Validity and Reliability of Self-Assessed Physical Fitness Using Visual Analogue Scales

To test the validity and reliability of self-assessed physical fitness samples included healthcare assistants working at a hospital (women = 170, men = 17), persons working with physically and mentally handicapped patients (women = 530, men = 123), and two separate groups of healthcare students (a) women = 91 and men = 5 and (b) women = 159 and men =10. Five components of physical fitness were self-assessed by Visual Analogue Scales with illustrations and verbal anchors for the extremes: aerobic fitness, muscle strength, endurance, flexibility, and balance. Convergent and divergent validity were evaluated by age-adjusted correlations stratified by sex with performance-based measures of physical fitness. Self-assessed aerobic fitness ( r = .36–.64) (women/men), muscle strength ( r = .30–.51), and flexibility ( r = .36–.31) showed moderate convergent validity. The divergent validity was satisfactory except for flexibility among men. The reliability was moderate to good ( ICC = .62–.80). Self-assessed aerobic fitness, muscle strength, and flexibility showed moderate construct validity and moderate to good reliability using visual analogues.

The Most Important Activity and the Reasons for That Experience Reported by a Danish Population at Age 75 Years

The aim of the study was to describe the activities that 75-year-old men and women indicate as most important and to reveal why they find them important.

The data were derived from a cross-sectional study of 748 Danish 75-year-old men and women, born in 1914. The people were interviewed at home by means of a questionnaire. The most important activity was revealed by an open-ended question: what is your most important activity? The answers were classified into three qualities: type, site and social relations. The participants were asked if the activity was important because it gave enjoyment, self-confidence, challenges, company, cooperation, usefulness, new skills and/or new experiences.

A majority of the participants reported physical and individual activities as the most important and the reasons given by most participants for stating their activity as most important were work enjoyment and usefulness. It was concluded that attention should be paid to older people's possibilities for having important activities.

Development in self-rated health among older people as determinant of social relations

Aim: The purpose of this study was to analyse whether development in self-rated health (SRH) over four years was associated with the structure of and satisfaction with social relations, at four and eight years follow-up, among elderly women and men. Methods: A longitudinal questionnaire-based study was undertaken of non-institutionalized Danes, aged 70 - 95 years, with baseline in 1986. The response rate at baseline was 69%, n=1,231. First follow-up was carried out in 1990, with 91% of eligible individuals participating (n=911). Second follow-up took place in 1994, where 83% of eligible individuals participated (n=542). The association was studied between development in SRH from 1986 to 1990 and social relations in 1990 and in 1994. Results: A sustained poor SRH predicted low contact frequency OR=1.7 (1.1 - 2.6), small contact diversity OR=1.6 (1.0 - 2.6) and low contact satisfaction OR=3.4 (2.3 - 5.2) in the two-point analyses. Furthermore, a deterioration in SRH predicted poor contact satisfaction OR=2.8 (1.7 - 4.5). All analyses were adjusted for age, gender, mental health, functional ability, cohabitation status, and a measure of social relations at baseline. Results for the three-point analyses were similar to those for the two-point analyses. The associations were weaker for contact satisfaction OR=2.8 (1.7 - 4.7), but stronger for contact frequency OR=2.5 (1.4 - 4.4) and diversity OR=2.1 (1.2 - 3.6). Conclusion: Sustained poor SRH and, to some degree, deterioration in SRH were predictors of poor social relations after four and eight years.

Randomized intervention trial on preventive home visits to older people: Baseline and follow-up characteristics of participants and non-participants

Aims: In controlled intervention studies, a selective non-response or refusal to participate at baseline may bias measurable effects of the intervention. The aim of this study was to compare mortality and nursing home admission among older persons who accepted (participants) and older person who declined (non-participants) to join a controlled feasibility trial, and to describe and evaluate defined subgroups of non-participants. Methods: Prospective controlled three-year intervention study (1999—2001) in 34 Danish municipalities with five-year follow-up. Randomization and intervention (education of municipality employees) was done at municipality level. In total 5,788 home-dwelling 75- and 80-year-olds living in these municipalities were invited to participate in the study. Written consent was obtained from 4,060 persons (participation rate 71%). Results: During five-year follow-up non-participants had a higher mortality rate (survival analysis risk ratio RR=1.5, 95% CI=1.3—1.7, p<0.0001) and a higher rate of nursing home admissions (RR=1.7, 95% CI=1.3— 2.1, p<0.0001) compared with participants. Subgroups of non-participants describing themselves as ``too ill'' and persons ``not reached'' had a significantly higher mortality rate and risk of admission to nursing home than participants, whereas the subgroups of non-participants describing themselves as ``too healthy'' and having ``another reason for refusal'' did not differ from the participants. There was no difference in mortality rates between non-participants living in intervention municipalities compared with non-participants living in control municipalities. Conclusions: Mortality and nursing home admissions were higher among non-participants. Selection participation bias was of no clinical importance since subgroups of non-participants eligible for the intervention did not differ from the participants.

Socioeconomic position and smoking behaviour in Danish adults

Aims: The associations between smoking and various socioeconomic indicators may have different implications and causes, which may also vary according to sex and birth cohort. This study analyses how two dimensions of socioeconomic position, an individual ( education) and a structural ( occupation) indicator, are associated with ever, current and ex-smoking. Methods: Data on smoking behaviour were collected in five cross-sectional surveys of random samples of the general Danish population aged 20 years or more at intervals between 1982 and 1994. In total, 8,054 men and 8,281 women participated. Logistic regression was used to analyse the infl uence of education and occupation on smoking behaviour controlling for sex and birth cohort. Results: In cohorts born after 1930 ever and current smoking were related to years of school education and current occupation. The prevalences of ever and current smoking were highest among the least educated, unskilled workers, unemployed persons and persons who received welfare benefits. A significant interaction between birth cohort and education indicated that the educational difference in ever and current smoking increased significantly with increasing year of birth. In multivariate analysis controlling for sex and birth cohort, ex-smoking seemed to be more strongly associated with education than occupation .Those with 12 or more years of school education had twice as high a chance of being ex-smokers as those with 7 years of school or less. Conclusion: Smoking behaviour is strongly associated with both individual and structural indicators of socioeconomic position in Danish adults in all cohorts except for those born before 1930.

