| 1. |
- Wetterberg, Hanna, et al.
(författare)
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Representativeness in population-based studies of older adults: five waves of cross-sectional examinations in the Gothenburg H70 Birth Cohort Study
- 2022
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Ingår i: Bmj Open. - : BMJ. - 2044-6055. ; 12:12
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo describe representativeness in the Gothenburg H70 1930 Birth Cohort Study.DesignRepeated cross-sectional examinations of a population-based study.SettingGothenburg, Sweden.ParticipantsAll residents of Gothenburg, Sweden, born on specific birth dates in 1930 were invited to a comprehensive health examination at ages 70, 75, 79, 85 and 88. The number of participants at each examination was 524 at age 70, 767 at age 75, 580 at age 79, 416 at age 85, and 258 at age 88.Primary outcome measuresWe compared register data on sociodemographic characteristics and hospital discharge diagnoses between participants and (1) refusals, (2) all same-aged individuals in Gothenburg and (3) all same-aged individuals in Sweden. We also compared mortality rates between participants and refusals.ResultsRefusal rate increased with age. At two or more examination waves, participants compared with refusals had higher educational level, more often had osteoarthritis, had lower mortality rates, had lower prevalence of neuropsychiatric, alcohol-related and cardiovascular disorders, and were more often married. At two examination waves, participants compared with same-aged individuals in Gothenburg had higher education and were more often born in Sweden. At two examination waves or more, participants compared with same-aged individuals in Sweden had higher education, had higher average income, less often had ischaemic heart disease, were less often born in Sweden and were more often divorced.ConclusionsParticipants were more similar to the target population in Gothenburg than to refusals and same-aged individuals in Sweden. Our study shows the importance of having different comparison groups when assessing representativeness of population studies, which is important in evaluating generalisability of results. The study also contributes unique and up-to-date knowledge about participation bias in these high age groups.
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| 2. |
- Badji, A., et al.
(författare)
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Cerebrospinal Fluid Biomarkers, Brain Structural and Cognitive Performances Between Normotensive and Hypertensive Controlled, Uncontrolled and Untreated 70-Year-Old Adults
- 2022
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Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypertension is an important risk factor for Alzheimer's disease (AD). The pathophysiological mechanisms underlying the relationship between AD and hypertension are not fully understood, but they most likely involve microvascular dysfunction and cerebrovascular pathology. Although previous studies have assessed the impact of hypertension on different markers of brain integrity, no study has yet provided a comprehensive comparison of cerebrospinal fluid (CSF) biomarkers and structural brain differences between normotensive and hypertensive groups in a single and large cohort of older adults in relationship to cognitive performances.Objective: The aim of the present work was to investigate the differences in cognitive performances, CSF biomarkers and magnetic resonance imaging (MRI) of brain structure between normotensive, controlled hypertensive, uncontrolled hypertensive, and untreated hypertensive older adults from the Gothenburg H70 Birth Cohort Studies.Methods: As an indicator of vascular brain pathology, we measured white matter hyperintensities (WMHs), lacunes, cerebral microbleeds, enlarged perivascular space (epvs), and fractional anisotropy (FA). To assess markers of AD pathology/neurodegeneration, we measured hippocampal volume, temporal cortical thickness on MRI, and amyloid-beta(42), phosphorylated tau, and neurofilament light protein (NfL) in cerebrospinal fluid. Various neuropsychological tests were used to assess performances in memory, attention/processing speed, executive function, verbal fluency, and visuospatial abilities.Results: We found more white matter pathology in hypertensive compared to normotensive participants, with the highest vascular burden in uncontrolled participants (e.g., lower FA, more WMHs, and epvs). No significant difference was found in any MRI or CSF markers of AD pathology/neurodegeneration when comparing normotensive and hypertensive participants, nor among hypertensive groups. No significant difference was found in most cognitive functions between groups.Conclusion: Our results suggest that good blood pressure control may help prevent cerebrovascular pathology. In addition, hypertension may contribute to cognitive decline through its effect on cerebrovascular pathology rather than AD-related pathology. These findings suggest that hypertension is associated with MRI markers of vascular pathology in the absence of a significant decline in cognitive functions.
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| 3. |
- Skillbäck, Tobias, et al.
(författare)
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Slowing gait speed precedes cognitive decline by several years
- 2022
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 18:9, s. 1667-1676
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In this longitudinal study, we aimed to examine if slowing gait speed preceded cognitive decline and correlated with brain amyloidosis. Methods: The sample (n = 287) was derived from the Gothenburg H70 Birth Cohort Studies, with follow-ups between 2000 and 2015. Gait speed was measured by indoor walk, and cognition using the Clinical Dementia Rating (CDR) score. All participants had CDR = 0 at baseline. Some participants had data on cerebrospinal fluid (CSF) amyloid beta (Aβ)1-42 concentrations at the 2009 examination. Results: Gait speed for participants who worsened in CDR score during follow-up was slower at most examinations. Baseline gait speed could significantly predict CDR change from baseline to follow-up. Subjects with pathological CSF Aβ1-42 concentrations at the 2009 visit had lost more gait speed compared to previous examinations. Discussion: Our results indicate that gait speed decline precedes cognitive decline, is linked to Alzheimer's pathology, and might be used for early detection of increased risk for dementia development. © 2021 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association
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| 4. |
- Öhman, Fredrik, et al.
