- •Education reduced the dementia death risk when follow-up started in adulthood.
- •This protective effect was robust to adjustment.
- •Education had no protective effect when follow-up started in old age.
- •This could imply that education delays onset, but not the late phases of dementia.
An inverse relationship between educational level and dementia has been reported in several studies. In this study we investigated the relationship between educational level and dementia related deaths for cohorts of people all born during 1915–39. The cohorts were followed up from adulthood or old age, taking into account possible confounders and mediating paths. Our study population comprised participants in Norwegian health examination studies in the period 1974–2002; The Counties Study and Cohort of Norway (CONOR). Dementia related deaths were defined as deaths with a dementia diagnosis on the death certificate and linked using the Cause of Death Registry to year 2012. The study included 90,843 participants, 2.06 million person years and 2440 dementia related deaths. Cox regression was used to assess the association between education and dementia related deaths. Both high and middle educational levels were associated with lower dementia related death risk compared to those with low education when follow-up started in adulthood (35–49 years, high versus low education: HR = 0.68, 95% confidence interval (CI) 0.50–0.93; 50–69 years, high versus low education: HR = 0.52, 95% CI 0.34–0.80). However, when follow-up started at old age (70–80 years) there was no significant association between education and dementia related death. Restricting the study population to those born during a five-year period 1925–29 (the birth cohort overlapping all three age groups), gave similar main findings. The protective effects found for both high and middle educational level compared to low education were robust to adjustment for cardiovascular health and life style factors, suggesting education to be a protective factor for dementia related death. Both high and middle educational levels were associated with decreased dementia related death risk compared with low educational level when follow-up started in adulthood, but no association was observed when follow-up started at old age.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of the Neurological Sciences
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Education and the prevalence of dementia and Alzheimer's disease.Neurology. 1993; 43: 13-20
- Education and other socioeconomic determinants of dementia and Alzheimer's disease.. 1993; 43: S39-S44
- Education and Alzheimer's disease: a review of recent international epidemiological studies.Aging Ment Health. 1997; 1: 33-46
- Brain reserve hypothesis in dementia.J Alzheimers Dis. 2007; 12: 11-22
- Systematic review of the effect of education on survival in Alzheimer's disease.Int Psychogeriatr. 2009; 21: 25-32
- Education and dementia: a meta-analytic study.Neuroepidemiology. 2006; 26: 226-232
- Brain reserve and cognitive decline: a non-parametric systematic review.Psychol Med. 2006; 36: 1065-1073
- Education and dementia in the context of the cognitive reserve hypothesis: a systematic review with meta-analyses and qualitative analyses.PLoS One. 2012; 7: e38268
- Relationship between education and dementia: an updated systematic review.Alzheimer Dis Assoc Disord. 2011; 25: 289-304
- Cognitive reserve.Neuropsychologia. 2009; 47: 2015-2028
- Pathological markers associated with normal aging and dementia in the elderly.Ann Neurol. 1993; 34: 566-573
- Alzheimer neuropathologic alterations in aged cognitively normal subjects.J Neuropathol Exp Neurol. 1999; 58: 376-388
- Alzheimer's neurofibrillary pathology and the spectrum of cognitive function: findings from the Nun Study.Ann Neurol. 2002; 51: 567-577
- What is cognitive reserve? Theory and research application of the reserve concept.J Int Neuropsychol Soc. 2002; 8: 448-460
- Cognitive reserve in ageing and Alzheimer's disease.Lancet Neurol. 2012; 11: 1006-1012
- Cognitive reserve in aging.Curr Alzheimer Res. 2011; 8: 354-360
- Lifetime antecedents of cognitive reserve.J Clin Exp Neuropsychol. 2003; 25: 614-624
- Cognitive activities delay onset of memory decline in persons who develop dementia.Neurology. 2009; 73: 356-361
- Video game training enhances cognitive control in older adults.Nature. 2013; 501: 97-101
- An active and socially integrated lifestyle in late life might protect against dementia.Lancet Neurol. 2004; 3: 343-353
- Education associated with a delayed onset of terminal decline.Age Ageing. 2014; 43: 26-31
- Cognitive activity, education and socioeconomic status as preventive factors for mild cognitive impairment and Alzheimer's disease.Psychiatry Res. 2012; 196: 90-95
- Increased risk of mortality in Alzheimer's disease patients with more advanced educational and occupational attainment.Ann Neurol. 1995; 37: 590-595
- The influence of education on clinically diagnosed dementia incidence and mortality data from the Kungsholmen Project.Arch Neurol. 2001; 58: 2034-2039
- The cardiovascular disease study in Norwegian counties.Oslo, Norway, The National Mass Radiography Service1983
- Cohort profile: cohort of Norway (CONOR).Int J Epidemiol. 2008; 37: 481-485
- What is high blood pressure?.NIH, USA2014 ([[cited 2014 14.01]. Available from: http://www.nhlbi.nih.gov/health/health-topics/topics/hbp/])
- What is hypotension?.NIH, USA2014 ([[cited 2014 14.01]. Available from: http://www.nhlbi.nih.gov/health/health-topics/topics/hyp/])
- A comparison of the CONOR Mental Health Index to the HSCL-10 and HADS. Measuring mental health status in The Oslo Health Study and the Nord-Trøndelag Health Study.Nor J Epidemiol. 2003; 13: 6
- Education policy and the heritability of educational attainment.Nature. 1985; 314: 734-736
- Can cardiovascular risk factors and lifestyle explain the educational inequalities in mortality from ischaemic heart disease and from other heart diseases? 26 year follow up of 50,000 Norwegian men and women.J Epidemiol Community Health. 2004; 58: 705-709
- Midlife vascular risk factors and their association with dementia deaths: results from a Norwegian prospective study followed up for 35 years.J Neurol Sci. 2013; 324: 124-130
- Cognitive reserve: implications for assessment and intervention.Folia Phoniatr Logop. 2013; 65: 49-54
- Trends in the prevalence and mortality of cognitive impairment in the United States: is there evidence of a compression of cognitive morbidity?.Alzheimers Dement. 2008; 4: 134-144
- Validation of Norwegian death certificates on dementia in residents of nursing homes.Epidemiology. 1998; 9: 584-586
- Dementia in the National Cause of Death Registry in Norway 1969–2010.Nor J Epidemiol. 2012; 22: 8
Published online: July 09, 2014
Accepted: July 3, 2014
Received in revised form: June 24, 2014
Received: February 17, 2014
© 2014 Elsevier B.V. Published by Elsevier Inc. All rights reserved.