The cumulative effect of smoking at age 50, 60, and 70 on functional ability at age 75

Aims: As elderly people form a steadily growing part of the population in most parts of the world we are in need of knowledge of the influence of modifiable lifestyle factors on functional ability late in life. This study aims to examine the cumulative impact of smoking from age 50 to 70 on functional ability at age 75. Methods: 387 men and women born in 1914 and living in seven municipalities in the western part of the County of Copenhagen were followed for 25 years with examinations in 1964, 1974, 1984, and 1989. Associations between smoking and functional ability were examined using multiple logistic regression analyses with cumulative smoking as determinant and physical activity, sex, basic school education, and household composition as possible confounders. Results: There is an adverse relation between smoking and functional ability regardless of the time of examination or the ways of accumulating the smoking habits over the examinations. Cumulated former smokers have a larger risk of having reduced functional ability at age 75 (OR: 1.35 (1.13 - 1.61)) compared with never smokers. The odds ratios of reduced functional ability were 2.46 (1.44 - 4.17) among cumulated smokers of 1 - 14 grams of tobacco/day and 3.32 (1.63 - 6.72) among smokers of more than 14 grams of tobacco/ day. Conclusions: The findings in this study stress the importance of continuing and strengthening efforts to reduce the prevalence of smokers in the population. Furthermore the results indicate that even after the 50th birthday it is possible to gain a healthier old age by abstaining from smoking.

Melatonin and cortisol profiles in late midlife and their association with age-related changes in cognition

Previous studies have reported an association between circadian disturbances and age-related cognitive impairment. The aim was to study the 24-hour profiles of melatonin and cortisol in relation to cognitive function in middle-aged male subjects. Fifty healthy middle-aged males born in 1953 were recruited from a population-based cohort based on previous cognitive assessments in young adulthood and late midlife. The sample included 24 cognitively high-functioning and 26 cognitively impaired participants. Saliva samples were collected every 4 hours over a 24-hour period and analyzed for cortisol and melatonin levels by immunoassay. All participants exhibited clear circadian rhythms of salivary melatonin and cortisol. Salivary melatonin concentrations had a nocturnal peak at approximately 4 am. The median nocturnal melatonin response at 4 am was significantly lower in the cognitively impaired group than in the high-functioning group (-4.6 pg/mL, 95% CI: -7.84, -1.36, P=0.006). The 24-hour mean melatonin concentration (high-functioning group: 4.80±0.70 pg/mL, vs cognitively impaired group: 4.81±0.76 pg/mL; P>0.05) (or the area under the curve, AUC) was not significantly different between the two groups. Cortisol levels were low during the night, and peaked at approximately 8 am. Median cortisol concentrations were similar at all times, as were the 24-hour mean cortisol concentrations and AUC. To the best of our knowledge, ours is the first study to assess circadian measures (ie, melatonin and cortisol) in healthy middle-aged men with different cognitive trajectories in midlife. We found evidence of altered circadian rhythms with a reduced nocturnal melatonin response at 4 am in men with cognitive impairment. The 24-hour concentration and AUC of melatonin and cortisol were similar in the cognitively high-functioning group and in the cognitively impaired.

Does physical exposure throughout working life influence chair-rise performance in midlife? A retrospective cohort study of associations between work and physical function in Denmark

OBJECTIVES

Our aim was to study associations between physical exposures throughout working life and physical function measured as chair-rise performance in midlife.

METHODS

The Copenhagen Aging and Midlife Biobank (CAMB) provided data about employment and measures of physical function. Individual job histories were assigned exposures from a job exposure matrix. Exposures were standardised to ton-years (lifting 1000 kg each day in 1 year), stand-years (standing/walking for 6 h each day in 1 year) and kneel-years (kneeling for 1 h each day in 1 year). The associations between exposure-years and chair-rise performance (number of chair-rises in 30 s) were analysed in multivariate linear and non-linear regression models adjusted for covariates.

RESULTS

Mean age among the 5095 participants was 59 years in both genders, and, on average, men achieved 21.58 (SD=5.60) and women 20.38 (SD=5.33) chair-rises in 30 s. Physical exposures were associated with poorer chair-rise performance in both men and women, however, only associations between lifting and standing/walking and chair-rise remained statistically significant among men in the final model. Spline regression analyses showed non-linear associations and confirmed the findings.

CONCLUSIONS

Higher physical exposure throughout working life is associated with slightly poorer chair-rise performance. The associations between exposure and outcome were non-linear.

Associations of subjective vitality with DNA damage, cardiovascular risk factors and physical performance

AIM

To examine associations of DNA damage, cardiovascular risk factors and physical performance with vitality, in middle-aged men. We also sought to elucidate underlying factors of physical performance by comparing physical performance parameters to DNA damage parameters and cardiovascular risk factors.

METHODS

We studied 2487 participants from the Metropolit cohort of 11 532 men born in 1953 in the Copenhagen Metropolitan area. The vitality level was estimated using the SF-36 vitality scale. Cardiovascular risk factors were determined by body mass index (BMI), and haematological biochemistry tests obtained from non-fasting participants. DNA damage parameters were measured in peripheral blood mononuclear cells (PBMCs) from as many participants as possible from a representative subset of 207 participants.

RESULTS

Vitality was inversely associated with spontaneous DNA breaks (measured by comet assay) (P = 0.046) and BMI (P = 0.002), and positively associated with all of the physical performance parameters (all P < 0.001). Also, we found several associations between physical performance parameters and cardiovascular risk factors. In addition, the load of short telomeres was inversely associated with maximum jump force (P = 0.018), with lowered significance after exclusion of either arthritis sufferers (P = 0.035) or smokers (P = 0.031).

CONCLUSION

Here, we show that self-reported vitality is associated with DNA breaks, BMI and objective (measured) physical performance in a cohort of middle-aged men. Several other associations in this study verify clinical observations in medical practice. In addition, the load of short telomeres may be linked to peak performance in certain musculoskeletal activities.

Frailty and depression in older adults: a high-risk clinical population

OBJECTIVE

To identify salient characteristics of frailty that increase risk of death in depressed elders.

