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1.
Lancet Public Health ; 5(1): e42-e50, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31837974

RESUMO

BACKGROUND: Social inequalities in mortality persist in high-income countries with universal health care, and the mechanisms by which these inequalities are generated remain unclear. We aimed to examine whether social inequalities were present before or after the onset of adverse health conditions (multimorbidity, frailty, and disability). METHODS: Our analysis was based on data from the ongoing Whitehall II cohort study, which enrolled British civil servants aged 35-55 years in 1985-88. Participants were assessed for three indicators of socioeconomic status (education, occupational position, and literacy) at age 50 years. Participants underwent clinical examinations (in 2002-04, 2007-09, 2012-13, and 2015-16) for assessment of frailty (two or more of low physical activity, slow walking speed, poor grip strength, weight loss, and exhaustion) and disability (two or more difficulties in bathing, dressing, going to the toilet, transferring, feeding, and walking). In addition, electronic health records were used to assess the incidence of multimorbidity (two or more of diabetes, coronary heart disease, stroke, chronic obstructive pulmonary disease, depression, arthritis, cancer, dementia, and Parkinson's disease) and mortality. In analyses adjusted for sociodemographic factors, we used multistate models to examine social inequalities in transitions from healthy state to adverse health conditions and subsequently to mortality. FINDINGS: Of 10 308 individuals in the Whitehall II study cohort, 6425 had relevant data available at 50 years and to the end of follow-up on Aug 31, 2017, and were included in our analysis. Participants were followed up for a median of 23·6 years (IQR 19·6-28·9). 1694 (26·4%) of 6425 participants developed multimorbidity, 1733 (27·0%) became frail, 692 (10·8%) had a disability, and 611 (9·5%) died. Multimorbidity (hazard ratio [HR] 4·12 [95% CI 3·41-4·98]), frailty (HR 2·38 [95% CI 1·93-2·93]), and disability (HR 1·73 [95% CI 1·34-2·22]) were associated with increased risk of mortality; these associations were not modified by socioeconomic status. In multistate models, occupation was the socioeconomic status indicator that was most strongly associated with inequalities in the transition from healthy state to multimorbidity (HR 1·54 [95% CI 1·37-1·73]), to frailty (HR 2·08 [95% CI 1·85-2·33]), and to disability (HR 1·44 [95% CI 1·18-1·74]). Socioeconomic status indicators did not affect transitions to mortality in those with multimorbidity, frailty, or disability. INTERPRETATION: Socioeconomic status affects the risk of multimorbidity, frailty, and disability, but does not affect the risk of mortality after the onset of these adverse health conditions. Therefore, primary prevention is key to reducing social inequalities in mortality. Of the three adverse health conditions, multimorbidity had the strongest association with mortality, making it a central target for improving population health. FUNDING: UK Medical Research Council; National Institute on Aging, National Institutes of Health; British Heart Foundation.

2.
Diabetologia ; 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792574

RESUMO

AIMS/HYPOTHESIS: This work examined the role of physical activity in the course of diabetes using data spanning nearly three decades. Our first aim was to examine the long-term association of moderate and vigorous physical activity with incidence of type 2 diabetes. Our second aim was to investigate the association of moderate-to-vigorous physical activity post-diabetes diagnosis with subsequent risk of all-cause and cardiovascular disease mortality. METHODS: A total of 9987 participants from the Whitehall II cohort study free of type 2 diabetes at baseline (1985-1988) were followed for incidence of type 2 diabetes, based on clinical assessments between 1985 and 2016 and linkage to electronic health records up to 31 March 2017. We first examined the association of moderate and vigorous physical activity measured by questionnaire in 1985-1988 (mean age 44.9 [SD 6.0] years; women, 32.7%) with incident type 2 diabetes, using the interval-censored, illness-death model, a competing risk analysis that takes into account both competing risk of death and intermittent ascertainment of diabetes due to reliance on data collection cycles (interval-censored). The second analysis was based on individuals with type 2 diabetes over the follow-up period where we used Cox regression with inverse probability weighting to examine the association of moderate-to-vigorous physical activity after diagnosis of type 2 diabetes with risk of all-cause and cardiovascular disease mortality. RESULTS: Of the 9987 participants, 1553 developed type 2 diabetes during a mean follow-up of 27.1 (SD 6.3) years. Compared with participants who were inactive in 1985-1988, those who undertook any duration of moderate-to-vigorous physical activity had a lower risk of type 2 diabetes (HR 0.85 [95% CI 0.75, 0.97], p = 0.02; analysis adjusted for sociodemographic, behavioural and health-related factors). In 1026 participants with a diagnosis of type 2 diabetes over the follow-up period, data on moderate-to-vigorous physical activity after diabetes diagnosis were available; 165 all-cause deaths and 55 cardiovascular disease-related deaths were recorded during a mean follow-up of 8.8 (SD 6.1) years. In these participants with diabetes, any duration of moderate-to-vigorous physical activity was associated with lower all-cause mortality (HR 0.61 [95% CI 0.41, 0.93], p = 0.02) while the association with cardiovascular mortality was evident only for physical activity undertaken at or above recommendations (≥2.5 h per week of moderate-to-vigorous physical activity or ≥1.25 h per week of vigorous physical activity; HR 0.40 [95% CI 0.16, 0.96], p = 0.04) in fully adjusted models. CONCLUSIONS/INTERPRETATION: Moderate-to-vigorous physical activity plays an important role in diabetes, influencing both its incidence and prognosis. A protective effect on incidence was seen for durations of activity below recommendations and a marginal additional benefit was observed at higher durations. Among individuals with type 2 diabetes, any duration of moderate-to-vigorous physical activity was associated with reduced all-cause mortality while recommended durations of physical activity were required for protection against cardiovascular disease-related mortality. DATA AVAILABILITY: Whitehall II data, protocols and other metadata are available to the scientific community. Please refer to the Whitehall II data sharing policy at https://www.ucl.ac.uk/epidemiology-health-care/research/epidemiology-and-public-health/research/whitehall-ii/data-sharing.

