Browsing by Author "Köhler S"

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    Determinants of cognitive performance and decline in 20 diverse ethno-regional groups: A COSMIC collaboration cohort study
    (Public Library of Science (PLoS), 2019-07) Lipnicki DM; Makkar SR; Crawford JD; Thalamuthu A; Kochan NA; Lima-Costa MF; Castro-Costa E; Ferri CP; Brayne C; Stephan B; Llibre-Rodriguez JJ; Llibre-Guerra JJ; Valhuerdi-Cepero AJ; Lipton RB; Katz MJ; Derby CA; Ritchie K; Ancelin M-L; Carrière I; Scarmeas N; Yannakoulia M; Hadjigeorgiou GM; Lam L; Chan W-C; Fung A; Guaita A; Vaccaro R; Davin A; Kim KW; Han JW; Suh SW; Riedel-Heller SG; Roehr S; Pabst A; van Boxtel M; Köhler S; Deckers K; Ganguli M; Jacobsen EP; Hughes TF; Anstey KJ; Cherbuin N; Haan MN; Aiello AE; Dang K; Kumagai S; Chen T; Narazaki K; Ng TP; Gao Q; Nyunt MSZ; Scazufca M; Brodaty H; Numbers K; Trollor JN; Meguro K; Yamaguchi S; Ishii H; Lobo A; Lopez-Anton R; Santabárbara J; Leung Y; Lo JW; Popovic G; Sachdev PS; for Cohort Studies of Memory in an International Consortium (COSMIC)
    Background With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups. Methods and findings We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54–105 (mean = 72.7) years and without dementia at baseline. Studies had 2–15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = −0.1, SE = 0.01), APOE*4 carriage (B = −0.31, SE = 0.11), depression (B = −0.11, SE = 0.06), diabetes (B = −0.23, SE = 0.10), current smoking (B = −0.20, SE = 0.08), and history of stroke (B = −0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = −0.07, SE = 0.01), APOE*4 carriage (B = −0.41, SE = 0.18), and diabetes (B = −0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = −0.24, SE = 0.12), and between diabetes and cognitive decline (B = −0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife. Conclusions These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.
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    Does parity matter in women’s risk of dementia? A COSMIC collaboration cohort study
    (BMC, 2020-08-05) Bae JB; Lipnicki DM; Han JW; Sachdev PS; Kim TH; Kwak KP; Kim BJ; Kim SG; Kim JL; Moon SW; Park JH; Ryu S-H; Youn JC; Lee DY; Lee DW; Lee SB; Lee JJ; Jhoo JH; Llibre-Rodriguez JJ; Llibre-Guerra JJ; Valhuerdi-Cepero AJ; Ritchie K; Ancelin M-L; Carriere I; Skoog I; Najar J; Sterner TR; Scarmeas N; Yannakoulia M; Dardiotis E; Meguro K; Kasai M; Nakamura K; Riedel-Heller S; Roehr S; Pabst A; van Boxtel M; Köhler S; Ding D; Zhao Q; Liang X; Scazufca M; Lobo A; De-la-Cámara C; Lobo E; Kim KW; for Cohort Studies of Memory in an International Consortium (COSMIC)
    Background Dementia shows sex difference in its epidemiology. Childbirth, a distinctive experience of women, is associated with the risk for various diseases. However, its association with the risk of dementia in women has rarely been studied. Methods We harmonized and pooled baseline data from 11 population-based cohorts from 11 countries over 3 continents, including 14,792 women aged 60 years or older. We investigated the association between parity and the risk of dementia using logistic regression models that adjusted for age, educational level, hypertension, diabetes mellitus, and cohort, with additional analyses by region and dementia subtype. Results Across all cohorts, grand multiparous (5 or more childbirths) women had a 47% greater risk of dementia than primiparous (1 childbirth) women (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.10–1.94), while nulliparous (no childbirth) women and women with 2 to 4 childbirths showed a comparable dementia risk to primiparous women. However, there were differences associated with region and dementia subtype. Compared to women with 1 to 4 childbirths, grand multiparous women showed a higher risk of dementia in Europe (OR = 2.99, 95% CI = 1.38–6.47) and Latin America (OR = 1.49, 95% CI = 1.04–2.12), while nulliparous women showed a higher dementia risk in Asia (OR = 2.15, 95% CI = 1.33–3.47). Grand multiparity was associated with 6.9-fold higher risk of vascular dementia in Europe (OR = 6.86, 95% CI = 1.81–26.08), whereas nulliparity was associated with a higher risk of Alzheimer disease (OR = 1.91, 95% CI 1.07–3.39) and non-Alzheimer non-vascular dementia (OR = 3.47, 95% CI = 1.44–8.35) in Asia. Conclusion Parity is associated with women’s risk of dementia, though this is not uniform across regions and dementia subtypes.
