Browsing by Author "Kochan NA"

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Subjective cognitive decline and rates of incident Alzheimer's disease and non–Alzheimer's disease dementia.
    (John Wiley and Sons Inc on behalf of The Alzheimer's Association, 2019-03) Slot RER; Sikkes SAM; Berkhof J; Brodaty H; Buckley R; Cavedo E; Dardiotis E; Guillo-Benarous F; Hampel H; Kochan NA; Lista S; Luck T; Maruff P; Molinuevo JL; Kornhuber J; Reisberg B; Riedel-Heller SG; Risacher SL; Roehr S; Sachdev PS; Scarmeas N; Scheltens P; Shulman MB; Saykin AJ; Verfaillie SCJ; Visser PJ; Vos SJB; Wagner M; Wolfsgruber S; Jessen F; Alzheimer's Disease Neuroimaging Initiative; DESCRIPA working group; INSIGHT-preAD study group; SCD-I working group; van der Flier WM
    Introduction In this multicenter study on subjective cognitive decline (SCD) in community-based and memory clinic settings, we assessed the (1) incidence of Alzheimer's disease (AD) and non-AD dementia and (2) determinants of progression to dementia. Methods Eleven cohorts provided 2978 participants with SCD and 1391 controls. We estimated dementia incidence and identified risk factors using Cox proportional hazards models. Results In SCD, incidence of dementia was 17.7 (95% Poisson confidence interval 15.2-20.3)/1000 person-years (AD: 11.5 [9.6-13.7], non-AD: 6.1 [4.7-7.7]), compared with 14.2 (11.3-17.6) in controls (AD: 10.1 [7.7-13.0], non-AD: 4.1 [2.6-6.0]). The risk of dementia was strongly increased in SCD in a memory clinic setting but less so in a community-based setting. In addition, higher age (hazard ratio 1.1 [95% confidence interval 1.1-1.1]), lower Mini–Mental State Examination (0.7 [0.66-0.8]), and apolipoprotein E ε4 (1.8 [1.3-2.5]) increased the risk of dementia. Discussion SCD can precede both AD and non-AD dementia. Despite their younger age, individuals with SCD in a memory clinic setting have a higher risk of dementia than those in community-based cohorts.
  • Thumbnail Image
    Item
    Trajectory of Cognitive Decline Before and After Stroke in 14 Population Cohorts
    (American Medical Association, 2024-10-02) Lo JW; Crawford JD; Lipnicki DM; Lipton RB; Katz MJ; Preux P-M; Guerchet M; d'Orsi E; Quialheiro A; Rech CR; Ritchie K; Skoog I; Najar J; Sterner TR; Rolandi E; Davin A; Rossi M; Riedel-Heller SG; Pabst A; Röhr S; Ganguli M; Jacobsen E; Snitz BE; Anstey KJ; Aiello AE; Brodaty H; Kochan NA; Chen Y-C; Chen J-H; Sanchez-Juan P; Del Ser T; Valentí M; Lobo A; De-la-Cámara C; Lobo E; Sachdev PS
    IMPORTANCE: Poststroke cognitive impairment is common, but the cognitive trajectory following a first stroke, relative to prestroke cognitive function, remains unclear. OBJECTIVE: To map the trajectory of cognitive function before any stroke and after stroke in global cognition and in 4 cognitive domains, as well as to compare the cognitive trajectory prestroke in stroke survivors with the trajectory of individuals without incident stroke over follow-up. DESIGN, SETTING, AND PARTICIPANTS: The study used harmonized and pooled data from 14 population-based cohort studies included in the Cohort Studies of Memory in an International Consortium collaboration. These studies were conducted from 1993 to 2019 across 11 countries among community-dwelling older adults without a history of stroke or dementia. For this study, linear mixed-effects models were used to estimate trajectories of cognitive function poststroke relative to a stroke-free cognitive trajectory. The full model adjusted for demographic and vascular risk factors. Data were analyzed from July 2022 to March 2024. EXPOSURE: Incident stroke. MAIN OUTCOMES AND MEASURES: The primary outcome was global cognition, defined as the standardized average of 4 cognitive domains (language, memory, processing speed, and executive function). Cognitive domain scores were formed by selecting the most commonly administered test within each domain and standardizing the scores. RESULTS: The study included 20 860 participants (12 261 [58.8%] female) with a mean (SD) age of 72.9 (8.0) years and follow-up of 7.51 (4.2) years. Incident stroke was associated with a substantial acute decline in global cognition (-0.25 SD; 95% CI, -0.33 to -0.17 SD), the Mini-Mental State Examination, and all cognitive domains (ranging from -0.17 SD to -0.22 SD), as well as accelerated decline in global cognition (-0.038 SD per year; 95% CI, -0.057 to -0.019 SD per year) and all domains except memory (ranging from -0.020 to -0.055 SD per year), relative to a stroke-free cognitive trajectory. There was no significant difference in prestroke slope in stroke survivors compared with the rate of decline in individuals without stroke in all cognitive measures. The mean rate of decline without a previous stroke was -0.049 SD per year (95% CI, -0.051 to -0.047 SD) in global cognition. CONCLUSIONS AND RELEVANCE: In this cohort study using pooled data from 14 cohorts, incident stroke was associated with acute and accelerated long-term cognitive decline in older stroke survivors.