3.
Eur J Epidemiol ; 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31776832

RESUMO

Aortic stiffness is associated with an increased risk of cardio- and cerebrovascular disease and mortality and may increase risk of dementia. The aim of the present study is to examine the association between arterial stiffness and cognitive decline in a large prospective cohort study with three repeated cognitive assessment over 7 years of follow-up. Aortic pulse wave velocity (PWV) was measured among 4300 participants (mean ± standard deviation age 65.1 ± 5.2 years) in 2007-2009 and categorized based on the tertiles: (lowest third: < 7.41 m/s), (middle third: 7.41-8.91 m/s), and (highest third: > 8.91 m/s). A global cognitive score was calculated in 2007-2009, 2012-2013, and 2015-2016 based on responses to memory, reasoning and fluency tests. Standardized global cognitive score (mean = 0, SD = 1) in highest third versus lowest third of PWV category was lower at baseline (- 0.12, 95% CI - 0.18, - 0.06). Accelerated 7-year cognitive decline was observed among individuals with the highest PWV [difference in 7-year cognitive change for highest third versus lowest third PWV: - 0.06, 95% CI - 0.11, - 0.01, P < 0.01]. Higher aortic stiffness was associated with faster cognitive decline. Clinicians may be able to use arterial stiffness severity as an indicator to administer prompt treatments to prevent or delay the onset of cognitive decline or dementia. Future studies need to determine whether early intervention of vascular stiffness is effective in delaying these outcomes.

4.
Diabetes Care ; 42(10): 1903-1911, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31451533

RESUMO

OBJECTIVE: Frailty is a dynamic state of vulnerability in the elderly. We examined whether individuals with overt diabetes or higher levels of HbA1c or fasting plasma glucose (FG) experience different frailty trajectories with aging. RESEARCH DESIGN AND METHODS: Diabetes, HbA1c, and FG were assessed at baseline, and frailty status was evaluated with a 36-item frailty index every 2 years during a 10-year follow-up among participants from the English Longitudinal Study of Ageing (ELSA). Mixed-effects models with age as time scale were used to assess whether age trajectories of frailty differed as a function of diabetes, HbA1c, and FG. RESULTS: Among 5,377 participants (median age [interquartile range] 70 [65, 77] years, 45% men), 35% were frail at baseline. In a model adjusted for sex, participants with baseline diabetes had an increased frailty index over aging compared with those without diabetes. Similar findings were observed with higher levels of HbA1c, while FG was not associated with frailty. In a model additionally adjusted for income, social class, smoking, alcohol, and hemoglobin, only diabetes was associated with an increased frailty index. Among nonfrail participants at baseline, both diabetes and HbA1c level were associated with a higher increased frailty index over time. CONCLUSIONS: People with diabetes or higher HbA1c levels at baseline had a higher frailty level throughout later life. Nonfrail participants with diabetes or higher HbA1c also experienced more rapid deterioration of frailty level with aging. This observation could reflect a role of diabetes complications in frailty trajectories or earlier shared determinants that contribute to diabetes and frailty risk in later life.