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    Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study
    (BioMed Central Ltd, 2020-12-18) Röhr S; Pabst A; Riedel-Heller SG; Jessen F; Turana Y; Handajani YS; Brayne C; Matthews FE; Stephan BCM; Lipton RB; Katz MJ; Wang C; Guerchet M; Preux P-M; Mbelesso P; Ritchie K; Ancelin M-L; Carrière I; Guaita A; Davin A; Vaccaro R; Kim KW; Han JW; Suh SW; Shahar S; Din NC; Vanoh D; van Boxtel M; Köhler S; Ganguli M; Jacobsen EP; Snitz BE; Anstey KJ; Cherbuin N; Kumagai S; Chen S; Narazaki K; Ng TP; Gao Q; Gwee X; Brodaty H; Kochan NA; Trollor J; Lobo A; López-Antón R; Santabárbara J; Crawford JD; Lipnicki DM; Sachdev PS; for Cohort Studies of Memory in an International Consortium (COSMIC)
    Background Subjective cognitive decline (SCD) is recognized as a risk stage for Alzheimer’s disease (AD) and other dementias, but its prevalence is not well known. We aimed to use uniform criteria to better estimate SCD prevalence across international cohorts. Methods We combined individual participant data for 16 cohorts from 15 countries (members of the COSMIC consortium) and used qualitative and quantitative (Item Response Theory/IRT) harmonization techniques to estimate SCD prevalence. Results The sample comprised 39,387 cognitively unimpaired individuals above age 60. The prevalence of SCD across studies was around one quarter with both qualitative harmonization/QH (23.8%, 95%CI = 23.3–24.4%) and IRT (25.6%, 95%CI = 25.1–26.1%); however, prevalence estimates varied largely between studies (QH 6.1%, 95%CI = 5.1–7.0%, to 52.7%, 95%CI = 47.4–58.0%; IRT: 7.8%, 95%CI = 6.8–8.9%, to 52.7%, 95%CI = 47.4–58.0%). Across studies, SCD prevalence was higher in men than women, in lower levels of education, in Asian and Black African people compared to White people, in lower- and middle-income countries compared to high-income countries, and in studies conducted in later decades. Conclusions SCD is frequent in old age. Having a quarter of older individuals with SCD warrants further investigation of its significance, as a risk stage for AD and other dementias, and of ways to help individuals with SCD who seek medical advice. Moreover, a standardized instrument to measure SCD is needed to overcome the measurement variability currently dominant in the field.
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    Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: A COSMIC study
    (BioMed Central Ltd, 2020-05-26) Röhr S; Pabst A; Riedel-Heller SG; Jessen F; Turana Y; Handajani YS; Brayne C; Matthews FE; Stephan BCM; Lipton RB; Katz MJ; Wang C; Guerchet M; Preux P-M; Mbelesso P; Ritchie K; Ancelin M-L; Carrière I; Guaita A; Davin A; Vaccaro R; Kim KW; Han JW; Suh SW; Shahar S; Din NC; Vanoh D; van Boxtel M; Köhler S; Ganguli M; Jacobsen EP; Snitz BE; Anstey KJ; Cherbuin N; Kumagai S; Chen S; Narazaki K; Ng TP; Gao Q; Gwee X; Brodaty H; Kochan NA; Trollor J; Lobo A; López-Antón R; Santabárbara J; Crawford JD; Lipnicki DM; Sachdev PS; for Cohort Studies of Memory in an International Consortium (COSMIC)
    Background Subjective cognitive decline (SCD) is recognized as a risk stage for Alzheimer’s disease (AD) and other dementias, but its prevalence is not well known. We aimed to use uniform criteria to better estimate SCD prevalence across international cohorts. Methods We combined individual participant data for 16 cohorts from 15 countries (members of the COSMIC consortium) and used qualitative and quantitative (Item Response Theory/IRT) harmonization techniques to estimate SCD prevalence. Results The sample comprised 39,387 cognitively unimpaired individuals above age 60. The prevalence of SCD across studies was around one quarter with both qualitative harmonization/QH (23.8%, 95%CI = 23.3–24.4%) and IRT (25.6%, 95%CI = 25.1–26.1%); however, prevalence estimates varied largely between studies (QH 6.1%, 95%CI = 5.1–7.0%, to 52.7%, 95%CI = 47.4–58.0%; IRT: 7.8%, 95%CI = 6.8–8.9%, to 52.7%, 95%CI = 47.4–58.0%). Across studies, SCD prevalence was higher in men than women, in lower levels of education, in Asian and Black African people compared to White people, in lower- and middle-income countries compared to high-income countries, and in studies conducted in later decades. Conclusions SCD is frequent in old age. Having a quarter of older individuals with SCD warrants further investigation of its significance, as a risk stage for AD and other dementias, and of ways to help individuals with SCD who seek medical advice. Moreover, a standardized instrument to measure SCD is needed to overcome the measurement variability currently dominant in the field.