METHODS

Data were from the Nordic Research on Ageing Study from research sites in Denmark, Sweden, and Finland. Participants were 1,027 adults aged 75 years (436 men and 591 women). Time of death was obtained, providing a maximum survival time of 11.08 years (initial evaluation took place between 1988 and 1991).

RESULTS

Depressed elders showed greater baseline impairments in each frailty characteristic (gait speed, grip strength, physical activity levels, and fatigue). Simultaneous models including all four frailty characteristics showed slow gait speed (hazard ratio: 1.84; 95% confidence interval: 1.05-3.21) and fatigue (hazard ratio: 1.94; 95% confidence interval: 1.11-3.40) associated with faster progression to death in depressed women; none of the frailty characteristics in the simultaneous model was associated with death in depressed men. In women, the effect of impaired gait speed on mortality rates nearly doubled when depression was present (nondepressed women: no gait impairment = 26%; slow gait = 40%; depressed women: no gait impairment = 32%; slow gait = 58%). A similar pattern was observed for fatigue.

CONCLUSION

The confluence of specific characteristics of frailty (fatigue and slow gait speed) and depressive illness is associated with an increased risk of death in older adults; this association is particularly strong in older depressed women. Future research should investigate whether multimodal interventions targeting depressive illness, mobility deficits, and fatigue can decrease mortality and improve quality of life in older depressed individuals with characteristics of the syndrome of frailty.

Leisure activity associated with cognitive ability level, but not cognitive change

Although activity participation is promoted as cognitively protective, critical questions of causality remain. In a cohort followed every 5 years from age 75 to 85 years, potential reciprocal associations between level and change in leisure activity participation and level and change in cognitive abilities were examined. Participants in the Glostrup 1914 Cohort, a longitudinal study of aging, completed standardized cognitive ability tests and reported their leisure activity participation (11 activities defined a leisure activity score) at ages 75, 80, and 85. Higher leisure activity was associated with higher cognitive ability (significant correlations ranged from 0.15 to 0.31, p < 0.05). Between ages 75 and 85, participation in leisure activities and cognitive ability declined significantly. Growth curve models, which provided latent variables for level of and 10-year change in both leisure activity and cognitive ability, confirmed the positive association between levels of leisure activity and cognitive ability (path coefficient = 0.36, p < 0.001); however, neither leisure activity level nor change in leisure activity were associated with cognitive change. Although a positive association between leisure activity and cognitive ability was reported—the likely precedents of this are discussed—there was no evidence that a higher level or maintenance of leisure activity was protective against cognitive decline across a 10-year follow-up.

Relationships between human vitality and mitochondrial respiratory parameters, reactive oxygen species production and dNTP levels in peripheral blood mononuclear cells

Low vitality (a component of fatigue) in middle-aged and older adults is an important complaint often identified as a symptom of a disease state or side effect of a treatment. No studies to date have investigated the potential link between dysfunctional mitochondrial ATP production and low vitality. Therefore, we measured a number of cellular parameters related to mitochondrial activity in peripheral blood mononuclear cells (PBMCs) isolated from middle-aged men, and tested for association with vitality. These parameters estimate mitochondrial respiration, reactive oxygen species (ROS) production, and deoxyribonucleotide (dNTP) balance in PBMCs. The population was drawn from the Metropolit cohort of men born in 1953. Vitality level was estimated from the Medical Outcomes Study Short Form 36 (SF-36) vitality scale. We found that vitality score had no association with any of the mitochondrial respiration parameters. However, vitality score was inversely associated with cellular ROS production and cellular deoxythymidine triphosphate (dTTP) levels and positively associated with deoxycytidine triphosphate (dCTP) levels. We conclude that self-reported persistent low vitality is not associated with specific aspects of mitochondrial oxidative phosphorylation capacity in PBMCs, but may have other underlying cellular dysfunctions that contribute to dNTP imbalance and altered ROS production.

Self-reported fatigue and physical function in late mid-life

OBJECTIVE

To determine the association between the 5 subscales of the Multidimensional Fatigue Inventory (MFI-20) and physical function in late mid-life.

DESIGN

Cross-sectional study.

SUBJECTS

A population-based sample of adults who participated in the Copenhagen Aging and Midlife Biobank population cohort (n = 4,964; age 49-63 years).

METHODS

Self-reported fatigue was measured using the MFI-20 comprising: general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue. Handgrip strength and chair rise tests were used as measures of physical function. Multiple logistic regression analyses were used to determine the associations between handgrip strength and the chair rise test with the MFI-20 subscales, adjusted for potential confounders.

RESULTS

After adjustments for potential confounders, handgrip strength was associated with physical fatigue (adjusted odds ratio (OR) 0.75 (95% confidence interval (CI) 0.66-0.86); p ≤ 0.001) and reduced motivation (adjusted OR 0.85 (95% CI 0.75-0.96); p ≤ 0.05), but not with the other subscales. After these adjustments, the chair rise test was associated with physical fatigue (adjusted OR 0.61 (0.53-0.69); p ≤ 0.001), general fatigue (adjusted OR 0.72 (0.62-0.84); p ≤ 0.001), reduced activity (adjusted OR 0.79 (0.70-0.90); p ≤ 0.001) and reduced motivation (adjusted OR 0.84 (0.74-0.95); p ≤ 0.01), but not with mental fatigue. Subgroup analyses for sex did not show statistically significant different associations between physical function and fatigue.

CONCLUSION

The present study supports the physiological basis of 4 subscales of the MFI-20. The association between fatigue and function was independent of gender.

Assessing fatigue in late-midlife: increased scrutiny of the Multiple Fatigue Inventory-20 for community-dwelling subjects

Previous methods examining the Multiple Fatigue Inventory-20 (MFI-20) fatigue questionnaire have been limited to classical test theory, for example, factor analytic approaches. We employed modern test theory to further strengthen the construct validity of the MFI-20 fatigue in a sample of healthy late-midlife subjects. Five subdimensions of perceived fatigue were examined in n = 7,233 subjects: general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue. Fatigue burden was compared across age groups (aged 48-52 vs. 57-63) and gender. Mokken item response theory was used to investigate dimensionality, monotonicity, and invariant item ordering (IIO). In both age groups, as well as by gender, the Motivation domain presented with weak scalability, suggesting that caution be exercised when interpreting sum scores. For all groupings, the strongest scaling properties were observed in the General Fatigue domain. However, the General Fatigue domain did not meet the property of IIO. Two domains (for all groupings) did meet the minimum criteria for the property of IIO: Physical Fatigue and Activity. Introducing model parameters for items served to enhance the interpretive power of the MFI-20, allowing for the identification of the most optimal scales. Poorly performing items were more easily identified, and person ability was assessed more accurately.

