Sleep disturbances and later cognitive status: a multi-centre study

OBJECTIVE

To investigate the associations between sleep disturbances in mid-life and late-life and late-life cognitive status.

METHODS

In four population-based studies (three Swedish studies: H70 study, Kungsholmen Project (KP) and The Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD); and one Finnish study: Cardiovascular Risk Factors, Aging and Dementia (CAIDE)), participants provided self-reports on insomnia, nightmares and general sleep problems. Late-life cognitive status was measured by the Mini Mental State Exam (MMSE). The associations between late-life sleep disturbances and cognition 3-11 years later were investigated across all studies (n = 3210). Mean baseline ages were 70 (CAIDE, H70 and SWEOLD), and 84 years (KP). Additional analyses examined the association between midlife sleep and late-life cognition using CAIDE (21 and 31 years follow-up, n = 1306, mean age 50 years), and SWEOLD (20-24 years follow-up, n = 2068, mean age 58 years). Ordered logistic regressions, adjusted for potential baseline confounders, were used in the analyses.

RESULTS

Late-life sleep disturbances were associated with poorer cognition after 3-11 years (fully adjusted β = -0.12, 95% CI = -0.24 to -0.01). Midlife nightmares and insomnia were also associated with lower MMSE scores (fully adjusted β = -0.28, 95% CI = -0.49 to -0.07 and β = -0.20, 95% CI = -0.39 to -0.01), although the latter association was attenuated after adjusting for lifestyle/health-related confounders. Midlife general sleep problems were not associated with late-life MMSE performance.

CONCLUSIONS

Sleep disturbances and midlife nightmares were associated with lower MMSE scores, which suggests that sleep disturbances in earlier life stages can be associated with worse late-life cognition.

Midlife Work-Related Stress Increases Dementia Risk in Later Life: The CAIDE 30-Year Study

Objective

To investigate the associations between midlife work-related stress and mild cognitive impairment (MCI), dementia, and Alzheimer's disease later in life, in a large representative population.

Method

Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study participants were randomly selected from independent population-based surveys (mean age 50 years). A random sample of 2,000 individuals was invited for two reexaminations including cognitive tests (at mean age 71 and mean age 78), and 1,511 subjects participated in at least one reexamination (mean follow-up 28.5 years). Work-related stress was measured using two questions on work demands that were administered in midlife. Analyses adjusted for important confounders.

Results

Higher levels of midlife work-related stress were associated with higher risk of MCI (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.08-1.76), dementia (OR, 1.53; CI, 1.13-2.07), and Alzheimer's disease (OR, 1.55; CI, 1.19-2.36) at the first follow-up among the CAIDE participants. Results remained significant after adjusting for several possible confounders. Work-related stress was not associated with MCI and dementia during the extended follow-up.

Discussion

Midlife work-related stress increases the risk for MCI, dementia, and Alzheimer's disease in later life. The association was not seen after the extended follow-up possibly reflecting selective survival/participation, heterogeneity in dementia among the oldest old, and a critical time window for the effects of midlife stress.

Self-rated physical fitness and estimated maximal oxygen uptake in relation to all-cause and cause-specific mortality

This study investigated the longitudinal associations of self-rated physical fitness and estimated maximal oxygen uptake (VO2max) with all-cause and cause-specific mortality. A total of 59 741 participants in the Finnish National FINRISK Study Cohort had data on self-rated physical fitness and covariates. A subsample of 4823 participants had estimated VO2max data. Follow-up ranged from 3 to 38 years. Associations of self-rated physical fitness and VO2max with mortality were analyzed using multivariate Cox proportional hazard models. The study showed that poor self-rated physical fitness was related to all-cause mortality (hazard ratio [HR] 1.9; 95% confidence interval [CI] 1.8-2.0) and mortality due to cardiovascular (HR 2.0, 95% CI 1.9-2.2), cerebrovascular (HR 1.9, 95% CI 1.6-2.2) and respiratory diseases (HR 2.1, 95% CI 1.9-2.4), trauma (HR 1.7, 95% CI 1.3-2.0), infections (HR 1.8, 95% CI 1.3-2.7), dementia (HR 1.9, 95% CI 1.6-2.3), and cancer (HR 1.7, 95% CI 1.5-1.9). Coexisting higher age, physical inactivity, male gender, and severe chronic conditions further increased the risk. In men, higher VO2max was associated with a lower risk of lung cancer mortality (HR 0.8, 95% CI 0.7-0.96). Based on the results, self-rated physical fitness reflects a combination of unfavorable biological and lifestyle-related factors, which increase mortality risk. A simple question about perceived physical fitness may reveal at-risk individuals who would benefit from more intensive treatment of chronic conditions and other interventions aiming to promote better fitness and well-being.