5.
PLoS Med ; 16(8): e1002862, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31374073

RESUMO

BACKGROUND: There is need to identify targets for preventing or delaying dementia. Social contact is a potential target for clinical and public health studies, but previous observational studies had short follow-up, making findings susceptible to reverse causation bias. We therefore examined the association of social contact with subsequent incident dementia and cognition with 28 years' follow-up. METHODS AND FINDINGS: We conducted a retrospective analysis of the Whitehall II longitudinal prospective cohort study of employees of London civil service departments, aged 35-55 at baseline assessment in 1985-1988 and followed to 2017. Social contact was measured six times through a self-report questionnaire about frequency of contact with non-cohabiting relatives and friends. Dementia status was ascertained from three linked clinical and mortality databases, and cognition was assessed five times using tests of verbal memory, verbal fluency, and reasoning. Cox regression models with inverse probability weighting to account for attrition and missingness examined the association between social contact at age 50, 60, and 70 years and subsequent incident dementia. Mixed linear models examined the association of midlife social contact between 45 and 55 years and cognitive trajectory during the subsequent 14 years. Analyses were adjusted for age, sex, ethnicity, socioeconomic status, education, health behaviours, employment status, and marital status. Of 10,308 Whitehall II study participants, 10,228 provided social contact data (mean age 44.9 years [standard deviation (SD) 6.1 years] at baseline; 33.1% female; 89.1% white ethnicity). More frequent social contact at age 60 years was associated with lower dementia risk (hazard ratio [HR] for each SD higher social contact frequency = 0.88 [95% CI 0.79, 0.98], p = 0.02); effect size of the association of social contact at 50 or 70 years with dementia was similar (0.92 [95% CI 0.83, 1.02], p = 0.13 and 0.91 [95% CI 0.78, 1.06], p = 0.23, respectively) but not statistically significant. The association between social contact and incident dementia was driven by contact with friends (HR = 0.90 [95% CI 0.81, 1.00], p = 0.05), but no association was found for contact with relatives. More frequent social contact during midlife was associated with better subsequent cognitive trajectory: global cognitive function was 0.07 (95% CI 0.03, 0.11), p = 0.002 SDs higher for those with the highest versus lowest tertile of social contact frequency, and this difference was maintained over 14 years follow-up. Results were consistent in a series of post hoc analyses, designed to assess potential biases. A limitation of our study is ascertainment of dementia status from electronic health records rather than in-person assessment of diagnostic status, with the possibility that milder dementia cases were more likely to be missed. CONCLUSIONS: Findings from this study suggest a protective effect of social contact against dementia and that more frequent contact confers higher cognitive reserve, although it is possible that the ability to maintain more social contact may be a marker of cognitive reserve. Future intervention studies should seek to examine whether improving social contact frequency is feasible, acceptable, and efficacious in changing cognitive outcomes.


Assuntos
Disfunção Cognitiva/etiologia , Demência/etiologia , Relações Interpessoais , Adulto , Fatores Etários , Idoso , Disfunção Cognitiva/psicologia , Demência/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Rede Social , Fatores Socioeconômicos
6.
BMJ ; 366: l4466, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391161

RESUMO

OBJECTIVE: To quantify the association between major surgery and the age related cognitive trajectory. DESIGN: Prospective longitudinal cohort study. SETTING: United Kingdom. PARTICIPANTS: 7532 adults with as many as five cognitive assessments between 1997 and 2016 in the Whitehall II study, with linkage to hospital episode statistics. Exposures of interest included any major hospital admission, defined as requiring more than one overnight stay during follow-up. MAIN OUTCOMES MEASURES: The primary outcome was the global cognitive score established from a battery of cognitive tests encompassing reasoning, memory, and phonemic and semantic fluency. Bayesian linear mixed effects models were used to calculate the change in the age related cognitive trajectory after hospital admission. The odds of substantial cognitive decline induced by surgery defined as more than 1.96 standard deviations from a predicted trajectory (based on the first three cognitive waves of data) was also calculated. RESULTS: After accounting for the age related cognitive trajectory, major surgery was associated with a small additional cognitive decline, equivalent on average to less than five months of aging (95% credible interval 0.01 to 0.73 years). In comparison, admissions for medical conditions and stroke were associated with 1.4 (1.0 to 1.8) and 13 (9.6 to 16) years of aging, respectively. Substantial cognitive decline occurred in 2.5% of participants with no admissions, 5.5% of surgical admissions, and 12.7% of medical admissions. Compared with participants with no major hospital admissions, those with surgical or medical events were more likely to have substantial decline from their predicted trajectory (surgical admissions odds ratio 2.3, 95% credible interval 1.4 to 3.9; medical admissions 6.2, 3.4 to 11.0). CONCLUSIONS: Major surgery is associated with a small, long term change in the average cognitive trajectory that is less profound than for major medical admissions. The odds of substantial cognitive decline after surgery was about doubled, though lower than for medical admissions. During informed consent, this information should be weighed against the potential health benefits of surgery.


Assuntos
Transtornos Cognitivos/epidemiologia , Disfunção Cognitiva/epidemiologia , Hospitalização/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Adulto , Idoso , Transtornos Cognitivos/etiologia , Disfunção Cognitiva/etiologia , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos
7.
BMJ ; 366: l4414, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391187

