The effect of occupation on the incidence of vascular dementia: A 12-year follow-up cohort study.

INTRODUCTION: Vascular dementia (DV) is the second cause of dementia with 15.8-20% of cases. Previous studies of the effect of occupation in DV do not show conclusive results, therefore, the objective was to analyze if the type of occupation can vary the risk of developing DV in those older than 55 years. MATERIAL AND METHODS: In the ZARADEMP project, a community sample of 4,803 individuals were followed longitudinally in four waves. The occupation was classified following the National Classification of Occupations (CNO-11) and the International Standard Classification of Occupations (ISCO-08). Different standardized instruments were used: the medical and psychiatric histories (History and Aetiology Schedule) and other risk factors (Mini-Mental Status Examination, Geriatric Mental State-AGECAT). For this study, we calculated incidence rates, incidence rate ratios and hazard ratios in multivariate Cox regression models, stratified by gender. For this study, we included 3,883 participants. RESULTS: In women, the risk of DV was doubled in Blue-collar workers, with a moderate effect (Cohen's d=0.54) and multiplying by 2.7 in Homeworks respect to White Collar with a moderate effect (Cohen's d=0.77), although they did not reach statistical significance. We did not observe the effect of occupation on the risk of DV in men. CONCLUSIONS: We have found a moderate but non-significant effect between occupation and DV risk in women. We found no effect of occupation on the risk of VD in males while other clinical factors (age, diabetes or body mass index) presented a clearer effect than the occupation.

The effect of occupation on the incidence of vascular dementia: A 12-year follow-up cohort study. / El efecto de la ocupación laboral en la incidencia de demencia vascular: un estudio de cohortes de 12 años de seguimiento.

INTRODUCTION: Vascular dementia (DV) is the second cause of dementia with 15.8-20% of cases. Previous studies of the effect of occupation in DV do not show conclusive results, therefore, the objective was to analyze if the type of occupation can vary the risk of developing DV in those older than 55 years. MATERIAL AND METHODS: In the ZARADEMP project, a community sample of 4,803 individuals were followed longitudinally in 4 waves. The occupation was classified following the National Classification of Occupations of 2011 and the International Standard Classification of Occupations of 2008. Different standardized instruments were used: the medical and psychiatric histories (History and Aetiology Schedule) and other risk factors (Mini-Mental Status Examination, Geriatric Mental State-AGECAT). For this study, we calculated incidence rates, incidence rate ratios and hazard ratios in multivariate Cox regression models, stratified by gender. For this study, we included 3,883 participants. RESULTS: In women, the risk of DV was doubled in blue-collar workers, with a moderate effect (Cohen's d=0.54), and multiplying by 2.7 in homeworks respect to white-collar with a moderate effect (Cohen's d=0.77), although they did not reach statistical significance. We did not observe the effect of occupation on the risk of DV in men. CONCLUSIONS: We have found a moderate but non-significant effect between occupation and DV risk in women. We found no effect of occupation on the risk of VD in males while other clinical factors (age, diabetes or body mass index) presented a clearer effect than the occupation.

The effect of occupation type on risk of Alzheimer's disease in men and women.

OBJECTIVES: To examine the association between the principal lifetime occupation and the incidence of Alzheimer's disease (AD) in men and women in a southern European population aged 55 years or more. STUDY DESIGN: A community-dwelling sample of 3883 dementia-free individuals aged 55 years or over was classified according the Spanish National Classification of Occupations (CNO-11) and the International Standard Classification of Occupations (ISCO-08) in a four-wave epidemiological study. Medical and psychiatric histories were collected using standardized instruments, including the Mini-Mental Status Examination (MMSE), the History and Aetiology Schedule (HAS), the Geriatric Mental State-AGECAT, and a risk factor Questionnaire. Cases of AD were diagnosed according to DSM-IV criteria. Cox regression models were performed, stratified by sex. MAIN OUTCOME MEASURES: Cases of AD according to the main occupation and sex. RESULTS: In men, compared with the "white collar" category, the risk of AD in "farmers" was 66% times lower, after controlling for potential confounding factors (HR: 0.34; 95% CI: 0.08-1.33). It did not reach statistical significance but the magnitude was large (Cohen's d = 0.84). In women, "farmers" had almost 50% less risk of AD after controlling for all potential confounding factors (HR: 0.55; 95% CI: 0.17-1.78), compared with homemakers, but with a medium effect size (Cohen's d = 0.46). CONCLUSIONS: Men and women farmers had a lower risk of AD, reinforcing the importance of lifetime occupation in the risk of AD at older ages. These results could suggest some environmental hypotheses.

