted for Y35 age, sex, race, education, cumulative cigarette smoking, alcohol use, other substance use, physical activity, body mass index, sleep medication, and comorbidities. We also examined race, sex, and cigarette smoking status differences in associations. Result: Of 571 participants, mean age was 61.9 years; 65% were female, and 35% Black. Means (SD) for sleep duration, efficiency, fragmentation, WASO, and PSQI were 6.9 (1.1) hours, 90.5 (4.2)%, 20.6 (7.6)%, 43.5 (20.9) minutes, and 6.1 (3.6) scores, respectively. At Y35, 13.8% reported recent cannabis use, 56% reported former use, mean (SD) cumulative use was 1.6 (4.4) years. With adjustment, recent cannabis use was associated with longer sleep duration, lower efficiency, and higher WASO; former cannabis use was associated with longer sleep duration (Table). Compared to those with cumulative cannabis exposure years in the first quartile, fourth quartile users had longer sleep duration, lower efficiency, and higher WASO (β/p-value: 0.3/0.01, -1.2/0.01, and 8.9/<.001, respectively). PSQI was not associated with recent or cumulative cannabis use. Associations were similar across race, sex, and cigarette smoking status. Conclusion: Recent and cumulative lifetime cannabis use is associated with longer sleep duration and poorer sleep quality in objective, but not subjective, measures. Further longitudinal studies are needed to identify interventions aimed at improving sleep health and promoting cardiovascular health in cannabis users.
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