Midlife work ability and mobility limitation in old age among non-disability and disability retirees--a prospective study

Background

Little is known about the wellbeing and mobility limitation of older disability retirees. Personal and environmental factors, such as time spent in working life, may either exacerbate or mitigate the onset of mobility limitation in general population.

We aimed to study perceived midlife work ability as a determinant of self-reported mobility limitation in old age among municipal employees who transitioned into non-disability and disability retirement.

Methods

4329 participants of the Finnish Longitudinal Study of Municipal Employees (FLAME) had retired during January 1985 and July 2000. They had data on retirement, perceived work ability in 1985, and self-reported mobility limitation (non-disability retirement n = 2870, men 39 %; and diagnose-specific disability retirement n = 1459, men 48 %). Self-reported mobility was measured in 1985, 1992, 1997 and 2009. The latest score available was used to assess the number of mobility limitation. Work ability was measured by asking the respondents to evaluate their current work ability against their lifetime best in 1985. Incidence rate ratios (IRRs) and 95 % confidence intervals (CIs) for work ability predicting mobility limitation in non-disability and diagnose-specific disability retirement groups were calculated using Poisson regression models.

Results

The prevalence of mobility limitation for those who transitioned into non-disability retirement (Incidence Rate, IR = 0.45, 95 % CI = 0.44–0.46) was lower compared to those who retired due to disability (IR = 0.65, CI = 0.63–0.66). A one-point increase in the work ability score decreased the risk for having one more mobility limitation among non-disability and all diagnose-specific retirement groups (musculoskeletal disease, cardiovascular disease, mental disorder, and other diseases).

Conclusions

Better midlife work ability may protect from old age mobility limitation among those who retire due to non-disability and disability. Promoting work ability in midlife may lead to more independent, active aging, regardless of type of retirement.

Type of retirement as a determinant of pre- and post-retirement hospital in-patient care use: a prospective study

BACKGROUND

We examined prospectively the use of all-cause hospital in-patient care among public sector employees by using a 3-year pre- and post-retirement study window.

METHODS

A total of 5269 participants of the Finnish Longitudinal Study of Municipal Employees had retired during January 1984 and July 2000. They had register-based data on retirement (non-disability retirement n = 3411, men 40%, and diagnose-specific disability retirement n = 1858, men 50%) and all-cause hospital in-patient admissions and discharges. Analyses were conducted using Generalized Estimating Equation model.

RESULTS

The prevalence of hospital care use for non-disability retirees remained stable during the 6-year study window. The rate ratio (RR) for hospital care use increased in the year prior to retirement for men and women who transitioned into disability retirement due to cardiovascular disease and for women with disability due to mental disease. The RRs for hospital care use in the post-retirement year decreased for men who retired due to cardiovascular disease or mental disorders and for women who retired due to cardiovascular or musculoskeletal diseases.

CONCLUSIONS

An increase in hospital care preceding retirement in major diagnosis-specific disability retirement groups was followed by various patterns of decrease in the need of care indicated a beneficial health effect of retirement.