[Influence of occupation on cognitive impairment with no dementia in a sample population over 55 years from Zaragoza]. / Influencia de la ocupación en el deterioro cognitivo libre de demencia en una muestra de sujetos mayores de 55 años de Zaragoza.

INTRODUCTION: The prevalence of cognitive impairment with no dementia (CIND) varies between 5.1% and 35.9%, increasing between 65 and 85 years. The CIND increases the risk of dementia. Factors such as education, occupation, and social activities are associated with the risk of cognitive impairment. The main objective of this study was to analyse the association between the main occupation developed throughout life and CIND in a general population sample of over 55 years. METHODS: In wave I of the ZARADEMP Project, a sample (n=4803) of people over 55 years was interviewed. CIND measurement was obtained through the Mini Mental State Examination. Occupational activity data were recoded into white collar, blue collar, homemakers, and farmers. The association between the occupation variables and CIND was estimated using the odds ratio, and 95% confidence intervals using logistic regression equations. RESULTS: The prevalence of CIND in the sample was 28.2%. As regards white collar workers, the CIND diagnosis odds was 53% higher for blue collar workers, 77% higher for women who were homemakers and almost twice for farmers, after controlling for socio-demographic, behavioural and clinical variables. All results were statistically significant. CONCLUSIONS: CIND frequency is influenced by the previous occupation of the subjects. An occupation with higher intellectual requirements can help keep cognitive functions intact for longer.

[Occupation and Risk of Cognitive Impairment and Dementia in People in over 55 Years: A Systematic Review, Spain]. / Ocupación laboral y riesgo de deterioro cognitivo y demencia en personas mayores de 55 años: una revisión sistemática.

BACKGROUND: Cognitive impairment and dementia are two problems with high prevalence in the elderly population. It is important to identify potentially modifiable risk factors that are associated with them. The occupation developed throughout life could be a risk factor in dementia. The objective was to analyze the association between the principal occupation developed along life and cognitive impairment or dementia in old people. METHODS: A systematic review of scientific publications dated between 1990 and March 2014 to find studies analyzing the relationship between occupation and cognitive impairment assessed by the Mini-Mental Status Examination (MMSE). Databases such as ISI Web of Knowledge, PubMed and others, were reviewed. Criteria for inclusion: articles published between 1990 and March 2014, using the MMSE to assess cognitive performance, population over 55 years old, including occupation as study variable as well as cognitive impairment or dementia, written in Spanish, English or French. RESULTS: 18 articles were selected to review. Five cross-sectional and six longitudinal studies analyzed the association between occupation and cognitive impairment; two cross-sectional and eight longitudinal studies analyzed the association between dementia and occupation. 67% identified a relationship between the type of work and cognitive performance in adulthood. CONCLUSIONS: Those who have a predominantly manual occupation throughout life, have an increased risk of cognitive impairment and/or dementia than those with occupations with higher intellectual requirement.

OBJETIVO: El deterioro cognitivo y la demencia son dos problemas de salud con elevada prevalencia en población mayor. Es importante identificar los factores de riesgo potencialmente modificables asociados. La ocupación laboral podría ser un factor que influye en la demencia. El objetivo fue analizar la asociación entre la ocupación principal desarrollada a lo largo de la vida con el deterioro cognitivo y la demencia en personas mayores. METODOS: Revisión sistemática de la literatura desde 1990 y marzo de 2014 para identificar la asociación entre ocupación y deterioro cognitivo evaluado por el Mini Mental Status Examination (MMSE). La búsqueda se realizó en las bases de datos Web of Knowledge, Pubmed, Medline, ISI Web of Science, Science Direct, CocINDEX with Full Text, SPORTDiscus with Full Text, Dialnet Plus, Education Resources Information Center, GreenFile, Journal Storage y The Cochrane Library. Criterios de inclusión: artículos publicados entre 1990 y marzo de 2014 que utilizaran el MMSE para valorar el rendimiento cognitivo en población mayor de 55 años y que incluyeran la ocupación como variable de estudio así como la existencia de deterioro cognitivo o demencia, escritos en castellano, inglés o francés. RESULTADOS: Se seleccionaron 18 artículos. Cinco estudios transversales y seis longitudinales analizaron la asociación entre ocupación y deterioro cognitivo; dos transversales y ocho longitudinales estudiaron la asociación entre demencia y ocupación. El 67% identificaron que había relación entre el tipo de trabajo y el rendimiento cognitivo en la edad adulta. CONCLUSIONES: Las personas con una actividad laboral predominantemente manual a lo largo de la vida tienen mayor riesgo de padecer deterioro cognitivo y/o demencia que aquellas que tienen ocupaciones con mayor requerimiento intelectual.