Forskningsartikler

Abstract

Background:
Childlessness, as well as having a high number of children, has been reported to be associated with an elevated risk of dementia compared to having 2–3 children. The mechanisms underlying these relationships are not well understood and may be mediated by different midlife risk factors. We examined the mediating role of various factors on the relationship between the number of children and dementia risk. These factors include socioeconomic factors (e.g., occupational complexity), psychosocial (e.g.., social activities, loneliness, life satisfaction), lifestyle (e.g., smoking, physical inactivity, alcohol intake), and chronic diseases (e.g., obesity, diabetes, depression, hearing impairment and hypertension).

Methods:
Using a historic cohort design, we included 9,745 participants born between 1931–48, with a mean age of 78.2 (SD = 6.4) years at the time of cognitive testing in the HUNT4 70 + sub-study (2017–2019). Further measures were obtained through data linkage between information from Statistics Norway and the HUNT1(1984–86), and HUNT2 (1995–97) Surveys. Causal mediation analyses using an inverse odd weighting approach were conducted to decompose the total effect of the number of children (0, 1, or 4 + children vs. 2–3) on the risk of dementia at age 70 + years into direct and indirect effects with mediators assessed at a mean age of 50.7 (SD = 6.4) years. The analyses were adjusted for age, sex, marital status at age 25 years, educational status, and religion assessed during HUNT3 (2006–2008).

Results:
Overall, 15.7% were diagnosed with dementia. The proportions with dementia by the number of children were 22.3% among those with no children, 21.4% for those with one child, 13% for those with 2–3 children (specifically, 12.6% for those with 2 children and 13.4% for those with 3 children), and 19.9% for those with 4 + children. Compared to the reference group of individuals with 2–3 children, the dementia risk was higher among the groups with no children (relative risk (RR): 1.30, 95% confidence interval (CI) (1.12, 1.51)), those with one child (RR: 1.30, 95% CI (1.14, 1.47)) and those with 4 + children (RR: 1.12, 95% CI (1.01, 1.24)). The elevated risks of dementia were not mediated by the socioeconomic, psychosocial, lifestyle, or chronic diseases related factors that we tested. Sex-stratified analysis showed higher dementia risk for men without children and women with one or 4 + children compared to those with 2–3 children, with similar patterns across sexes. None of the mediators contributed to mediation in either group. None of the mediators appeared to contribute through mediation in either group.

Conclusions:
Our findings suggest that the number of children—specifically being childless, having one child, or having four or more children—may influence the risk of dementia. These relationships were not mediated by psychosocial, lifestyle, and socioeconomic factors, or markers of chronic diseases in adulthood considered in this study.

Teferi Mekonnen, Vegard Skirbekk, Ekaterina Zotcheva, Bo Engdahl, Bernt Bratsberg, Astanand Jugessur, Catherine Bowen, Geir Selbæk, Hans-Peter Kohler, Jennifer R. Harris, Sarah E. Tom, Steinar Krokstad, Trine Holt Edwin, Yehani Wedatilake, Katrin Wolfova, Dana Kristjansson, Yaakov Stern, Asta Kristine Håberg & Bjørn Heine Strand

Introduction:
Hearing impairment is associated with dementia. We aimed to clarify the association between hearing impairment and future cognitive test performance measured by the Montreal Cognitive Assessment Scale (MoCA), adjusted for confounders, avoiding reverse causation through long follow-up.

Methods:
We used the Norwegian population-based longitudinal cohort study, The Trøndelag Health Study (HUNT). At baseline, we invited all residents 20+ for an audiometric hearing assessment, and at 20+ years follow-up, we cognitively assessed all persons 70+ including MoCA adjusted for hearing impairment. We analyzed the association using linear regression.
Results:
We included 6879 persons (mean 56.1 years, standard deviation 6.2). At follow-up, the MoCA score was −0.25 (95% confidence interval [CI] −0.35, −0.14), per 10 dB increase in hearing threshold and for persons < 85 years, −0.31 (95% CI −0.42, −0.20).
Discussion:
This study finds a long-term association between hearing impairment and dose related reduced cognitive performance, particularly in those aged < 85.