Single nucleotide polymorphisms in genes encoding toll-like receptors 7, 8 and 9 in Danish patients with systemic lupus erythematosus

Several studies indicate a role for toll-like receptors (TLRs) in the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate the risk of SLE and typical clinical and serological manifestations of SLE potentially conferred by selected single nucleotide polymorphisms (SNPs) of genes encoding TLR7, TLR8, and TLR9. Using a multiplexed bead-based assay, we analyzed eight SNPs in a cohort of 142 Danish SLE patients and a gender-matched control cohort comprising 443 individuals. Our results showed an association between the rs3853839 polymorphism of TLR7 and SLE (G vs. C, P = 0.008, OR 1.60, 95 % CI 1.12-2.27 in females; P = 0.02, OR 4.50, 95 % CI 1.18-16.7 in males) confirming recent findings in other populations. Additionally, an association between the rs3764879 polymorphism of TLR8 and SLE (G vs. C, P < 0.05, OR 1.36, 95 % CI 0.99-1.86 in females; P = 0.06, OR 4.00, 95 % CI 0.90-17.3 in males) was found. None of the other investigated SNPs were associated with SLE but several SNPs were associated with clinical and serological manifestations. In summary, a previously shown association between the rs3853839 SNP of TLR7 and SLE in Asian patients was also found in Danish patients. Together with the association of several other SNPs of TLR8 and TLR9 with various clinical and serological manifestations of SLE these findings corroborate the pathogenic significance of TLRs in SLE.

Association of physical workload and leisure time physical activity with incident mobility limitations: a follow-up study

OBJECTIVES

To examine individual as well as joint associations of physical workload and leisure time physical activity with incident mobility limitations in initially well-functioning middle-aged workers.

METHODS

This study is based on 6-year follow-up data of the Danish Longitudinal Study on Work, Unemployment and Health. Physical workload was reported at baseline and categorised as light, moderate or heavy. Baseline leisure time physical activity level was categorised as sedentary or active following the current recommendations on physical activity. Incidence of mobility limitations in climbing stairs and running among initially well-functioning workers (n=3202 and n=2821, respectively) was assessed during follow-up.

RESULTS

Higher workload increased whereas active leisure time decreased the risk of developing mobility limitations. The incidence of limitations increased progressively with higher workload regardless of level of leisure time physical activity, although the risks tended to be higher among those with sedentary leisure time compared with their active counterparts. All in all, the risk for onset of mobility limitations was highest among those with heavy workload combined with sedentary leisure time and lowest among those with light workload combined with active leisure time.

CONCLUSIONS

Although leisure time physical activity prevents development of mobility decline, high workload seems to accelerate the progression of mobility limitations among both those with active and sedentary leisure time. Therefore, efforts should be made to recommend people to engage in physical activity regardless of their physical workload.

Social class differences in physical functions in middle-aged men and women

OBJECTIVE

The objective of the present study is to analyze gender differences and social class gradients in physical functions; and to study whether the social class gradients in physical functions in midlife differed between men and women.

METHOD

This study used traditionally used physical performance tests and we added several tests of vigorous physical functioning (trunk muscle strength and power and sagittal flexibility). We measured reaction time, one-legged balance, sagittal flexibility, jump height, chair rise ability, trunk muscle- and handgrip strength in 5,412 participants aged 50 to 60 years (68.5% men).

RESULTS

We found gender differences and social class gradients for all physical performance tests. We did not find an interaction between social class and gender, indicating that the social gradient in physical functions did not differ between men and women.

DISCUSSION

Including measures of vigorous physical functioning may add to the existing knowledge on development of functional limitation and poorer functional health later in life.

Social gradient in allostatic load among Danish men and women in late midlife

OBJECTIVE

The objective of the present study is to describe the prevalence of allostatic load (AL) among Danish men and women in late midlife, and if there is a social gradient in AL.

METHOD

A total of 5,420 participants from the Copenhagen Aging and Midlife Biobank (CAMB) aged 48 to 63 years (68.5% men, 31.5% women) underwent a health examination including standardized measures of height, weight, body fat, and blood pressure in 2009-2011. AL (range 0-14) was established by summing the scores of the poorest quartile for each of 14 biological variables related to the metabolic and immune systems.

RESULTS

We found a social gradient in AL in late midlife among men and women living in Denmark.

DISCUSSION

AL may be a potential biomarker for early aging in countries with a strong social welfare system. It is important for intervention studies to be aware of this type of biological vulnerability already present in late midlife.

Addressing social inequality in aging by the Danish occupational social class measurement

OBJECTIVE

To present the Danish Occupational Social Class (DOSC) measurement as a measure of socioeconomic position (SEP) applicable in a late midlife population, and to analyze associations of this measure with three aging-related outcomes in midlife, adjusting for education.

METHOD

Systematic coding procedures of the DOSC measurement were applied to 7,084 participants from the Copenhagen Aging and Midlife Biobank (CAMB) survey. We examined the association of this measure of SEP with chronic conditions, self-rated health, and mobility in logistic regression analyses, adjusting for school education in the final analysis.

RESULTS

The measure of SEP showed a strong social gradient along the social classes in terms of prevalence of chronic conditions, poor self-rated health, and mobility limitations. Adjusting for school education attenuated the association only to a minor degree.

DISCUSSION

The DOSC measure was associated with aging-related outcomes in a midlife Danish population, and is, thus, well suited for future epidemiological research on social inequalities in health and aging.