Work-related stress in midlife is associated with higher number of mobility limitation in older age-results from the FLAME study

The aim of this study is to investigate whether work-related stress symptoms in midlife are associated with a number of mobility limitations during three decades from midlife to late life. Data for the study come from the Finnish Longitudinal Study of Municipal Employees (FLAME). The study includes a total of 5429 public sector employees aged 44-58 years at baseline who had information available on work-related stress symptoms in 1981 and 1985 and mobility limitation score during the subsequent 28-year follow-up. Four midlife work-related stress profiles were identified: negative reactions to work and depressiveness, perceived decrease in cognition, sleep disturbances, and somatic symptoms. People with a high number of stress symptoms in 1981 and 1985 were categorized as having constant stress. The number of self-reported mobility limitations was computed based on an eight-item list of mobility tasks presented to the participants in 1992, 1997, and 2009. Data were analyzed using joint Poisson regression models. The study showed that depending on the stress profile, persons suffering from constant stress in midlife had a higher risk of 30-70 % for having one more mobility limitation during the following 28 years compared to persons without stress after adjusting for mortality, several lifestyle factors, and chronic conditions. A less pronounced risk increase (20-40 %) was observed for persons with occasional symptoms. The study suggests that effective interventions aiming to reduce work-related stress should focus on both primary and secondary prevention.

Association between mid- to late life physical fitness and dementia: evidence from the CAIDE study

OBJECTIVES

This study investigated the association between perceived physical fitness at midlife, changes in perceived fitness during the three decades from mid- to late life and dementia risk.

DESIGN

Prospective cohort study.

SETTING

Cardiovascular risk factors, ageing and incidence of dementia (CAIDE) study.

SUBJECTS

Subjects were selected from four independent, random samples of population-based cardiovascular surveys and were first examined in 1972, 1977, 1982 or 1987, when they were on average 50 years old. The CAIDE target population included 3559 individuals. A random sample of 2000 individuals still alive in 1997 was drawn for re-examinations (performed in 1998 and 2005-2008) that consisted of cognitive assessments, with 1511 subjects participating in at least one re-examination. Dementia diagnoses were also confirmed from national registers for the entire target population.

MAIN OUTCOME MEASURE

All-cause dementia.

RESULTS

Poor physical fitness at midlife was associated with increased dementia risk in the entire target population [hazard ratio (HR), 1.5; 95% confidence interval (CI), 1.1-2.0]. In participants, odds ratio (OR) was 2.0 (95% CI, 0.9-4.0). This association was significant in apolipoprotein E ε4 allele (APOEε4) noncarriers (OR, 4.3; 95% CI, 1.4-13.3), men (HR, 1.8; 95% CI, 1.1-3.0) and people with chronic conditions (HR, 2.9; 95% CI, 1.3-6.6). A decline in fitness after midlife was also associated with dementia (OR, 3.0; 95% CI, 1.7-5.1), which was significant amongst both men and women and more pronounced in APOEε4 carriers (OR, 4.4; 95% CI, 2.1-9.1).

CONCLUSIONS

Perceived poor physical fitness reflects a combination of biological and lifestyle-related factors that can increase dementia risk. A simple question about perceived physical fitness may reveal at-risk individuals who could benefit from preventive interventions.

Job strain in the public sector and hospital in-patient care use in old age: a 28-year prospective follow-up

BACKGROUND

high job strain increases the risk of health decline, but little is known about the specific consequences and long-term effects of job strain on old age health.

OBJECTIVES

purpose was to investigate whether physical and mental job strain in midlife was associated with hospital care use in old age.

METHODS

study population included 5,625 Finnish public sector employees aged 44-58 years who worked in blue- and white-collar professions in 1981. The number of in-patient hospital care days was collected from the Finnish Hospital Discharge Register for the 28-year follow-up period.

RESULTS

rates of hospital care days per 1,000 person-years for men were 7.78 (95% confidence interval [CI] 7.71-7.84) for low, 9.68 (95% CI 9.50-9.74) for intermediate and 12.56 (95% CI 12.47-12.66) for high physical job strain in midlife. The corresponding rates for women were 6.63 (95% CI 6.57-6.68), 7.91 (95% CI 7.87-7.95) and 10.35 (95% CI 10.25-10.42), respectively. Rates were parallel but lower for mental job strain. Reporting high physical job strain in midlife increased the risk of hospital care in old age compared with those who reported low job strain, fully adjusted incidence rate ratio 1.17 (95% CI 1.00-1.38) for men and 1.42 (95% CI 1.25-1.61) for women. These associations were robust in analyses confined to hospital care that took place after the employees had turned 65 years.

CONCLUSION

exposure to high mental and, particularly, high physical job strain in midlife may set employees on a higher healthcare use trajectory which persists into old age.