(författare)
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Smartphone-based long-term delayed memory performance is associated with the Preclinical Alzheimer's Cognitive Composite and CSF levels of β-amyloid.
- 2022
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Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279. ; 18:S2
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Tidskriftsartikel (refereegranskat)abstract
- Remote and unsupervised cognitive testing using smartphones may improve sensitivity to detect preclinical Alzheimer's disease (AD). In particular, cognitive testing at-home enables the evaluation of the potentially more sensitive long-term delayed memory retrieval, which is commonly not feasible in a clinical setting.Here, we investigated the association between remote and unsupervised smartphone-based cognitive assessments and in-clinic cognitive measurement in older participants (CDR = 0, MMSE = 29.2, age = 77). The sample (non-demented at age 70) was derived from the Swedish population-based Gothenburg H70 Birth Cohort Studies. In a subsample of participants, the retrospective correlation with cerebrospinal fluid (CSF) biomarkers analyzed at age 70 was further explored. To this point, 177 H70-participants have consented and were enrolled into the smartphone sub-study. They completed an "Object-in-Room Recall Test" (ORR) remotely and unsupervised using own mobile devices, and the recall session was initiated 24 hours after the initial learning phase. Available previously assessed CSF measures included the Aβ42/Aβ40-ratio, t-tau, p-tau, neurofilament light (NFL), and neurogranin, available in-clinic cognitive tests included the Rey Auditory Verbal Learning Test (RAVLT), Semantic Fluency, Digit-Symbol-Coding, and Mini Mental State Examination. The above-mentioned cognitive tests were used to derive the Preclinical Alzheimer's Cognitive Composite (PACC5), a composite designed to be sensitive to cognitive change in preclinical AD. All associations were examined using Pearson correlation coefficient.Preliminary analyses in a subset of participants yielded relatively strong positive correlations between PACC5 (R = .50, p<.001) and the ORR Long-term Delayed Retrieval. The strongest correlation for an individual test was observed between the RAVLT Delayed Retrieval and the ORR Long-term Delayed Retrieval (R = .52, p<.001). Regarding the CSF biomarkers, Aβ42/Aβ40-ratio at age 70 was positively correlated with the ORR Long-term Delayed Retrieval at age 77 (R = .43, p<.01), while measures of t-tau, p-tau, NFL, and neurogranin at age 70 were not.Our findings demonstrate the potential of smartphone-based cognitive assessment to detect features of preclinical AD in a population-based sample of older adults. Future analyses will address the relationship between these novel cognitive measures in relation to longitudinal CSF- and neuroimaging-based biomarkers and clinical progression.
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| 5. |
- Öhman, Fredrik, et al.
(författare)
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Unsupervised mobile app-based cognitive testing in a population-based study of older adults born 1944
- 2022
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Ingår i: Frontiers in Digital Health. - : Frontiers Media SA. - 2673-253X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mobile app-based tools have the potential to yield rapid, cost-effective, and sensitive measures for detecting dementia-related cognitive impairment in clinical and research settings. At the same time, there is a substantial need to validate these tools in real-life settings. The primary aim of this study was thus to evaluate the feasibility, validity, and reliability of mobile app-based tasks for assessing cognitive function in a population-based sample of older adults. Method: A total of 172 non-demented (Clinical Dementia Rating 0 and 0.5) older participants (aged 76–77) completed two mobile app-based memory tasks—the Mnemonic Discrimination Task for Objects and Scenes (MDT-OS) and the long-term (24h) delayed Object-In-Room Recall Task (ORR-LDR). To determine the validity of the tasks for measuring relevant cognitive functions in this population, we assessed relationships with conventional cognitive tests. In addition, psychometric properties, including test-retest reliability, and the participants’ self-rated experience with mobile app-based cognitive tasks were assessed. Result: MDT-OS and ORR-LDR were weakly-to-moderately correlated with the Preclinical Alzheimer's Cognitive Composite (PACC5) (r = 0.3–0.44, p <.001) and with several other measures of episodic memory, processing speed, and executive function. Test-retest reliability was poor–to-moderate for one single session but improved to moderate–to-good when using the average of two sessions. We observed no significant floor or ceiling effects nor effects of education or gender on task performance. Contextual factors such as distractions and screen size did not significantly affect task performance. Most participants deemed the tasks interesting, but many rated them as highly challenging. While several participants reported distractions during tasks, most could concentrate well. However, there were difficulties in completing delayed recall tasks on time in this unsupervised and remote setting. Conclusion: Our study proves the feasibility of mobile app-based cognitive assessments in a community sample of older adults, demonstrating its validity in relation to conventional cognitive measures and its reliability for repeated measurements over time. To further strengthen study adherence, future studies should implement additional measures to improve task completion on time.
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