Health, social and economic consequences of hypersomnia: a controlled national study from a national registry evaluating the societal effect on patients and their partners

Hypersomnia causes significant socioeconomic burden, but there is insufficient information about the time course and the effect on the partner. The aim of this study was to estimate the factual direct and productivity costs of hypersomnia in a controlled study including all national patients and their partners. Using records from the Danish National Patient Registry (1997-2009), we identified all patients with a diagnosis of hypersomnia and compared these patients and their partners with randomly chosen controls matched for age, gender, geographic area and marital status. Direct and productivity costs, including frequencies of primary and sector contacts and procedures, medication, labour supply and social transfer payments were extracted from the national databases. A total of 2,855 national patients was compared to 11,382 controls. About 70 % of patients and controls were married or cohabiting. Patients with hypersomnia had significantly higher rates of health-related contact, medication use and socioeconomic cost. Furthermore, they had slightly lower employment rates, and those in employment had a lower income level than control subjects. The annual mean excess health-related cost including social transfers was <euro>3,498 for patients with hypersomnia and <euro>3,851 for their partners. The social and health-related consequences could be identified up to 11 years before the first diagnosis among both the patients and their partners and became more pronounced as the disease advanced. The health effects were present in all age groups and in both genders. On the basis of this retrospective controlled study in the Danish population, symptoms and findings of hypersomnia are associated with major socioeconomic consequences for patients, their partners and society.

Psychosocial factors at work and the development of mobility limitations among adults in Denmark

AIM

Psychosocial factors in the working environment have been shown to be associated with mobility limitations, but this has not yet been confirmed in a Danish population. We aimed to examine how psychosocial factors at work are related to developing mobility limitations in Denmark.

METHODS

This study is based on data from 2952 middle-aged men and women without mobility limitations in 2000.

RESULTS

We found increased risk of incident mobility limitations during 6-year follow up among men who often perceived high work pace (OR 5.45, 95% CI 1.21-24.52) vs. never, who only sometimes or/never perceived the work to be meaningful (OR 6.54, 95% CI 1.55-27.55) vs. always, and who sometimes perceived high emotional demands at work (OR 7.85, 95% CI 1.78-34.65) vs. never. Among women, lower risk of incident mobility limitations was observed among those who in 2000 perceived high work pace sometimes (OR 0.46, 95% CI 0.24-0.87) or often (OR 0.43, 95% CI 0.22-0.85) vs. never in 2000. Also, women who always or often experienced high emotional demands had an increased risk.

CONCLUSIONS

The most important finding was that high work pace was strongly associated with increased risk of mobility limitations among men, but associated with lower risk of mobility limitations among women. This knowledge may be used to better target interventions among men and women in midlife from physical deterioration later in life.

The Relationship Between Cognitive Ability and Demographic Factors in Late Midlife

Objective: The aim of the article is to analyze associations between sex, age, education, and social class and cognitive ability in late midlife and to evaluate differences in cognitive ability among the three Copenhagen Aging and Midlife Biobank (CAMB) cohorts. Method: The sample comprised 5,417 CAMB participants from three cohorts with scores on the Intelligenz-Struktur-Test 2000 R (I-S-T 2000 R). Results: Independent associations of cognitive ability with age, sex, education, and occupational social class were observed. Particularly, strong associations with cognitive ability were obtained for school education, and consistent sex differences were observed with higher cognitive ability in men. Differences in cognitive ability among the three cohorts were small and primarily reflected demographic differences. Discussion: Late-midlife cognitive ability is associated with a number of demographic factors, and demographic differences may contribute to individual differences in health and early aging. In analyses of cognitive ability, the three CAMB cohorts can be combined provided the relevant demographic variables are included as covariates.

Content Validity and Reliability of the Copenhagen Social Relations Questionnaire

Objective: The aim of the present article is to describe the face and content validity as well as reliability of the Copenhagen Social Relations Questionnaire (CSRQ). Method: The face and content validity test was based on focus group discussions and individual interviews with 31 informants. Another 94 men and women participated in an 8-day test–retest analysis. Results: Informants generally expressed that the questions and response categories were relevant and easy to understand. Themes on structure of social relations, social support, and negative aspects of social relations emerged clearly from the interviews. Two additional themes not covered by CSRQ on dynamics and reciprocity of social relations were identified. Discussion: CSRQ holds satisfactory face and content validity as well as reliability, and is suitable for measuring structure and function of social relations including the negative aspects among middle-aged individuals.

Smoking and Drinking as Risk Indicators for Tooth Loss in Middle-Aged Danes

Objectives: To investigate tobacco and alcohol consumption as risk indicators for missing teeth in late middle-aged Danes. Method: In all, 1,517 Copenhagen Aging and Midlife Biobank (CAMB) participants received a clinical oral examination that included number of teeth. Information on smoking, drinking, and various covariates was obtained using self-administered, structured questionnaires. Descriptive statistics and logistic regression (dependent variable: 6+ vs. <6 missing teeth) were used to investigate smoking and drinking in relation to missing teeth. Results: Current smokers, persons who currently or previously smoked >15 tobacco units/day, and persons who had smoked for 27+ years had elevated mean scores of missing teeth and associated odds ratios (OR) compared with never smokers. Relative to nondrinkers, alcohol consumption was associated with reduced odds of missing 6+ teeth. Discussion: Our findings suggest that smoking is positively associated, while alcoholic beverage consumption is inversely related to tooth loss in middle-aged Danes.

Personality in Late Midlife

Objectives: To analyze associations in late midlife between sex, age, education and social class, and the Big Five personality traits; to analyze associations between personality traits and cognitive ability in late midlife; and to evaluate how these associations are influenced by demographic factors. Methods: The study sample comprised 5,397 late midlife participants from three cohorts who had completed the NEO Five-Factor Inventory (NEO-FFI) and a measure of cognitive ability. Results: Associations were demonstrated between the five NEO-FFI personality traits, and all included demographic factors. Cognitive ability and years of education correlated with several NEO-FFI personality traits in analyses adjusting for demographic variables. Cohort differences were observed for Extraversion and Openness. Discussion: Robust sex, educational, and social class differences in personality may contribute to late midlife social gradients in health and early aging. Demographic factors did not fully explain correlations between personality and cognitive ability or cohort differences in personality.

