Genetic and Environmental Influences on Longitudinal Trajectories of Functional Biological Age: Comparisons Across Gender.

We used an alternate age variable, functional biological age (fBioAge), which was based on performance on functional body measures. The aim was to examine development of fBioAge across the adult life span, and to also examine potential gender differences and genetic and environmental influences on change with age. We used longitudinal data (n = 740; chronological age (ChronAge) range 45-85 at baseline) from the Swedish Adoption/Twin Study of Aging. The rate of increase in fBioAge was twice as fast after ChronAge 75 than before. fBioAge was higher in women than in men. fBioAge was fairly equally influenced by genetic and environmental factors. Whereas the rate of ChronAge cannot vary across time, gender, or individual, our analyses demonstrate that fBioAge does capture these within and between individual differences in aging, providing advantages for fBioAge in the study of aging effects.

Different Context but Similar Cognitive Structures: Older Adults in Rural Bangladesh.

Most research in cognitive aging is based on literate participants from high-income and Western populations. The extent to which findings generalize to low-income and illiterate populations is unknown. The main aim was to examine the structure of between-person differences in cognitive functions among elderly from rural Bangladesh. We used data from the Poverty and Health in Aging (PHA) project in Bangladesh. The participants (n = 452) were in the age range 60-92 years. Structural equation modeling was used to estimate the fit of a five-factor model (episodic recall, episodic recognition, verbal fluency, semantic knowledge, processing speed) and to examine whether the model generalized across age, sex, and literacy. This study demonstrates that an established model of cognition is valid also among older persons from rural Bangladesh. The model demonstrated strong (or scalar) invariance for age, and partial strong invariance for sex and literacy. Semantic knowledge and processing speed showed weak (or metric) sex invariance, and semantic knowledge demonstrated also sensitivity to illiteracy. In general, women performed poorer on all abilities. The structure of individual cognitive differences established in Western populations also fits a population in rural Bangladesh well. This is an important prerequisite for comparisons of cognitive functioning (e.g., declarative memory) across cultures. It is also worth noting that absolute sex differences in cognitive performance among rural elderly in Bangladesh differ from those usually found in Western samples.

Factors associated with grip strength decline in older adults.

BACKGROUND: Few studies have examined associations of multi-faceted demographic, health and lifestyle factors with long-term change in grip strength performance across the adult lifespan. The aim of this study was to examine the associations of risk factors in specific parts of the adult lifespan (e.g. in early midlife, in late midlife and in old adulthood) separately for women and men. METHODS: Data came from the longitudinal Swedish Adoption/Twin Study of Aging (SATSA). Grip strength performance was followed in 849 participants who were 50-88 years of age at baseline. The follow-up period with seven waves of data of grip strength was 22 years, and the risk factors were measured up to 20 years before the assessment of grip strength. Latent growth modelling was used for the longitudinal analyses. RESULTS: A gender difference in the type of factors associated with grip strength performance and development across the adult lifespan was found. Significant factors for the age slopes for women were stress, smoking and dementia. For men, marital status, mean arterial pressure, physical activity at work and having a chronic disorder were of importance. These factors varied in their associations with grip strength across the adult lifespan. CONCLUSION: Factors measured earlier in adulthood were associated with grip strength decline in late midlife and old adulthood. Gender-specific patterns of risk factors suggest that it may be worthwhile to conduct research on grip and muscle strength (and biological vitality) separately for men and women.

Prevalence of depressive symptoms and suicidal thoughts among elderly persons in rural Bangladesh.

BACKGROUND: Depression, if broadly defined, is the commonest late-life mental disorder. We examined the distribution of depressive symptoms and suicidal thoughts, across age, sex, literacy, and marital status, among elderly individuals residing in rural Bangladesh and participating in a population-based study on health and aging. METHODS: Prevalence figures of depressive symptoms were assessed with SRQ20 (n = 625), and possible social network and economic associations were examined. Morbidity accounts of depressive symptoms and suicidal thoughts were examined for a subsample that also underwent complete medical examination (n = 471). RESULTS: We selected for analyses the items that corresponded to DSM-IV criteria and constructed a dichotomous variable. The prevalence was 45%, and most pronounced among the oldest women (70%). The overall prevalence of suicidal thoughts was 23%. Being a woman, illiterate or single were all risk factors for depressive symptoms and suicidal thoughts. These associations remained unaccounted for by the social network and economic variables. Co-residing with a child and having a high quality of contact were protective of both depressive symptoms and suicidal thoughts. The main findings were replicated in the subsample, where it was found that morbidities were also associated with the outcomes, independently of the four main predictors. CONCLUSIONS: Prevalence figures for depressive symptoms among elderly in rural Bangladesh are high. Demographic, social network, and morbidity factors are independently associated with both depressive symptoms and suicidal thoughts. This is the first study to report prevalence figures for depressive symptoms in this population.

