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Cited by 29Sleep and Wakefulness ResearchSleep and related disordersGenetic Associations and Epidemiology

Is there an association between daytime napping, cognitive function, and brain volume? A Mendelian randomization study in the UK Biobank

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Paz, Valentina, Dashti, Hassan S., Garfield, Victoria·2023·Sleep Health
DOI 10.1016/j.sleh.2023.05.002PMC PMC13344058
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Abstract

OBJECTIVES: Daytime napping has been associated with cognitive function and brain health in observational studies. However, it remains elusive whether these associations are causal. Using Mendelian randomization, we studied the relationship between habitual daytime napping and cognition and brain structure. METHODS: Data were from UK Biobank (maximum n = 378,932 and mean age = 57 years). Our exposure (daytime napping) was instrumented using 92 previously identified genome-wide, independent genetic variants (single-nucleotide polymorphisms, SNPs). Our outcomes were total brain volume, hippocampal volume, reaction time, and visual memory. Inverse-variance weighted was implemented, with sensitivity analyses (Mendelian randomization-Egger and Weighted Median Estimator) for horizontal pleiotropy. We tested different daytime napping instruments to ensure the robustness of our results. RESULTS: and 95% CI = -0.13;0.06), reaction time (expß = 1.01 and 95% CI = 1.00;1.03), or visual memory (expß = 0.99 and 95% CI = 0.94;1.05). Additional analyses with 47 SNPs (adjusted for excessive daytime sleepiness), 86 SNPs (excluding sleep apnea), and 17 SNPs (no sample overlap with UK Biobank) were largely consistent with our main findings. No evidence of horizontal pleiotropy was found. CONCLUSIONS: Our findings suggest a modest causal association between habitual daytime napping and larger total brain volume. Future studies could focus on the associations between napping and other cognitive or brain outcomes and replication of these findings using other datasets and methods.

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  • A UKB MR study found a small association between habitual napping and higher brain volume (unstandardized ß 15.80 cm3, 0.25-31.34) but no difference in hippocampal volume or cognitive tests.

    “A UKB MR study found a small association between habitual napping and higher brain volume (unstandardized ß 15.80 cm 3 , 0.25- 31.34) but no difference in hippocampal volume or cognitive tests.(307)”

    From Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission (2024) · cites this paper as [307]

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Cited by

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Authors
Paz, V., Dashti, H. S., & Garfield, V.
Affiliations
  • Universidad de la República de Uruguay (UY)
  • Broad Institute (US)
  • MRC Unit for Lifelong Health and Ageing (GB)
Corresponding author
Paz, Valentina
ORCID
Venue
Sleep Health
Publisher
Elsevier BV
Published
2023-10
Volume
9
Issue
5
Pages
786-793
ISSN
2352-7218 (ISSN-L)
DOI
10.1016/j.sleh.2023.05.002
PMC
PMC13344058
OpenAlex
W4381249673
Cited by
29
References
1
Citations by year
2026: 9 · 2025: 6 · 2024: 9 · 2023: 5
FWCI
4.34
Type
journal article
Language
en
Open access
Licence
Locations
  • Sleep Health (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • UCL Discovery (University College London) (submittedVersion, cc-by)
  • PubMed Central (submittedVersion)
Funders
  • Diabetes Research and Wellness Foundation (SCA/01/NCF/22)
  • Universidad de la República Uruguay
  • National Heart Lung and Blood Institute (K99HL153795)
  • Agencia Nacional de Investigación e Innovación (MOV_CA_2020_1_163153)
  • British Heart Foundation (SP/16/6/32726)
  • Programa de Desarrollo de las Ciencias Básicas
  • Comisión Sectorial de Investigación Científica
  • Diabetes UK (15/0005250 - VG)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic Associations and Epidemiology
Keywords
daytime napping, cognitive function, total brain volume, hippocampal volume, reaction time, visual memory, causal inference, genetic variants

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