TY - JOUR
T1 - Hospital-diagnosed sleep disorders and incident dementia
T2 - a nationwide observational cohort study
AU - Damsgaard, Line
AU - Janbek, Janet
AU - Laursen, Thomas Munk
AU - Erlangsen, Annette
AU - Spira, Adam P.
AU - Waldemar, Gunhild
N1 - Publisher Copyright:
© 2022 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.
PY - 2022
Y1 - 2022
N2 - Background and purpose: Several smaller, community-based studies have suggested a link between sleep disorders and dementia with a focus on sleep as a modifiable risk factor for dementia. Studies on neurodegenerative diseases are prone to reverse causation, and few studies have examined the association with long follow-up time. Our aim was to explore the possible association between sleep disorders and late-onset dementia in an entire population. Methods: In a nationwide cohort with 40-year follow-up, associations between hospital-based sleep disorder diagnoses and late-onset dementia were assessed. Incidence rate ratios (IRR) were calculated using Poisson regression. Results: The cohort consisted of 1,491,276 people. Those with any sleep disorder had a 17% higher risk of dementia (IRR 1.17, 95% confidence interval [CI] 1.11–1.24) compared to people with no sleep disorder, adjusted for age, sex, calendar year, highest attained educational level at age 50, and somatic and psychiatric comorbidity. The risk of dementia was significantly increased 0–5 years after sleep disorder diagnosis (IRR 1.35, 95% CI 1.25–1.47), whilst the association after 5 years or more was non-significant (1.05, 95% CI 0.97–1.13). Conclusions: Our findings show an increased short-term risk of dementia following a hospital-based sleep disorder diagnosis, whilst weaker evidence of a long-term risk was found. This could potentially point towards sleep disorders as an early symptom of dementia. Further research is needed to distinguish sleep disorders as an early symptom of dementia, a risk factor, or both.
AB - Background and purpose: Several smaller, community-based studies have suggested a link between sleep disorders and dementia with a focus on sleep as a modifiable risk factor for dementia. Studies on neurodegenerative diseases are prone to reverse causation, and few studies have examined the association with long follow-up time. Our aim was to explore the possible association between sleep disorders and late-onset dementia in an entire population. Methods: In a nationwide cohort with 40-year follow-up, associations between hospital-based sleep disorder diagnoses and late-onset dementia were assessed. Incidence rate ratios (IRR) were calculated using Poisson regression. Results: The cohort consisted of 1,491,276 people. Those with any sleep disorder had a 17% higher risk of dementia (IRR 1.17, 95% confidence interval [CI] 1.11–1.24) compared to people with no sleep disorder, adjusted for age, sex, calendar year, highest attained educational level at age 50, and somatic and psychiatric comorbidity. The risk of dementia was significantly increased 0–5 years after sleep disorder diagnosis (IRR 1.35, 95% CI 1.25–1.47), whilst the association after 5 years or more was non-significant (1.05, 95% CI 0.97–1.13). Conclusions: Our findings show an increased short-term risk of dementia following a hospital-based sleep disorder diagnosis, whilst weaker evidence of a long-term risk was found. This could potentially point towards sleep disorders as an early symptom of dementia. Further research is needed to distinguish sleep disorders as an early symptom of dementia, a risk factor, or both.
KW - dementia
KW - epidemiology
KW - risk factors
KW - sleep apnea syndromes
KW - sleep–wake disorders
U2 - 10.1111/ene.15517
DO - 10.1111/ene.15517
M3 - Journal article
C2 - 35916072
AN - SCOPUS:85137000570
VL - 29
SP - 3528
EP - 3536
JO - European Journal of Neurology
JF - European Journal of Neurology
SN - 1351-5101
IS - 12
ER -