RESUMO

OBJECTIVES: To examine the association between the Life Simple 7 cardiovascular health score at age 50 and incidence of dementia. DESIGN: Prospective cohort study. SETTING: Civil service departments in London (Whitehall II study; study inception 1985-88). PARTICIPANTS: 7899 participants with data on the cardiovascular health score at age 50. EXPOSURES: The cardiovascular health score included four behavioural (smoking, diet, physical activity, body mass index) and three biological (fasting glucose, blood cholesterol, blood pressure) metrics, coded on a three point scale (0, 1, 2). The cardiovascular health score was the sum of seven metrics (score range 0-14) and was categorised into poor (scores 0-6), intermediate (7-11), and optimal (12-14) cardiovascular health. MAIN OUTCOME MEASURE: Incident dementia, identified through linkage to hospital, mental health services, and mortality registers until 2017. RESULTS: 347 incident cases of dementia were recorded over a median follow-up of 24.7 years. Compared with an incidence rate of dementia of 3.2 (95% confidence interval 2.5 to 4.0) per 1000 person years among the group with poor cardiovascular health, the absolute rate differences per 1000 person years were -1.5 (95% confidence interval -2.3 to -0.7) for the group with intermediate cardiovascular health and -1.9 (-2.8 to -1.1) for the group with optimal cardiovascular health. Higher cardiovascular health score was associated with a lower risk of dementia (hazard ratio 0.89 (0.85 to 0.95) per 1 point increment in the cardiovascular health score). Similar associations with dementia were observed for the behavioural and biological subscales (hazard ratios per 1 point increment in the subscores 0.87 (0.81 to 0.93) and 0.91 (0.83 to 1.00), respectively). The association between cardiovascular health at age 50 and dementia was also seen in people who remained free of cardiovascular disease over the follow-up (hazard ratio 0.89 (0.84 to 0.95) per 1 point increment in the cardiovascular health score). CONCLUSION: Adherence to the Life Simple 7 ideal cardiovascular health recommendations in midlife was associated with a lower risk of dementia later in life.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Demência/epidemiologia , Nível de Saúde , Estilo de Vida Saudável , Adulto , Idoso , Doenças Cardiovasculares/sangue , Demência/prevenção & controle , Feminino , Seguimentos , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
8.
Sci Rep ; 9(1): 10270, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31311982

RESUMO

The association between physical activity and lung function is thought to depend on smoking history but most previous research uses self-reported measures of physical activity. This cross-sectional study investigates whether the association between accelerometer-derived physical activity and lung function in older adults differs by smoking history. The sample comprised 3063 participants (age = 60-83 years) who wore an accelerometer during 9 days and undertook respiratory function tests. Forced vital capacity (FVC) was associated with moderate-to-vigorous physical activity (MVPA; acceleration ≥0.1 g (gravity)) in smokers but not in never smokers: FVC differences for 10 min increase in MVPA were 58.6 (95% Confidence interval: 21.1, 96.1), 27.8 (4.9, 50.7), 16.6 (7.9, 25.4), 2.8 (-5.2, 10.7) ml in current, recent ex-, long-term ex-, and never-smokers, respectively. A similar trend was observed for forced expiratory volume in 1 second. Functional data analysis, a threshold-free approach using the entire accelerometry distribution, showed an association between physical activity and lung function in all smoking groups, with stronger association in current and recent ex-smokers than in long-term ex- and never-smokers; the associations were evident in never smokers only at activity levels above the conventional 0.1 g MVPA threshold. These findings suggest that the association between lung function and physical activity in older adults is more pronounced in smokers than non-smokers.

9.
PLoS One ; 14(5): e0217026, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31086391

RESUMO

OBJECTIVE: To investigate the relationship between cerebrospinal fluid (CSF) ß-amyloid peptide (Aß42) and CSF Tau in a large population of patients referred to memory clinics for investigation of cognitive dysfunction. METHODS: We analyzed Alzheimer's disease (AD) biomarkers in CSF taken from 3565 patients referred to 18 French memory clinics. Patients were classified into four profiles according to levels of CSF biomarkers (A: amyloidosis, N: neurodegeneration). The association between CSF Tau and CSF Aß42 were analyzed using general linear regression models, in the overall population and stratified by biomarkers profiles. We compared linear and quadratic models using Akaike information criterion. We also assessed change in biomarker profiles in a subset of patients who had 2 assessments of biomarkers. RESULTS: CSF Tau was negatively associated with CSF Aß42 in the overall population, following a non-linear quadratic model. However, the nature of this association was different in the 4 profiles: positive association in A-N- profile, negative association in A-N+ and A+N+ profiles, lack of association in A+N- patients. When considering patients with longitudinal data on profiles, 36% of those initially classified as A-N+ evolved to an A+N+ profile. CONCLUSIONS: The nature of the association between CSF Aß42 and CFS Tau depends on the A/N profiles of patients. These results suggest an increase in CSF Aß42 early in the disease before its decline while tau pathology progresses, this pattern is particularly observed in non-APOE4 subjects. This phenomenon may explain why some patients with neurodegeneration only markers convert to an AD profile (A+N+) over time.