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    Lifestyle and incident dementia: A COSMIC individual participant data meta-analysis
    (Wiley Periodicals LLC on behalf of Alzheimer's Association, 2024-06-16) Van Asbroeck S; Köhler S; van Boxtel MPJ; Lipnicki DM; Crawford JD; Castro-Costa E; Lima-Costa MF; Blay SL; Shifu X; Wang T; Yue L; Lipton RB; Katz MJ; Derby CA; Guerchet M; Preux P-M; Mbelesso P; Norton J; Ritchie K; Skoog I; Najar J; Sterner TR; Scarmeas N; Yannakoulia M; Dardiotis T; Rolandi E; Davin A; Rossi M; Gureje O; Ojagbemi A; Bello T; Kim KW; Han JW; Oh DJ; Trompet S; Gussekloo J; Riedel-Heller SG; Röhr S; Pabst A; Shahar S; Rivan NFM; Singh DKA; Jacobsen E; Ganguli M; Hughes T; Haan M; Aiello AE; Ding D; Zhao Q; Xiao Z; Narazaki K; Chen T; Chen S; Ng TP; Gwee X; Gao Q; Brodaty H; Trollor J; Kochan N; Lobo A; Santabárbara J; Gracia-Garcia P; Sachdev PS; Deckers K; for Cohort Studies of Memory in an International Consortium (COSMIC)
    INTRODUCTION: The LIfestyle for BRAin Health (LIBRA) index yields a dementia risk score based on modifiable lifestyle factors and is validated in Western samples. We investigated whether the association between LIBRA scores and incident dementia is moderated by geographical location or sociodemographic characteristics. METHODS: We combined data from 21 prospective cohorts across six continents (N = 31,680) and conducted cohort-specific Cox proportional hazard regression analyses in a two-step individual participant data meta-analysis. RESULTS: A one-standard-deviation increase in LIBRA score was associated with a 21% higher risk for dementia. The association was stronger for Asian cohorts compared to European cohorts, and for individuals aged ≤75 years (vs older), though only within the first 5 years of follow-up. No interactions with sex, education, or socioeconomic position were observed. DISCUSSION: Modifiable risk and protective factors appear relevant for dementia risk reduction across diverse geographical and sociodemographic groups. HIGHLIGHTS: - A two-step individual participant data meta-analysis was conducted. - This was done at a global scale using data from 21 ethno-regionally diverse cohorts. - The association between a modifiable dementia risk score and dementia was examined. - The association was modified by geographical region and age at baseline. - Yet, modifiable dementia risk and protective factors appear relevant in all investigated groups and regions.
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    Sex differences in dementia risk and risk factors: Individual-participant data analysis using 21 cohorts across six continents from the COSMIC consortium.
    (John Wiley and Sons, Inc., 2023-08-01) Gong J; Harris K; Lipnicki DM; Castro-Costa E; Lima-Costa MF; Diniz BS; Xiao S; Lipton RB; Katz MJ; Wang C; Preux P-M; Guerchet M; Gbessemehlan A; Ritchie K; Ancelin M-L; Skoog I; Najar J; Sterner TR; Scarmeas N; Yannakoulia M; Kosmidis MH; Guaita A; Rolandi E; Davin A; Gureje O; Trompet S; Gussekloo J; Riedel-Heller S; Pabst A; Röhr S; Shahar S; Singh DKA; Rivan NFM; Boxtel MV; Köhler S; Ganguli M; Chang C-C; Jacobsen E; Haan M; Ding D; Zhao Q; Narazaki K; Chen T; Chen S; Ng TP; Gwee X; Numbers K; Mather KA; Scazufca M; Lobo A; De-la-Cámara C; Lobo E; Sachdev PS; Brodaty H; Hackett ML; Peters SAE; Woodward M
    INTRODUCTION: Sex differences in dementia risk, and risk factor (RF) associations with dementia, remain uncertain across diverse ethno-regional groups. METHODS: A total of 29,850 participants (58% women) from 21 cohorts across six continents were included in an individual participant data meta-analysis. Sex-specific hazard ratios (HRs), and women-to-men ratio of hazard ratios (RHRs) for associations between RFs and all-cause dementia were derived from mixed-effect Cox models. RESULTS: Incident dementia occurred in 2089 (66% women) participants over 4.6 years (median). Women had higher dementia risk (HR, 1.12 [1.02, 1.23]) than men, particularly in low- and lower-middle-income economies. Associations between longer education and former alcohol use with dementia risk (RHR, 1.01 [1.00, 1.03] per year, and 0.55 [0.38, 0.79], respectively) were stronger for men than women; otherwise, there were no discernible sex differences in other RFs. DISCUSSION: Dementia risk was higher in women than men, with possible variations by country-level income settings, but most RFs appear to work similarly in women and men.