Staffing agency: A bridge to working during retirement.

BACKGROUND: The ageing population has initiated a debate about a prolonged working life. There is an interest in finding the pre-retirement predictors of bridge employment and retirement decisions, but the understanding of the experiences of bridge employees is still limited. OBJECTIVES: The aim was to describe the characteristics of the pensioners working for a staffing agency, their motivational aspects, work patterns and types of services they provided. METHODS: This article analyses the results from a Swedish staffing agency's yearly co-worker questionnaire from December 2017. The response rate was 44% (N = 1741). The design is descriptive, with correlation analyses and construction of typical cases. RESULTS: Most study participants were aged 65-74 years. Sixty-five percent were men, 66% were cohabitating/married, dominating education level was secondary school or higher education (79%). Important incentives for working were the social context and to gain extra income. A majority of the respondents also stated that their work increased their overall well-being. Seventy-eight percent worked 25 hours per month or less, 37% wanted to work more, 3% wanted to work less. Private services dominated with 61%; most common were gardening (43%), trades (33%) and cleaning (31%). CONCLUSIONS: More men than women chose this form of work. While single women need to work out of economic necessity, men, to a larger extent, work for the social context and well-being. The highest work frequency in 2017 (14%) in the population was found for those who retired in 2015, i.e. two years after their retirement year. A majority indicated that the work they were doing was different from earlier in their working life.

Examination of the common cause account in a population-based longitudinal study with narrow age cohort design.

BACKGROUND: The common cause account suggests that there is a third factor causing aging effects in both sensory and cognitive functioning, hypothesized to be the integrity of the central nervous system [Lindenberger and Baltes; Psychol Aging 1994;9:339-355]. Importantly, the common cause account was developed based on cross-sectional data, which are especially biased by cohort effects. However, cohort effects can be controlled for in narrow age cohort (NAC) designs and by longitudinal examination. Findings from the few longitudinal studies that have studied the relation between age-related changes in sensory and cognitive functions are complex and give only partial support to the common cause account. OBJECTIVE: The present paper examines the common cause account within a longitudinal setting. METHOD: Our study is unique in the sense that it tests the common cause account within a longitudinal NAC design using data from the Betula project. The participants (n = 1,057) were in the age range of 45-90 years. RESULTS: The findings indicate that the relationship between sensory and memory functioning in both a longitudinal age-heterogeneous and a longitudinal NAC design are much weaker than that detected by an age-heterogeneous cross-sectional design. CONCLUSION: The demonstrated weak age-associated sensory-cognitive link raises questions regarding the explanatory value of the common cause account and related theoretical accounts for accounting for age-related cognitive changes.

Associations Between Functional Biological Age and Cognition Among Older Adults in Rural Bangladesh: Comparisons With Chronological Age.

OBJECTIVES: We constructed a functional biological age (fBioAge) indicator by using four functional variables: grip strength, forced expiratory lung volume, visual acuity, and hearing. Our aim was to compare how chronological age (ChronAge) and fBioAge are related to cognitive abilities in older adults. METHOD: We used data from the Poverty and Health in Aging project, Bangladesh. Participants ( N = 400) were 60+ years of age and diagnosed as nondemented. Examined cognitive abilities were four episodic memory measures (including recall and recognition), two verbal fluency indicators, two semantic knowledge, and two processing speed tasks. RESULTS: fBioAge accounted for cognitive variance beyond that explained by ChronAge also after controlling for medical diagnoses and blood markers. DISCUSSION: Compared with ChronAge, fBioAge was a stronger predictor of cognition during a broad part of the old adult span. fBioAge seems, in that respect, to have the potential to become a useful age indicator in future aging studies.

Functional Aging Index Complements Frailty in Prediction of Entry Into Care and Mortality.

BACKGROUND: The aim of this study was to develop a functional aging index (FAI) that taps four body systems: sensory (vision and hearing), pulmonary, strength (grip strength), and movement (gait speed) and to test the predictive value of FAI for entry into care and mortality. METHOD: Growth curve models and Cox regression models were applied to data from 1,695 individuals from three Swedish longitudinal studies of aging. Participants were aged 45-93 at intake and data from up to eight follow-up waves were available. RESULTS: The rate of change in FAI was twice as fast after age 75 as before, women demonstrated higher mean FAI, but no sex differences in rates of change with chronological age were identified. FAI predicted entry into care and mortality, even when chronological age and a frailty index were included in the models. Hazard ratios indicated that FAI was a more important predictor of entry into care for men than women, whereas it was a stronger predictor of mortality for men than women. CONCLUSIONS: Measures of biological aging and functional aging differ in their predictive value for entry into care and mortality for men and women, suggesting that both are necessary for a complete picture of the aging process across genders.

Everyday Health among Older People: A Comparison between Two Countries with Variant Life Conditions.