10.
BMJ ; 365: l1495, 2019 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-30995986

RESUMO

OBJECTIVE: To examine whether physical inactivity is a risk factor for dementia, with attention to the role of cardiometabolic disease in this association and reverse causation bias that arises from changes in physical activity in the preclinical (prodromal) phase of dementia. DESIGN: Meta-analysis of 19 prospective observational cohort studies. DATA SOURCES: The Individual-Participant-Data Meta-analysis in Working Populations Consortium, the Inter-University Consortium for Political and Social Research, and the UK Data Service, including a total of 19 of a potential 9741 studies. REVIEW METHOD: The search strategy was designed to retrieve individual-participant data from prospective cohort studies. Exposure was physical inactivity; primary outcomes were incident all-cause dementia and Alzheimer's disease; and the secondary outcome was incident cardiometabolic disease (that is, diabetes, coronary heart disease, and stroke). Summary estimates were obtained using random effects meta-analysis. RESULTS: Study population included 404 840 people (mean age 45.5 years, 57.7% women) who were initially free of dementia, had a measurement of physical inactivity at study entry, and were linked to electronic health records. In 6.0 million person-years at risk, we recorded 2044 incident cases of all-cause dementia. In studies with data on dementia subtype, the number of incident cases of Alzheimer's disease was 1602 in 5.2 million person-years. When measured <10 years before dementia diagnosis (that is, the preclinical stage of dementia), physical inactivity was associated with increased incidence of all-cause dementia (hazard ratio 1.40, 95% confidence interval 1.23 to 1.71) and Alzheimer's disease (1.36, 1.12 to 1.65). When reverse causation was minimised by assessing physical activity ≥10 years before dementia onset, no difference in dementia risk between physically active and inactive participants was observed (hazard ratios 1.01 (0.89 to 1.14) and 0.96 (0.85 to 1.08) for the two outcomes). Physical inactivity was consistently associated with increased risk of incident diabetes (hazard ratio 1.42, 1.25 to 1.61), coronary heart disease (1.24, 1.13 to 1.36), and stroke (1.16, 1.05 to 1.27). Among people in whom cardiometabolic disease preceded dementia, physical inactivity was non-significantly associated with dementia (hazard ratio for physical activity assessed >10 before dementia onset 1.30, 0.79 to 2.14). CONCLUSIONS: In analyses that addressed bias due to reverse causation, physical inactivity was not associated with all-cause dementia or Alzheimer's disease, although an indication of excess dementia risk was observed in a subgroup of physically inactive individuals who developed cardiometabolic disease.


Assuntos
Demência/epidemiologia , Síndrome Metabólica/epidemiologia , Comportamento Sedentário , Demência/etiologia , Humanos , Incidência , Síndrome Metabólica/etiologia , Estudos Observacionais como Assunto , Fatores de Risco , Reino Unido/epidemiologia
11.
Nat Commun ; 10(1): 1585, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30952852

RESUMO

Sleep is an essential human function but its regulation is poorly understood. Using accelerometer data from 85,670 UK Biobank participants, we perform a genome-wide association study of 8 derived sleep traits representing sleep quality, quantity and timing, and validate our findings in 5,819 individuals. We identify 47 genetic associations at P < 5 × 10-8, of which 20 reach a stricter threshold of P < 8 × 10-10. These include 26 novel associations with measures of sleep quality and 10 with nocturnal sleep duration. The majority of identified variants associate with a single sleep trait, except for variants previously associated with restless legs syndrome. For sleep duration we identify a missense variant (p.Tyr727Cys) in PDE11A as the likely causal variant. As a group, sleep quality loci are enriched for serotonin processing genes. Although accelerometer-derived measures of sleep are imperfect and may be affected by restless legs syndrome, these findings provide new biological insights into sleep compared to previous efforts based on self-report sleep measures.


Assuntos
Polissonografia/métodos , Transtornos do Sono-Vigília/genética , Sono/genética , Acelerometria/métodos , Ritmo Circadiano , Humanos , Polimorfismo de Nucleotídeo Único , Serotonina/genética , Serotonina/metabolismo , Transtornos do Sono-Vigília/diagnóstico , Relação Cintura-Quadril
12.
JAMA ; 321(10): 957-968, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30860560

RESUMO

Importance: Observational studies suggest that diet is linked to cognitive health. However, the duration of follow-up in many studies is not sufficient to take into account the long preclinical phase of dementia, and the evidence from interventional studies is not conclusive. Objective: To examine whether midlife diet is associated with subsequent risk for dementia. Design, Setting, and Participants: Population-based cohort study established in 1985-1988 that had dietary intake assessed in 1991-1993, 1997-1999, and 2002-2004 and follow-up for incident dementia until March 31, 2017. Exposures: Food frequency questionnaire to derive the Alternate Healthy Eating Index (AHEI), an 11-component diet quality score (score range, 0-110), with higher scores indicating a healthier diet. Main Outcome and Measures: Incident dementia ascertained through linkage to electronic health records. Results: Among 8225 participants without dementia in 1991-1993 (mean age, 50.2 years [SD, 6.1 years]; 5686 [69.1%] were men), a total of 344 cases of incident dementia were recorded during a median follow-up of 24.8 years (interquartile range, 24.2-25.1 years). No significant difference in the incidence rate for dementia was observed in tertiles of AHEI exposure during 1991-1993, 1997-1999 (median follow-up, 19.1 years), and 2002-2004 (median follow-up, 13.5 years). Compared with an incidence rate for dementia of 1.76 (95% CI, 1.47-2.12) per 1000 person-years in the worst tertile of AHEI (lowest tertile of diet quality) in 1991-1993, the absolute rate difference for the intermediate tertile was 0.03 (95% CI, -0.43 to 0.49) per 1000 person-years and for the best tertile was 0.04 (95% CI, -0.42 to 0.51) per 1000 person-years. Compared with the worst AHEI tertile in 1997-1999 (incidence rate for dementia, 2.06 [95% CI, 1.62 to 2.61] per 1000 person-years), the absolute rate difference for the intermediate AHEI tertile was 0.14 (95% CI, -0.58 to 0.86) per 1000 person-years and for the best AHEI tertile was 0.14 (95% CI, -0.58 to 0.85) per 1000 person-years. Compared with the worst AHEI tertile in 2002-2004 (incidence rate for dementia, 3.12 [95% CI, 2.49 to 3.92] per 1000 person-years), the absolute rate difference for the intermediate AHEI tertile was -0.61 (95% CI, -1.56 to 0.33) per 1000 person-years and for the best AHEI tertile was -0.73 (95% CI, -1.67 to 0.22) per 1000 person-years. In the multivariable analysis, the adjusted hazard ratios (HRs) for dementia per 1-SD (10-point) AHEI increment were not significant as assessed in 1991-1993 (adjusted HR, 0.97 [95% CI, 0.87 to 1.08]), in 1997-1999 (adjusted HR, 0.97 [95% CI, 0.83 to 1.12]), or in 2002-2004 (adjusted HR, 0.87 [95% CI, 0.75 to 1.00]). Conclusions and Relevance: In this long-term prospective cohort study, diet quality assessed during midlife was not significantly associated with subsequent risk for dementia.