Christian Myrstad, Bo Lars Engdahl, Sergi Gonzalez Costafreda, Steinar Krokstad, Gill Livingston, Geir Selbæk

Background: Spatial orientation is required for independent mobility in society. Deficits in spatial orientation can be an early symptom of Alzheimer’s disease and other dementias, and there is a need for brief assessment tools to identify impairments.

Objective: The aim of this study was to evaluate the construct and known-group validity of our newly developed Spatial Orientation Screening (SOS) questionnaire.

Methods: We included 132 patients with subjective cognitive decline (n = 16), mild cognitive impairment (n = 32), or all-cause dementia (n = 84) from a memory clinic and a reference group of cognitively unimpaired older adults (n = 108). The patients and their next-of-kin answered the self- and proxy-rated versions of the 4-item SOS (0-8 points) and the 10-item Questionnaire of Everyday Navigational Ability (QuENA, 0-30 points). The patients also performed the Floor Maze Test (FMT) for performance-based spatial abilities.

Results: Mean ages (SD) of the patient and reference groups were 68.6 (±7.6) years and 73.7 (±6.7) years, respectively. Construct validity between self-rated versions of the SOS and QuENA was satisfactory with rs = 0.66, between the proxy-rated versions rs = 0.61, and between the proxy-reported SOS and FMT rs = 0.49 (all p < 0.001). Known-group validity was also acceptable, with significantly higher median (IQR) SOS self-reported scores in patients 1.0 (2.0) compared to the reference group 0.2 (0.5) points, (p < 0.001). Informants reported more severe impairments compared to the patients’ self-reports on both SOS and QuENA (both p < 0.001).

Conclusions: The SOS had satisfactory validity for use as a screening instrument for assessment of spatial orientation in memory clinic patients.

Gro Gujord Tangen, Knut Engedal, Karin Persson, Geir Selbæk, Shams Dakhil, Riona McArdle, Marit Mjørud, Janne Røsvik, Anne Marit Mengshoel, Anne Brita Knapskog

Introduction
Informal care estimates for use in health-economic models are lacking. We aimed to estimate the association between informal care time and dementia symptoms across Europe.
Methods
A secondary analysis was performed on 13,529 observations in 5,369 persons from 9 European pooled cohort or trial studies in community-dwelling persons with dementia. A mixed regression model was fitted to time spent on instrumental or basic activities of daily living using disease severity and demographic characteristics.
Results
Daily informal care time was 0.5 hours higher in moderate compared to mild and 1.3h higher in severe compared to mild cognitive impairment. Likewise, this was 1.2h and 2.7h for functional disability and 0.3h and 0.6h for behavioral symptoms in the same directions.
Discussion
Estimates can be used in both single- and multi-domain health-economic models for dementia in European settings.

Ron Handels, Somboon Hataiyusuk, Anders Wimo, Anders Sköldunger, Christian Bakker, Anja Bieber, Alfonso Ciccone, Carlo Alberto Defanti, Andrea Fabbo, Sara Fascendini, Lutz Frölich, Chloé Gervès-Pinquié, Manuel Gonçalves-Pereira, Kate Irving, Raymond Koopmans, Patrizia Mecocci, Paola Merlo, Bernhard Michalowsky, Oliver Peters, Yolande Pijnenburg, Óscar Ribeiro, Geir Salbaek, Larissa Schwarzkopf, Hilde Verbeek, Marjolein de Vugt, Bob Woods, Orazio Zanetti, Bengt Winblad, Linus Jönsson; Actifcare consortium, ICTUS/DSA group, PLASA/DSA group, RECAGE consortium, RightTimePlaceCare consortium