The longitudinal association of actigraphy-estimated sleep with grief in middle-aged and elderly persons

Most people experience grief after a loss, about 10% develop complicated grief, often accompanied by sleep complaints. Yet, the role of objectively estimated poor sleep remains unclear. Therefore, we assessed the cross-sectional and longitudinal association of actigraphy-estimated sleep with grief. We included 1,776 participants (mean age: 61.8 ± 8.9 years, 55% women) of a prospective population-based cohort. Of 1,471 participants (83%) repeated measures of grief were available (median follow-up 6 years, inter quartile range 5.6–6.3). At baseline, sleep was objectively estimated using actigraphy (mean duration 6.0 ± 0.8days). At baseline and follow-up, participants were asked about significant losses and completed the Dutch Inventory of Complicated Grief (17 items, cut-off ≥22). At baseline 1,521 (86%) participants experienced no grief, 44 (2%) acute grief (<6 months, any grief score), 158 (9%) non-complicated grief (≥6 months, grief score<22), and 53 (3%) complicated grief (≥6 months, grief score≥22). In those indicating any grief (n = 255), low sleep efficiency (B = −0.16, 95%CI = −0.30;-0.02), long sleep onset latency (B = 0.07, 95%CI = 0.01; 0.14), and long wake after sleep onset (B = 0.06, 95%CI = 0.01; 0.10) were cross-sectionally associated with more grief symptoms. Over time, those with a short total sleep time (OR = 0.59, 95%CI = 0.39; 0.91), low sleep efficiency (OR = 0.95, 95%CI = 0.91; 0.99), long sleep onset latency (OR = 1.02, 95%CI = 1.00; 1.04), and long wake after sleep onset (OR = 1.02, 95%CI = 1.00; 1.03) at baseline more often experienced complicated grief than non-complicated grief at follow-up. This study suggests that objectively estimated poor sleep is associated with grief over time. Poor sleep might not only accompany grief, but also be a risk factor for developing complicated grief after a loss.