Assuntos
Demência/epidemiologia , Dieta , Estudos de Coortes , Inquéritos sobre Dietas , Ingestão de Energia , Análise Fatorial , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Risco , Fatores Socioeconômicos
13.
J Hum Hypertens ; 33(9): 671-678, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30842546

RESUMO

Diet rich in fruits and vegetables (F&V) is an established protective factor for hypertension, but the available evidence regarding the impact of F&V consumption on age-related blood pressure change is limited. We examined whether systolic (SBP) and diastolic (DBP) blood pressure trajectories are influenced by F&V intakes in an ageing Russian cohort. Dietary data was available for 8997 men and women in the Health, Alcohol and Psychosocial Factors in Eastern Europe prospective cohort study. Blood pressure measurements were taken at three time-points over 12 years of follow-up, during which time the mean age of the sample changed from 58 to 69 years. The relationships between F&V intake and SBP and DBP were assessed using mixed-effect multilevel models. In the multivariable adjusted models, fruit intake was inversely related to both systolic and diastolic blood pressure at baseline (mean SBP and DBP was 3.5 mmHg and 1.4 mm Hg lower in the highest compared to the lowest intake tertiles, respectively (both p values < 0.001)). However, it was not associated with blood pressure change over time (difference in annual SBP and DBP change was 0.11 mmHg (p value = 0.138) and 0.01 mmHg (p value = 0.894), respectively). We found no significant link between vegetable intake and blood pressure, neither cross-sectionally nor longitudinally. In addition to the association with diet, we observed increasing SBP and mostly steady DBP over age, with deceleration and downward turn after the ages of 55-59 years. On the whole, this analysis found no consistent association between F&V intake and trajectories of blood pressure in older age.

14.
Alzheimers Res Ther ; 11(1): 29, 2019 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-30922415

RESUMO

OBJECTIVE: Alzheimer's disease (AD) is the sixth leading cause of death, with an average survival estimated between 5 and 10 years after diagnosis. Despite recent advances in diagnostic criteria of AD, few studies have used biomarker-based diagnostics to determine the prognostic factors of AD. We investigate predictors of death and institutionalization in a population of AD patients with high probability of AD physiopathology process assessed by positivity of three CSF biomarkers. METHODS: Three hundred twenty-one AD patients with abnormal values for CSF beta-amyloid peptide (Aß42), tau, and phosphorylated tau levels were recruited from a memory clinic-based registry between 2008 and 2017 (Lariboisiere hospital, Paris, France) and followed during a median period of 3.9 years. We used multivariable Cox models to estimate the hazard ratio (HR) of death and institutionalization for baseline clinical data, genotype of the apolipoprotein E (APOE), and levels of CSF biomarkers. RESULTS: A total of 71 (22%) patients were institutionalized and 57 (18%) died during the follow-up. Greater age, male sex, lower MMSE score, and lower CSF Aß42 level were associated with an increased risk of mortality. One standard deviation lower CSF Aß42 (135 pg/mL) was associated with a 89% increased risk of death (95% CI = 1.25-2.86; p = 0.002). This association was not modified by age, sex, education, APOE ε4, and disease severity. There was no evidence of an association of tau CSF biomarkers with mortality. None of the CSF biomarkers were associated with institutionalization. CONCLUSIONS: Lower CSF Aß42 is a strong prognostic marker of mortality in AD patients, independently of age or severity of the disease. Whether drugs targeting beta-amyloid peptide could have an effect on mortality of AD patients should be investigated in future clinical trials.

