Poor Self-Reported Sleep is Related to Regional Cortical Thinning in Aging but not Memory Decline—Results From the Lifebrain Consortium

Abstract

We examined whether sleep quality and quantity are associated with cortical and memory changes in cognitively healthy participants across the adult lifespan. Associations between self-reported sleep parameters (Pittsburgh Sleep Quality Index, PSQI) and longitudinal cortical change were tested using five samples from the Lifebrain consortium (n = 2205, 4363 MRIs, 18–92 years). In additional analyses, we tested coherence with cell-specific gene expression maps from the Allen Human Brain Atlas, and relations to changes in memory performance. “PSQI # 1 Subjective sleep quality” and “PSQI #5 Sleep disturbances” were related to thinning of the right lateral temporal cortex, with lower quality and more disturbances being associated with faster thinning. The association with “PSQI #5 Sleep disturbances” emerged after 60 years, especially in regions with high expression of genes related to oligodendrocytes and S1 pyramidal neurons. None of the sleep scales were related to a longitudinal change in episodic memory function, suggesting that sleep-related cortical changes were independent of cognitive decline. The relationship to cortical brain change suggests that self-reported sleep parameters are relevant in lifespan studies, but small effect sizes indicate that self-reported sleep is not a good biomarker of general cortical degeneration in healthy older adults.

Human Brain Resilience: A Call to Action

“…For example, there is abundant epidemiological evidence that adherence to certain lifestyle factors, including cognitive, physical, nutritional, and sleep healthy habits can exert a positive effect on both objective (eg, cognitive performance) and subjective (eg, sense well‐being) status. In addition, a growing literature reveals the positive influence of many of these same lifestyle factors, as well as the engagement of individuals in emotion‐regulation practices, such as meditation on brain structure and functional measures 73–76 . Consequently, the effort toward an individual index of resilience needs to incorporate information about lifestyle, the psychological status of individuals, as well as an evaluation of general health risk factors (eg, smoking, being overweight, or having abnormal states of hypertension, cholesterol or fasting glucose, see the American Heart Association, American Stroke Association recommendations) 77 …”

“…In addition, a growing literature reveals the positive influence of many of these same lifestyle factors, as well as the engagement of individuals in emotion-regulation practices, such as meditation on brain structure and functional measures. [73][74][75][76] Consequently, the effort toward an individual index of resilience needs to incorporate information about lifestyle, the psychological status of individuals, as well as an evaluation of general health risk factors (eg, smoking, being overweight, or having abnormal states of hypertension, cholesterol or fasting glucose, see the American Heart Association, American Stroke Association recommendations). 77 In fact, we believe that such a "Lifestyle Medicine" approach needs to be expanded to consider the individual in a more holistic manner.…”

Sleep duration and brain structure – phenotypic associations and genotypic covariance

“…The models provided the best fits taking both cross-sectional and longitudinal observations into account. We have previously reported on change relationships specifically 50 . 11 subcortical regions, four segments of the corpus callosum (CC), total ventricular volume and total gray matter volume, which is the sum of cortical, subcortical and cerebellar gray matter, were included.…”

“…ICV was tested in a separate analysis and was additionally included as covariate of no interest in all volumetric analyses. The cortical analyses were focused on thickness, which changes considerably with age [50][51][52] . 32 cortical regions from the Desikan-Killiany parcellation scheme 53 were included, visualized using ggseg 54 .…”

The genetic organization of longitudinal subcortical volumetric change is stable throughout the lifespan

“…Participants were screened to be cognitively healthy and in general not suffer from conditions known to affect brain function, such as dementia, major stroke, multiple sclerosis, etc. Exact screening criteria were not identical across sub-samples (see Fjell et al, 2021 for details).…”