This study described health factors of importance for everyday health, such as pain, tiredness, and sleeping problems, in a cross-national context. Data for persons 60+ years were obtained from the Poverty and Health in Aging study, Bangladesh, and the Swedish National Study on Aging and Care-Blekinge. The strongest associations with everyday health in Sweden were found for pain and tiredness, while in Bangladesh they were financial status, tiredness, and sleeping problems. As similarities were found regarding the associations of tiredness on everyday health, tiredness may be a universal predictor of everyday health in older adults irrespective of country context.

Grip Strength and Cognitive Abilities: Associations in Old Age.

OBJECTIVES: Both physical functioning and cognitive abilities are important for well-being, not least in old age. Grip strength is often considered an indicator of general vitality and, as such, may predict cognitive functioning. Few longitudinal studies have examined the relationship between grip strength and cognition, especially where specific cognitive abilities have been targeted. METHOD: Participants (n = 708, age range: 40-86 years at baseline) came from the population-based longitudinal Swedish Adoption/Twin Study of Aging. We used a longitudinal follow-up of 6 waves during 20 years. For the analyses, we used latent growth modeling, where latent growth trajectories were fitted to the cognitive traits (verbal ability, spatial ability, processing speed, and memory) or to the grip strength values and each, respectively, treated as time-varying covariates of the other trait. RESULTS: Results supported a longitudinal influence of grip strength on changes in cognitive function. Grip strength performance was associated with change in the 4 cognitive abilities after age 65 years. DISCUSSION: A rather stable connection was found between grip strength and cognitive abilities starting around 65 years of age. The starting period suggests that the association may be due to lifestyle changes, such as retirement, or to acceleration of the aging processes.

A cross-cultural perspective on aging and memory: Comparisons between Bangladesh and Sweden.

Most studies on cognitive aging have been conducted in high-income countries (mainly on Western populations). The main aim of this study was to compare the relative importance of predictors of episodic and semantic memory performance in older people (≥60 years) from Bangladesh (n = 400) and Sweden (n = 1,098). Hierarchical regression models were used in order to study the importance of some commonly used predictors in the two countries. A main finding was that variations in age did not have much impact on episodic and semantic memory performance in Bangladesh. Instead, sex was a strong predictor for semantic memory performance. In Sweden this pattern was reversed. In the Western world, chronological age is believed to be strongly associated with memory performance in cross-sectional studies, particularly in people greater than 60 years of age. This study indicates that the difference between the two countries (in relative importance of the predictors included in this study) is mainly due to the fact that years of education is connected to age in the Western world but to sex in Bangladesh. It remains to be examined whether earlier selective survival is also responsible for the relative absence of cognitive age differences in Bangladesh.

Hearing loss is negatively related to episodic and semantic long-term memory but not to short-term memory.

PURPOSE: To test the relationship between degree of hearing loss and different memory systems in hearing aid users. METHOD: Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without dementia, drawn from the Swedish prospective cohort aging study known as Betula (L.-G. Nilsson et al., 1997). RESULTS: Hearing loss was selectively and negatively related to episodic and semantic long-term memory (LTM) but not short-term memory (STM) performance. This held true for both ears, even when age was accounted for. Visual acuity alone, or in combination with auditory acuity, did not contribute to any acceptable SEM solution. CONCLUSIONS: The overall relationships between hearing loss and memory systems were predicted by the ease of language understanding model (J. Rönnberg, 2003), but the exact mechanisms of episodic memory decline in hearing aid users (i.e., mismatch/disuse, attentional resources, or information degradation) remain open for further experiments. The hearing aid industry should strive to design signal processing algorithms that are cognition friendly.

Challenging the notion of an early-onset of cognitive decline.

Salthouse claims that cognitive aging starts around 20 years of age. The basis for this claim is cross-sectional data. He dismisses longitudinal data, which typically show the cognitive decline to start much later, around 60 years of age. He states that longitudinal data cannot be trusted because they are flawed. There is a confounding between the effects of maturation and retest effects. We challenge Salthouse's strong claim on four accounts.

Examination of the processing speed account in a population-based longitudinal study with narrow age cohort design.

The processing speed account suggests that general slowing of mental processing speed results in an overall decline, especially age-related decline, in other cognitive domains. Support for the speed account comes mainly from cross-sectional studies with participants that vary in age (age-heterogeneous samples). This study investigated how well variations in processing speed predict change of episodic recall in a longitudinal framework and examined with the Narrow Age Cohort (NAC) design. Data were obtained from Betula, a population-based longitudinal study. Both 5-year (n= 490; Time 3 - Time 4) and 10-year follow-up results (n= 608; Time 1 - Time 3) were used. In both samples, which were subjected to prospective dementia screening, we found considerably weaker associations in longitudinal data compared to cross-sectional, and also weaker associations in age-homogeneous than in age-heterogeneous samples. The results provide little support for the speed account.