Inverse effects of midlife occupational and leisure time physical activity on mobility limitation in old age--a 28-year prospective follow-up study

OBJECTIVES

To evaluate in a sample of initially middle-aged municipal employees whether leisure time (LPA) or occupational physical activity (OPA) was associated with mobility limitation (ML) in old age.

DESIGN

Prospective population-based follow-up.

SETTING

Municipalities in Finland.

PARTICIPANTS

Public sector employees from the Finnish Longitudinal Study on Municipal Employees (FLAME) initially aged 44 to 58 (N = 5,200).

MEASUREMENTS

Baseline data were collected in 1981, including LPA (average exercise within previous year: inactive (no exercise), moderate (some form of exercise ≤ 1 time per week), vigorous (brisk exercise ≥ 1 time per week)) and OPA (usual activities at work within previous year: light (light work sitting, standing, or moving around), moderate (moderate work moving around), vigorous (heavy physical work)). Number of MLs was assessed using a questionnaire (8 items) in 1985, 1992, 1997, and 2009; the latest mobility score available for each subject was used for analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for LPA and OPA predicting ML were estimated in a joint Poisson regression model adjusted for survival data; the other type of PA; and sociodemographic, socioeconomic, and health-related factors.

RESULTS

Mean age at baseline was 50.3 ± 3.6; 56.9% of participants were female. Participants with vigorous OPA in midlife had greater risk of a unit increase in ML in old age than those with light OPA (fully adjusted IRR = 1.09, 95% CI = 1.03-1.16). Participants with vigorous LPA had lower risk of ML than inactive participants (fully adjusted IRR = 0.81, 95% CI = 0.76-0.86).

CONCLUSION

Findings suggest that LPA and OPA in midlife have independent, inverse effects on mobility in old age in terms of a harmful effect of vigorous OPA and a protective effect of vigorous LPA.

Leisure-time physical activity from mid- to late life, body mass index, and risk of dementia

BACKGROUND

Physical activity may be beneficial for cognition, but the effect may vary depending on personal characteristics.

METHODS

We investigated the associations between leisure-time physical activity (LTPA) from mid- to late life, the risk of dementia, and the role of body mass index, sex, and APOE in the CAIDE study during 28-year follow-up. Cognitive function of a random subsample was assessed at a mean age of 78.8 years (n = 1511), and dementia/Alzheimer's disease (AD) diagnoses were identified from national registers for the entire target population (n = 3559).

RESULTS

Moderate (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.08-1.99) and low levels of midlife LTPA (HR, 1.39; 95% CI, 0.99-1.95) were associated with higher risk of dementia in comparison with the most active category. The benefits were more pronounced among men, overweight individuals, and APOE ε4 noncarriers. Maintaining high LTPA (HR, 0.16; 95% CI, 0.06-0.41) or increasing LTPA (HR, 0.19; 95% CI, 0.09-0.40) after midlife was associated with lower dementia risk. Similar results were observed for AD.

CONCLUSIONS

The window of opportunity for preventive physical activity interventions may extend from midlife to older ages.

Accumulation of sensory difficulties predicts fear of falling in older women

OBJECTIVE

To explore whether the accumulation of sensory difficulties predicts fear of falling (FOF), and whether the traits correlate with each other regardless of familial factors.

METHODS

Self-reported hearing, vision and balance difficulties, and FOF were assessed using structured questionnaires at the baseline and after a 3-year follow-up in 63- to 76-year-old women (n = 434).

RESULTS

Among the women without FOF at baseline (n = 245), 41% reported FOF at follow-up. Increasing numbers of sensory difficulties at baseline predicted higher incidence of FOF. The relationship between accumulated sensory difficulties and FOF was not mediated by familial factors.

DISCUSSION

The accumulation of multiple sensory difficulties may hinder older people from receiving compensatory information about body position and environment, thus jeopardizing a person's confidence in maintaining a balanced position. Regular screening of sensory functions followed by appropriate actions may prevent the development of FOF, and thus contribute to prevention of falls and promotion of healthy aging.

Perceived stress symptoms in midlife predict disability in old age: a 28-year prospective cohort study

BACKGROUND

Stress has damaging effects on individual's health. However, information about the long-term consequences of mental stress is scarce.