16.
PLoS One ; 14(1): e0208692, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30625153

RESUMO

PURPOSE: Accelerometers are increasingly used to obtain valuable descriptors of physical activity for health research. The cut-points approach to segment accelerometer data is widely used in physical activity research but requires resource expensive calibration studies and does not make it easy to explore the information that can be gained for a variety of raw data metrics. To address these limitations, we present a data-driven approach for segmenting and clustering the accelerometer data using unsupervised machine learning. METHODS: The data used came from five hundred fourteen-year-old participants from the Millennium cohort study who wore an accelerometer (GENEActiv) on their wrist on one weekday and one weekend day. A Hidden Semi-Markov Model (HSMM), configured to identify a maximum of ten behavioral states from five second averaged acceleration with and without addition of x, y, and z-angles, was used for segmenting and clustering of the data. A cut-points approach was used as comparison. RESULTS: Time spent in behavioral states with or without angle metrics constituted eight and five principal components to reach 95% explained variance, respectively; in comparison four components were identified with the cut-points approach. In the HSMM with acceleration and angle as input, the distributions for acceleration in the states showed similar groupings as the cut-points categories, while more variety was seen in the distribution of angles. CONCLUSION: Our unsupervised classification approach learns a construct of human behavior based on the data it observes, without the need for resource expensive calibration studies, has the ability to combine multiple data metrics, and offers a higher dimensional description of physical behavior. States are interpretable from the distributions of observations and by their duration.


Assuntos
Aprendizado de Máquina não Supervisionado , Acelerometria , Exercício/fisiologia , Humanos
17.
Environ Int ; 122: 346-356, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30503316

RESUMO

There is increasing evidence of the health benefits of exposure to natural environments, including green and blue spaces. The association with physical functioning and its decline at older age remains to be explored. The aim of the present study was to investigate the longitudinal association between the natural environment and the decline in physical functioning in older adults. We based our analyses on three follow-ups (2002-2013) of the Whitehall II study, including 5759 participants (aged 50 to 74 years at baseline) in the UK. Exposure to natural environments was assessed at each follow-up as (1) residential surrounding greenness across buffers of 500 and 1000 m around the participants' address using satellite-based indices of greenness (Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI)) and (2) the distance from home to the nearest natural environment, separately for green and blue spaces, using a land cover map. Physical functioning was characterized by walking speed, measured three times, and grip strength, measured twice. Linear mixed effects models were used to quantify the impact of green and blue space on physical functioning trajectories, controlled for relevant covariates. We found higher residential surrounding greenness (EVI and NDVI) to be associated with slower 10-year decline in walking speed. Furthermore, proximity to natural environments (green and blue spaces combined) was associated with slower decline in walking speed and grip strength. We observed stronger associations between distance to natural environments and decline in physical functioning in areas with higher compared to lower area-level deprivation. However, no association was observed with distance to green or blue spaces separately. The associations with decline in physical functioning were partially mediated by social functioning and mental health. Our results suggest that higher residential surrounding greenness and living closer to natural environments contribute to better physical functioning at older ages.


Assuntos
Envelhecimento/fisiologia , Meio Ambiente , Características de Residência , Idoso , Feminino , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade
18.
BMC Med Res Methodol ; 18(1): 89, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30157752

RESUMO

BACKGROUND: Informative attrition occurs when the reason participants drop out from a study is associated with the study outcome. Analysing data with informative attrition can bias longitudinal study inferences. Approaches exist to reduce bias when analysing longitudinal data with monotone missingness (once participants drop out they do not return). However, findings may differ when using these approaches to analyse longitudinal data with non-monotone missingness. METHODS: Different approaches to reduce bias due to informative attrition in non-monotone longitudinal data were compared. To achieve this aim, we simulated data from a Whitehall II cohort epidemiological study, which used the slope coefficients from a linear mixed effects model to investigate the association between smoking status at baseline and subsequent decline in cognition scores. Participants with lower cognitive scores were thought to be more likely to drop out. By using a simulation study, a range of scenarios using distributions of variables which exist in real data were compared. Informative attrition that would introduce a known bias to the simulated data was specified and the estimates from a mixed effects model with random intercept and slopes when fitted to: available cases; data imputed using multiple imputation (MI); imputed data adjusted using pattern mixture modelling (PMM) were compared. The two-fold fully conditional specification MI approach, previously validated for non-monotone longitudinal data under ignorable missing data assumption, was used. However, MI may not reduce bias because informative attrition is non-ignorable missing. Therefore, PMM was applied to reduce the bias, usually unknown, by adjusting the values imputed with MI by a fixed value equal to the introduced bias. RESULTS: With highly correlated repeated outcome measures, the slope coefficients from a mixed effects model were found to have least bias when fitted to available cases. However, for moderately correlated outcome measurements, the slope coefficients from fitting a mixed effects model to data adjusted using PMM were least biased but still underestimated the true coefficients. CONCLUSIONS: PMM may potentially reduce bias in studies analysing longitudinal data with suspected informative attrition and moderately correlated repeated outcome measurements. Including additional auxiliary variables in the imputation model may also reduce any remaining bias.