Subclinical cognitive decline in middle-age is associated with reduced task-induced deactivation of the brain's default mode network

Cognitive abilities decline with age, but with considerable individual variation. The neurobiological correlate of this variation is not well described. Functional brain imaging studies have demonstrated reduced task-induced deactivation (TID) of the brain's default mode network (DMN) in a wide range of neurodegenerative diseases involving cognitive symptoms, in conditions with increased risk of Alzheimer's disease, and even in advanced but healthy aging. Here, we investigated brain activation and deactivation during a visual-motor task in 185 clinically healthy males from a Danish birth cohort, whose cognitive function was assessed in youth and midlife. Using each individual as his own control, we defined a group with a large degree of cognitive decline, and a control group. When correcting for effects of total cerebral blood flow and hemoglobin level, we found reduced TID in the posterior region of the DMN in the cognitive decline group compared to the control group. Furthermore, increased visual activation response was found in the cognitive decline group, indicating that the TID reduction was not exclusively due to overall impaired vascular reactivity. These results suggest a neurobiological basis for subclinical cognitive decline in late midlife, which includes TID alterations similar to the pattern seen in patients with AD and mild cognitive impairment. Hence, TID reduction might be suggested as an early marker for subtle cognitive decline in aging.

Educational intervention and functional decline among older people: The modifying effects of social capital

Aim: To analyse if social capital modifies the effect of educational intervention of home visitors on mobility disability. Earlier studies have found that educational intervention of home visitors has a positive effect of older peoples′ functional decline, but how social capital might modify this effect is still unknown. Methods: We used the Danish Intervention Study on Preventive Home Visits – a prospective cohort study including 2863 75-year-olds and 1171 80-year-olds in 34 Danish municipalities – to analyse the modifying effect of different aspects of social capital on the effect of educational intervention of home visitors on functional decline. The three measures of social capital (bonding, bridging, and linking) were measured at contextual level. Data was analysed with multivariate linear regression model using generalised estimating equations to account for repeated measurements. Results: We found that 80-year-olds living in municipalities with high bonding ( B=0.089, p=0.0279) and high linking ( B=0.0929; p=0.0217) had significant better mobility disability in average at 3-year follow up if their municipality had received intervention. Conclusions: With the unique design of the Danish Intervention Study on Preventive Home Visits and with theory-based measures of social capital that distinguish between three aspects of social capital with focus on older people, this study contributes to the literature about the role of social capital for interventions on mobility disability.

Indoor mobility-related fatigue and muscle strength in nonagenarians: a prospective longitudinal study

BACKGROUND AND AIMS

Mobility-related fatigue is an important indicator of functional decline in old age, however, very little is known about fatigue in the oldest old population segment. The aim of this study was to examine the association between indoor mobility-related fatigue and muscle strength decline in nonagenarians.

METHODS

The study is based on a prospective longitudinal study of all Danes born in 1905 and assessed in 1998, 2000 and 2003, and includes 92- to 93-year-old persons who were independent of help in basic indoor mobility at baseline (n = 1,353). Fatigue was assessed at baseline and defined as a subjective feeling of fatigue when transferring or walking indoors. The outcome measure, maximum grip strength, was measured at each measurement point.

RESULTS

Grip strength declined throughout the study in participants with and without fatigue, but those reporting fatigue had significantly (P < .001) lower muscle strength during the entire study period. Longitudinal analyses indicated slightly slower decline in muscle strength among participants with fatigue compared to those without; however, observed selective dropout of participants with fatigue and poor performance at baseline needs to be considered when interpreting the results. Accordingly, participants without fatigue had significantly higher chances of being alive and having muscle strength above gender-specific median at first (RR 1.32, 95 % CI 1.07-1.58), second (RR 1.51, 1.06-1.96) and third (RR 1.39, 1.01-1.97) measurement points.

CONCLUSIONS

Indoor mobility-related fatigue in advanced later life should not merely be considered as an unpleasant symptom, but rather an indicator of physical impairment, and consequently declined physiological reserve.

Abstract W P126: Allostatic Load Predicts Stroke Mortality Risk in Older Danes: Findings From the 1914 Glostrup Aging Study

Allostatic load (AL) is a composite measure of cumulative biological damage derived from physiological markers across multiple systems. While previous reports have shown that AL predicts cardiovascular events at early old age, the prognostic value of AL on stroke mortality among the oldest old remains largely unexplored. The objective of this study was to evaluate the association between AL and stroke mortality risk in a birth cohort of older Danish adults from the 1914 Glostrup Aging Study. In total, 330 Danish participants completed a structured questionnaire at baseline (age 80) and were assessed for 10 physiological markers that spanned the cardiovascular (systolic and diastolic blood pressure, heart rate), metabolic (HDL, ratio of total cholesterol/HDL, BMI, triglycerides, serum albumin, blood glucose), and inflammatory (IL6, TNF-alpha) systems. Composite summary scores of AL ranging from 0-10 were computed for each participant using a count-based approach, with high and low cut-points of AL defined at the median. Using the Danish National Civil Death Registry, we ascertained deaths from cardiovascular disease and stroke for all participants and examined survival probability over a 15-year period with Cox regression. Overall, there were 106 cardiovascular disease-related deaths, of which 25 were due to stroke. Older adults with high AL had a 2-fold higher hazard risk of death from stroke than those with low AL (hazard ratio [HR]=1.96, 95% confidence interval [CI]: 0.89 - 4.35), after adjustment for conventional risk factors of stroke. When stratified by sex, men with high AL had about a 6-fold higher risk of death from stroke than those with low AL (adjusted HR= 5.67, 95% CI= 1.66 - 19.4). No association between AL and stroke mortality risk was observed in women (adjusted HR=0.78, 95% CI: 0.23 - 2.63) among whom there were only 6 stroke deaths. In a birth cohort of older Danish adults, AL showed promise as a prognostic tool for stroke mortality risk. Larger studies in more diverse populations are necessary to confirm our findings.

Longitudinal changes in leukocyte telomere length and mortality in humans

BACKGROUND

Leukocyte telomere length (LTL) ostensibly shortens with age and has been moderately associated with mortality. In humans, these findings have come almost solely from cross-sectional studies. Only recently has LTL shortening within individuals been analyzed in longitudinal studies. Such studies are relevant to establish LTL dynamics as biomarkers of mortality as well as to disentangle the causality of telomeres on aging.

METHODS

We present a large longitudinal study on LTL and human mortality, where the 10-year change of LTL is analyzed in 1,356 individuals aged 30-70 years.

RESULTS

We find age, smoking status, and alcohol consumption to be associated with LTL attrition and confirm a strong association with baseline LTL. The latter association might be an epiphenomenon of regression to the mean. We do not find an association of mortality with either absolute LTL or LTL attrition. Further, we show that DNA quality has an impact on TS ratios.