METHODS

This 28-year prospective cohort study examined on the associations between midlife stress and old age disability among 2,994 Finnish municipal professionals aged 44-58 years at baseline. Self-reported stress symptoms were assessed at baseline in 1981 and 4 years later in 1985 and perceived disability in 2009. For the baseline data, principal component analysis was used for differentiation into stress symptom profiles. The regression coefficient estimates for self-care disability (activities of daily living) and instrumental activities of daily living disability were estimated using left-censored regression. The odds ratios for mobility limitation were estimated using logistic regression.

RESULTS

Four midlife stress profiles were identified: negative reactions to work and depressiveness, perceived decrease in cognition, sleep disturbances, and somatic symptoms. We saw a clear gradient of increasing disability severity in old age for increasing intensity of midlife stress symptoms. In comparison with the participants with no stress symptoms, the extensively adjusted left-censored and logistic regression models showed that in old age, disability scores were almost 2-4 units higher and risk for mobility limitation was 2-3 times higher for those with constant stress symptoms in midlife.

CONCLUSIONS

Among occupationally active 44- to 58-year-old men and women, perceived stress symptoms in midlife correlated with disability 28 years later. Stress symptoms may be the first signs of decompensation of individual functioning relative to environmental demands, which may later manifest in disabilities.

Radiation dose estimation in computed tomography examinations using NRPB-SR250 software in aretrospective analysis of a patient population

Computed tomography (CT) imaging contributes to a major part of medical radiation exposure. With regard to patients safety, frequent CT examinations (CTEs) performed on the same patient are of particular concern. Tools for tracking the individual patient radiation exposure history and cumulative dose assessment may become important. Here, the applicability of the NRPB-SR250 software was assessed in a retrospective analysis of radiation doses from CTE made consecutively in male patients. Most of the examinations focused on the abdomen or the whole body. The mean number of CTs per patient was 6.8. Significant cumulative effective doses were observed: 76 (66 %) patients received an effective dose higher than 50 mSv, while the maximum was ∼280 mSv. A more than 3-fold effective dose difference was observed between scanners, depending on the scanning protocols. The NRPB-SR250 software proved to be a robust tool for the assessment of organ doses and the effective radiation dose from CT, while challenges were encountered in finding the precise imaging data in retrospective protocols.

Vision in relation to lower extremity deficit in older women: cross-sectional and longitudinal study

BACKGROUND AND AIMS

Vision problems are common experiences within the older population. This study aimed to examine the association between vision and lower extremity impairment.

METHODS

434 women aged 63-75 participated in visual acuity (VA) measurements at baseline and 313 persons at three-year follow-up. Measurements of lower extremity function included maximal isometric knee extension strength, leg extension power, maximal walking speed and standing balance.

RESULTS

At baseline, knee extension strength was lower among participants with visual impairment (VI) (273.2±6.4 N) compared to those with good vision (306.5±5.9 N, p<0.001) as well as leg extension power (95.2±2.7 W vs 104.2±2.6 W, p=0.009) and maximal walking speed (1.6±0.02 m/s vs 1.8±0.03 m/s, p<0.001). Higher velocity moment among persons with VI (53.5±2.7 mm²/s vs 42.7±1.4 mm²/s, p<0.001) indicated that persons with VI had poorer balance compared to persons with good vision. Decreased isometric knee extension strength (OR 1.26, 95% CI 1.09-1.45), poorer standing balance (OR 1.16, 95% CI 1.00-1.35) as well as lower maximal walking speed (OR 1.34, 95% CI 1.13-1.59) were associated with VI in the logistic regression models. Additionally, the association between poorer leg extension power and VI (OR 1.14, 95% CI 0.99-1.31) was of borderline statistical significance. In longitudinal analyses, VI did not predict decline in lower extremity function.

CONCLUSIONS

Lower extremity impairment was associated with VI among relatively healthy older women. However, change in lower extremity function was quite similar between the vision groups. It is possible that decreased VA may be a marker of underlying systemic factors or the aging process, which lead to poorer functional capacity, or there may be shared background factors, which lead to decreased vision and lower extremity impairment.