Sleep Trajectories Before and After the Final Menstrual Period in The Study of Women's Health Across the Nation (SWAN).

Abstract

Longitudinal studies show that the menopausal transition (MT) is associated with poorer self-reported sleep. Increases in sleep disturbances across and beyond the MT are strongly associated with vasomotor symptoms (VMS) but occur even without VMS. We analyzed data from baseline through 13 annual or biennial follow-up assessments from SWAN's multi-racial/ethnic cohort of midlife women, specifically focusing on patterns of sleep problems in the years preceding and following the final menstrual period (FMP). The FMP demarcated the MT and the postmenopausal period. We addressed the following questions: (1) are there distinct trajectory patterns of sleep problems across the MT, and (2) do pre-FMP sleep trajectories predict sleep problems around the time of FMP (trans-FMP) and post-FMP? Group-based trajectory modeling using repeated measures log-binomial regression with generalized estimating equation methods was used to describe trajectory patterns of the most prevalent sleep problem, waking several times at least 3 nights weekly during the previous 2 weeks, in 1,285 naturally menopausal women. We found (1) 4 distinct trajectories for waking several times per night across the MT [low prevalence (n=487; 37.9%), moderate prevalence (n=365; 28.4%), increasing prevalence (n=197; 15.3%), and high prevalence (n=236; 18.4%)], (2) the prevalence of sleep problems increased overall, but in one trajectory group (increasing prevalence) more than in the other three, and (3) trouble falling asleep, early morning awakening, and frequent VMS were strongly associated with problems waking several times that persist into postmenopause. Using trajectory analysis, we showed that, in general, awakenings were stable from pre-FMP to post-FMP.