CONCLUSIONS

This study establishes that certain lifestyle factors influence LTL dynamics. However, it questions the applicability of LTL dynamics as a predictor of mortality. We suggest cautiousness when assessing actual LTL attrition due to the need for high-quality DNA and the phenomena of regression to the mean.

Intelligence in early adulthood and mortality from natural and unnatural causes in middle-aged Danish men

BACKGROUND

High intelligence early in life has consistently been associated with decreased mortality, but the mechanisms are still not fully understood. In this cohort study, we examined the association between intelligence in early adulthood and later mortality from natural and unnatural causes taking birth weight, parental socioeconomic position, participants' own education and body mass index into account.

METHODS

13 536 Danish men born in 1953 and 1959-1961 with data from birth certificates and intelligence test scores from conscription were followed until 2009. Information on vital status was obtained from the Civil Registration System. Mortality risks were analysed by the multiple Cox proportional hazards model.

RESULTS

The risk of mortality from natural as well as unnatural causes was more than twice as high among men in the lowest scoring intelligence tertile (HRnatural deaths=2.24; 1.90-2.65 and HRunnatural deaths=2.67; 2.03-3.53). Adjusting for all covariates attenuated the estimates, but the association remained (HRnatural deaths=1.82; 1.48-2.25 and HRunnatural deaths=2.30; 1.63-3.25).

CONCLUSIONS

In men, intelligence in early adulthood was inversely associated with midlife mortality from natural and unnatural causes. The associations remained after adjustments for a range of covariates.

Musculoskeletal pain and physical functioning in the oldest old

BACKGROUND

Little is known about the impact of pain on physical functioning among the oldest-old subjects. In this study, we first examined the associations between the number of painful sites and measures of physical functioning reflecting different stages of the disablement process (physical impairment, functional limitation and disability) among nonagenarians (more than ninety years old persons). Second, we described the effect of painful sites on disability during a 2-year follow-up period.

METHODS

This study is based on baseline (n = 1177) and 2-year follow-up (n = 709) data of the nationwide Danish 1905 cohort study. Musculoskeletal pain was assessed as reported pain in back, hips or knees when moving or resting. Physical performance measures included maximum grip strength and habitual walking speed. Disability in performing activities of daily living was defined as the need for assistive device or personal help in transferring, dressing, washing, using toilet and/or walking indoors.

RESULTS

At baseline, the number of painful sites was significantly associated with measured grip strength and walking speed as well as self-reported disability in a stepwise manner; the more sites with pain, the poorer the physical functioning. The follow-up analyses showed corresponding but slightly weaker stepwise associations between baseline pain and disability level at follow-up, and indicated that although on the whole, single or multi-site pain did not predict the onset of disability, multi-site pain increased the risk of developing severe disability.

CONCLUSIONS

The findings of this study suggest that musculoskeletal pain in nonagenarians is highly prevalent and is associated with poor physical performance and disability.

Improving a measure of mobility-related fatigue (the mobility-tiredness scale) by establishing item intensity

OBJECTIVES

To improve the construct validity of self-reported fatigue by establishing a formal hierarchy of scale items and to determine whether such a hierarchy could be maintained across time (aged 75-80), sex, and nationality.

DESIGN

Cohort study.

SETTING

Two Nordic urban locations: Jyväskylä, Finland, and Glostrup, Denmark.

PARTICIPANTS

Baseline (1989/90) consisted of a random sample of citizens of Finland or Denmark born in 1914 (n = 837). At 5-year follow-up, excluding those lost to follow-up and with baseline disability resulted in a sample of n = 690.

MEASUREMENTS

The Mobility-Tiredness (Mob-T) Scale is a six-item scale that requires subjects to self-report on whether they become tired performing mobility-related tasks. Employing item response theory, an attempt was made to enhance construct validity by confirming a hierarchy of mobility-related fatigue.

RESULTS

A formal hierarchy of fatigue tasks, maintained across time, was established using the revised Mob-T Scale. At age 75, the scalability statistics were a homogeneity coefficient (H) of 0.80, Ha T of 3.9% and an H(T) value of 0.66. The corresponding figures at age 80 were 0.75, 6.9% and 0.59. The property of invariant item ordering was maintained across subgroups based on sex and nationality.

CONCLUSION

Establishing a formal hierarchy at age 75 allowed which tasks were most debilitating to be identified more clearly and the individual's "distance" from these tasks to be gauged. Because it was possible to confirm that the item hierarchy was maintained across time (aged 75-80), researchers or clinicians can be more confident that performance over time is the result of real change and has less to do with measurement error.

Physical performance as long-term predictor of onset of activities of daily living (ADL) disability: a 9-year longitudinal study among community-dwelling older women

Disability in ADL of aging women is an important public health concern. It is thus of interest to identify modifiable factors underlying onset of ADL disability. We assessed whether three physical performance-based measurements could predict ADL disability 9 years later. The participants were 113 non-disabled community-dwelling women with a mean age of 79.5 years at baseline. The baseline examinations of physical performance were: functional reach, climbing steps and comfortable walking speed. ADL disability was defined as need of personal assistance in at least one of five basic ADL items. The participants were followed for 9 years. Logistic regression models were fitted for each of the physical performance measurements together with the covariates in relation to ADL disability. At follow-up 25.7% were disabled in ADL. All three performance measurements were significantly associated with the onset of ADL disability at 9 years of follow-up, however, only walking speed remained significantly related to onset of ADL disability, when all three performance measurements were included in the same model. In conclusion all the three performance measurements were related to onset of ADL disability, with walking speed having the strongest predictive value. Systematic screening based on walking speed measurements of non-disabled older women might help health professionals to identify those at risk of ADL disability and introduce preventive measures in time.

Occupational characteristics and cognitive aging in the Glostrup 1914 Cohort

OBJECTIVES

The effect of occupational characteristics on cognitive change over 20 years was examined.

METHOD

Occupational characteristics--intellectual challenge, physical hazards, and psychological demands--were assessed in the Glostrup 1914 Cohort when aged 60 years, and cognitive ability was assessed by 4 cognitive ability tests at ages 60, 70, and 80.

