Self-reported sleep relates to hippocampal atrophy across the adult lifespan – results from the Lifebrain consortium

Abstract

BackgroundPoor sleep is associated with multiple age-related neurodegenerative and neuropsychiatric conditions. The hippocampus plays a special role in sleep and sleep-dependent cognition, and accelerated hippocampal atrophy is typically seen with higher age. Hence, it is critical to establish how the relationship between sleep and hippocampal volume loss unfolds across the adult lifespan.MethodsSelf-reported sleep measures and MRI-derived hippocampal volumes were obtained from 3105 cognitively normal participants (18-90 years) from major European brain studies in the Lifebrain consortium. Hippocampal volume change was estimated from 5116 MRIs from 1299 participants, covering up to 11 years. Cross-sectional analyses were repeated in a sample of 21390 participants from the UK Biobank.ResultsThe relationship between self-reported sleep and age differed across sleep items. Sleep duration, efficiency, problems, and use of medication worsened monotonously with age, whereas subjective sleep quality, sleep latency, and daytime tiredness improved. Women reported worse sleep in general than men, but the relationship to age was similar. No cross-sectional sleep – hippocampal volume relationships was found. However, worse sleep quality, efficiency, problems, and daytime tiredness were related to greater hippocampal volume loss over time, with high scorers showing on average 0.22% greater annual loss than low scorers. Simulations showed that longitudinal effects were too small to be detected as age-interactions in cross-sectional analyses.ConclusionsWorse self-reported sleep is associated with higher rates of hippocampal decline across the adult lifespan. This suggests that sleep is relevant to understand individual differences in hippocampal atrophy, but limited effect sizes call for cautious interpretation.

Longitudinal association between hippocampus atrophy and episodic‐memory decline in non‐demented APOE ε4 carriers

“…Because FreeSurfer is almost fully automated, to avoid introducing possible study‐specific biases, gross quality control measures were imposed and no manual editing was done. To assess the influence of scanner on hippocampal volume estimates, seven participants were scanned on seven different Lifebrain scanners 26 . As reported in, 26 there was a significant main effect of scanner on hippocampal volume (F = 4.13 [2.1, 30], P = .046) in this sample.…”

“…To assess the influence of scanner on hippocampal volume estimates, seven participants were scanned on seven different Lifebrain scanners 26 . As reported in, 26 there was a significant main effect of scanner on hippocampal volume (F = 4.13 [2.1, 30], P = .046) in this sample. However, the between‐participant rank order was almost perfectly retained between scanners.…”

“…The sample was derived from the European Lifebrain project ( 17 ; http://www.lifebrain.uio.no). In the present analyses, individuals from six studies within four sites 18–25 were included (Table 1, see also Supplementary material or 26 for the inclusion criteria for each study). Healthy non‐demented study participants at least 55 years old at first measurement occasion with both memory and hippocampus measurements available (“baseline” in what follows) and with at least two memory and hippocampus measurements at least 2 years apart were included.…”

“…For description of the relation between the longitudinal observations and age, we used the linear mixed‐effect model with a linear term for age and a random intercept for each subject and generalized additive mixed model (GAMM, 28 using gamm4 R package 29 ) with a semiparametric term for age and a random intercept for each subject 26 . Akaike information criterion, bayesian information criterion, and likelihood ratio tests were used to compare the GAMM and the linear mixed effect model fit to the observed data (see Supplementary materials for details on fitting and R code).…”

Self-Reported Sleep Relates to Microstructural Hippocampal Decline in β-Amyloid Positive Adults Beyond Genetic Risk

“…To test the relationship between the relevant sleep variable (see below for selection criteria) and memory change, we also included data from the Lifebrain consortium (http://www.lifebrain.uio.no/) 15 , an EU-funded (H2020) project including participants from several major European brain studies: Berlin Study of Aging-II (BASE-II) 45,46 , the BETULA project 47 , University of Barcelona brain studies [48][49][50] , and Whitehall-II 51 , yielding a total of 1196 participants. The samples and procedures used are described in detail elsewhere 8 . The data available in all projects were (i) self-reported sleep scores from one time point, and (ii) memory change score between two time points.…”