Assuntos
Algoritmos , Simulação por Computador , Interpretação Estatística de Dados , Modelos Teóricos , Idoso , Viés , Cognição , Estudos de Coortes , Coleta de Dados/métodos , Coleta de Dados/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , /estatística & dados numéricos , Fumantes/estatística & dados numéricos , Fumar/epidemiologia , Fumar/psicologia
19.
BMJ ; 362: k2927, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30068508

RESUMO

OBJECTIVE: To examine the association between alcohol consumption and risk of dementia. DESIGN: Prospective cohort study. SETTING: Civil service departments in London (Whitehall II study). PARTICIPANTS: 9087 participants aged 35-55 years at study inception (1985/88). MAIN OUTCOME MEASURES: Incident dementia, identified through linkage to hospital, mental health services, and mortality registers until 2017. Measures of alcohol consumption were the mean from three assessments between 1985/88 and 1991/93 (midlife), categorised as abstinence, 1-14 units/week, and >14 units/week; 17 year trajectories of alcohol consumption based on five assessments of alcohol consumption between 1985/88 and 2002/04; CAGE questionnaire for alcohol dependence assessed in 1991/93; and hospital admission for alcohol related chronic diseases between 1991 and 2017. RESULTS: 397 cases of dementia were recorded over a mean follow-up of 23 years. Abstinence in midlife was associated with a higher risk of dementia (hazard ratio 1.47, 95% confidence interval 1.15 to 1.89) compared with consumption of 1-14 units/week. Among those drinking >14 units/week, a 7 unit increase in alcohol consumption was associated with a 17% (95% confidence interval 4% to 32%) increase in risk of dementia. CAGE score >2 (hazard ratio 2.19, 1.29 to 3.71) and alcohol related hospital admission (4.28, 2.72 to 6.73) were also associated with an increased risk of dementia. Alcohol consumption trajectories from midlife to early old age showed long term abstinence (1.74, 1.31 to 2.30), decrease in consumption (1.55, 1.08 to 2.22), and long term consumption >14 units/week (1.40, 1.02 to 1.93) to be associated with a higher risk of dementia compared with long term consumption of 1-14 units/week. Analysis using multistate models suggested that the excess risk of dementia associated with abstinence in midlife was partly explained by cardiometabolic disease over the follow-up as the hazard ratio of dementia in abstainers without cardiometabolic disease was 1.33 (0.88 to 2.02) compared with 1.47 (1.15 to 1.89) in the entire population. CONCLUSION: The risk of dementia was increased in people who abstained from alcohol in midlife or consumed >14 units/week. In several countries, guidelines define thresholds for harmful alcohol consumption much higher than 14 units/week. The present findings encourage the downward revision of such guidelines to promote cognitive health at older ages.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Demência/epidemiologia , Adulto , Idoso , Transtornos Relacionados ao Uso de Álcool/epidemiologia , Feminino , Seguimentos , Humanos , Londres/epidemiologia , Estudos Longitudinais , Masculino , Serviços de Saúde Mental , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
20.
Eur Heart J ; 39(33): 3119-3125, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29901708

RESUMO

Aims: To examine associations of diastolic and systolic blood pressure (SBP) at age 50, 60, and 70 years with incidence of dementia, and whether cardiovascular disease (CVD) over the follow-up mediates this association. Methods and results: Systolic and diastolic blood pressure were measured on 8639 persons (32.5% women) from the Whitehall II cohort study in 1985, 1991, 1997, and 2003. Incidence of dementia (n dementia/n total = 385/8639) was ascertained from electronic health records followed-up until 2017. Cubic splines using continuous blood pressure measures suggested SBP ≥130 mmHg at age 50 but not at age 60 or 70 was associated with increased risk of dementia, confirmed in Cox regression analyses adjusted for sociodemographic factors, health behaviours, and time varying chronic conditions [hazard ratio (HR) 1.38; 95% confidence interval (95% CI) 1.11, 1.70]. Diastolic blood pressure was not associated with dementia. Participants with longer exposure to hypertension (SBP ≥ 130 mmHg) between mean ages of 45 and 61 years had an increased risk of dementia compared to those with no or low exposure to hypertension (HR 1.29, 95% CI 1.00, 1.66). In multi-state models, SBP ≥ 130 mmHg at 50 years of age was associated with greater risk of dementia in those free of CVD over the follow-up (HR 1.47, 95% CI 1.15, 1.87). Conclusion: Systolic blood pressure ≥130 mmHg at age 50, below the conventional ≥140 mmHg threshold used to define hypertension, is associated with increased risk of dementia; in these persons this excess risk is independent of CVD.


Assuntos
Pressão Sanguínea/fisiologia , Demência/etiologia , Hipertensão/psicologia , Fatores Etários , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/psicologia , Estudos de Coortes , Demência/epidemiologia , Demência/fisiopatologia , Inglaterra/epidemiologia , Feminino , Seguimentos , Comportamentos Relacionados com a Saúde , Humanos , Hipertensão/epidemiologia , Hipertensão/fisiopatologia , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sístole/fisiologia
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