RESULTS

Individuals in more intellectually challenging occupations had higher cognitive ability (r = .27-.38, p < .01), whereas those in more physically hazardous occupations performed more poorly (r = -.12 and -.13 at ages 50 and 60, p < .05). In growth curve models, intellectual challenge continued to be associated with cognitive ability, controlling for sex, education, and social class. However, the association was reversed after accounting for cognitive ability at age 50; of 2 individuals with the same baseline level of cognitive ability, the one in the more intellectually challenging occupation had lower subsequent cognitive ability. The association of physical hazards with lower cognitive ability level did not remain after adjustment for the basic demographics, and none of the occupational characteristics were associated with cognitive change between age 60 and 80.

DISCUSSION

Notwithstanding the reversal of the effect of occupational intellectual challenge on cognitive ability level after accounting for pre-exiting cognitive differences, there was no evidence for long-term effects of occupational characteristics on cognitive change in old age.

Socio-economic position early in life, cognitive development and cognitive change from young adulthood to middle age

BACKGROUND

We examine the influence of social circumstances early in life on changes in cognitive function from young adulthood to middle age, and we explore the impact of birth characteristics, childhood activities, education and adult social class on the expected relationship.

METHODS

A cohort of 11 532 men born in Copenhagen, Denmark in 1953-7906, 10 246 and 2483 participants-had completed assessments of cognitive function at ages 12, 18 and 57 years, respectively. Linear regression was used to investigate the association of early-life characteristics with cognitive test scores at these ages and with score changes from early to mid-adulthood.

RESULTS

The cognitive scores at age 57 years had high correlations with scores at ages 12 (r = 0.67) and 18 years (r = 0.70), and these two scores also showed bivariate correlation (r = 0.69). Having a father from the working class at birth was associated with lower cognitive function at ages 12, 18 and 57 years. The latter relation was attenuated when educational status at age 18 years and adult social class were adjusted for, while birth characteristics and childhood activities had minor influence. Having an unskilled father at birth, low education, few intellectual and many social activities in childhood as well as low adult social class were associated with decline in cognitive function.

CONCLUSION

Adverse social circumstances early in life were associated with lower cognitive function at ages 12, 18 and 57 years, as well as with a decline between these ages. Educational status at age 18 years and adult social class seemed to account for most of the associations, whereas childhood activities were independent predictors that did not explain the social inequality.

Activity participation and cognitive aging from age 50 to 80 in the glostrup 1914 cohort

OBJECTIVES

To examine the cognitively protective effect of leisure and physical activities while accounting for prior cognitive ability, a rarely considered confounder of the previously reported associations between activity and cognitive aging.

DESIGN

Longitudinal cohort study.

SETTING

Glostrup, Denmark.

PARTICIPANTS

Community-dwelling sample of adults recruited into the Glostrup 1914 Cohort (baseline N = 802). All were born in 1914 and were assessed at ages 50, 60, 70, and 80. New participants were recruited during the study to counter attrition.

MEASUREMENTS

On each occasion, cognitive ability was assessed using four tests, which defined a general cognitive ability score. Self-reported participation in leisure and physical activities was also collected. In general, physical activity was summarized on a 3- or 4-point scale, and leisure activity as none versus some (ages 50 and 60) or according to participation in a list of common activities (age 70). The effect of activity-leisure and physical-on the level of cognitive ability and cognitive change over time from age 60 to 80 was examined in growth curve models.

RESULTS

Greater activity (leisure or physical) was consistently associated with a higher level of cognitive ability. Adjusting for baseline cognitive ability (age 50) attenuated these associations, suggesting that associations between activity and cognition reported in old age are largely a consequence of preserved differentiation. A small but significant association remained between greater physical activity at age 60 or 70 and less cognitive decline.

CONCLUSION

The association between more-frequent leisure activity and less cognitive decline mainly reflects the positive cross-sectional association between activity and cognition, although the link that remains between greater physical activity and a more-successful cognitive aging trajectory is of particular relevance to those who are developing interventions.

Do negative aspects of social relations influence fatigue? A cross-sectional study on a non-clinical sample of middle-aged Danish men

OBJECTIVE

Fatigue is a common complaint among young and old adults and may be associated with negative aspects of social relations. Hence, the purpose of this study was to explore the association between demands from and conflicts with different sources of social relations and fatigue.

METHODS

The study was based on sub-populations of the 6292 members of the Danish Metropolit Cohort. The cohort comprises men born in 1953 in the Copenhagen Metropolitan area who participated in a questionnaire survey in 2004. Data were analysed using χ(2)-tests and multivariable logistic regression.

RESULTS

The results showed that demands from and conflicts with children were independently associated with fatigue in a dose-response pattern. The adjusted odds ratio for fatigue was 1.48 (95% CI: 1.01-2.17) when the men experienced frequent demands from children and 1.89 (95% CI: 1.17-3.06) when they had frequent conflicts with their children. Crude analyses of demands from or conflicts with spouse, relatives or friends, respectively showed associations with fatigue compared to no demands or no conflicts. However, adjustment for depression and physical chronic disease cancelled out these associations.

CONCLUSION

We concluded that middle-aged Danish men, who had frequent negative social interactions with their children, more frequently experienced fatigue. However, negative social interactions with spouse, relatives or friends were not associated with fatigue.

Impact of Social Capital on 8-Year Mortality Among Older People in 34 Danish Municipalities

Objectives: To analyze the impact of social capital measures (bonding, bridging, and linking) on all-cause mortality at 8-year follow-up among older people aged 75 and 80 at baseline. Method: Prospective cohort study on preventive home visits including 2,863 seventy-five-year-olds and 1,171 eighty-year-olds in 34 Danish municipalities. The associations of the three aspects of social capital measures with mortality were tested in Cox regression models on time to death. Results: In the 80-year-old cohort significant associations were seen between mortality and both bridging (hazards ratio (HR) = 1.24, 95% CI [1.07, 1.45]) and linking (HR = 1.21, 95% CI [1.03, 1.43]), but the associations attenuated when controlling for relevant confounders. None of the social capital measures were associated with mortality among the 75-year-olds. Conclusion: The measures of social capital used in the present study include key aspects of social capital that are associated to mortality in older populations via physical activity and mobility disability.