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.

Sex-specific associations between self-reported sleep duration, depression, anxiety, fatigue and daytime sleepiness in an older community-dwelling population.

PURPOSE: The purpose of this study was to explore whether associations between self-reported sleep duration, depressive symptoms, anxiety, fatigue and daytime sleepiness differed in older community-dwelling men and women. DESIGN: Cross-sectional. METHODS: A community-dwelling sample of 675 older men and women (mean age 77.7 years, SD 3.8 years) was used. All participants underwent a clinical examination by a cardiologist. Validated questionnaires were used to investigate sleep duration, depressive symptoms, anxiety, fatigue and daytime sleepiness. Subjects were divided into short sleepers (≤6 hours), n = 231; normal sleepers (7-8 hours), n = 338; and long sleepers (≥9 hours), n = 61. ancovas were used to explore sex-specific effects. RESULTS: Depressive symptoms were associated with short sleep in men, but not in women. Fatigue was associated with both short and long sleep duration in men. No sex-specific associations of sleep duration with daytime sleepiness or anxiety were found. CONCLUSION: Nurses investigating sleep duration and its correlates, or effects, in clinical practice need to take sex into account, as some associations may be sex specific. Depressive symptoms and fatigue can be used as indicators to identify older men with sleep complaints.

Sex-Specific Associations Between Self-reported Sleep Duration, Cardiovascular Disease, Hypertension, and Mortality in an Elderly Population.

BACKGROUND: Both short and long sleep durations have been associated to increased mortality. Knowledge about sex-specific differences among elderly regarding associations between sleep duration, cardiovascular health, and mortality is sparse. OBJECTIVE: The aims of this study are to examine the association between self-reported sleep duration and mortality and to investigate whether this association is sex specific and/or moderated by cardiovascular morbidity, and also to explore potential mediators of sleep duration effects on mortality. METHODS: A population-based, observational, cross-sectional design with 6-year follow-up with mortality as primary outcome was conducted. Self-rated sleep duration, clinical examinations, echocardiography, and blood samples (N-terminal fragment of proBNP) were collected. A total of 675 persons (50% women; mean age, 78 years) were divided into short sleepers (≤6 hours; n = 231), normal sleepers (7-8 hours; n = 338), and long sleepers (≥9 hours; n = 61). Data were subjected to principal component analyses. Cardiovascular disease (CVD) and hypertension factors were extracted and used as moderators and as mediators in the regression analyses. RESULTS: During follow-up, 55 short sleepers (24%), 68 normal sleepers (20%), and 21 long sleepers (34%) died. Mediator analyses showed that long sleep was associated with mortality in men (hazard ratio [HR], 1.8; P = .049), independently of CVD and hypertension. In men with short sleep, CVD acted as a moderator of the association with mortality (HR, 4.1; P = .025). However, when using N-terminal fragment of proBNP, this effect became nonsignificant (HR, 3.1; P = .06). In woman, a trend to moderation involving the hypertension factor and short sleep was found (HR, 4.6; P = .09). CONCLUSION: Short and long sleep duration may be seen as risk markers, particularly among older men with cardiovascular morbidity.

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.

Cognitive function did not improve after initiation of natalizumab treatment in relapsing-remitting multiple sclerosis. A prospective one-year dual control group study.

BACKGROUND: Cognitive impairment in multiple sclerosis (MS) is common and has severe implications. Natalizumab (NZ) has documented effects on relapse rate and radiological disease activity in relapsing-remitting MS (RRMS) but studies regarding its specific effects on cognitive functioning are few. Previous studies have reported improvement, however, often lacking relevant control groups. The objective of the present study was to evaluate the cognitive effects of NZ treatment, compared to patients on stable first-line treatment and healthy control subjects. METHODS: MS patients starting NZ (MS-NZ), MS controls with stable interferon beta therapy (MS-C) and healthy control subjects (HC) were evaluated twice with one year interval, using a cognitive test battery covering six cognitive domains. The effects of NZ on levels of self-reported depression, fatigue, daytime sleepiness and perceived health were also examined. RESULTS: MS patients (MS-NZ and MS-C) had significantly lower baseline cognitive performance compared to HC (global score, p=0.002), but there were no significant differences between MS-NZ and MS-C. At follow-up, both MS-NZ and MS-C had improved significantly in four and five cognitive domains, respectively, and in global score (p=0.013 and p<0.001, respectively). HC improved significantly in three cognitive domains but not in global score. A regression analysis including baseline cognitive z-score and z-score change showed that participants with lower baseline scores had a significantly greater improvement, compared to those with better initial performance (p=0.021). There were no significant changes in depression, fatigue, daytime sleepiness or perceived health in MS-NZ or MS-C. CONCLUSIONS: Initiation of NZ therapy did not result in true cognitive improvement over one year. Presumably, the increased test performance in both MS groups was artificial and due to retest effects that were stronger in patients with lower baseline performance. Adequate control groups are essential when evaluating cognitive functioning in intervention trials among RRMS patients.

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.

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.

Event related potential and response time give evidence for a physiological reserve in cognitive functioning in relapsing-remitting multiple sclerosis.

Cognitive dysfunction is common in multiple sclerosis (MS). Different factors may moderate the degree of cognitive deficit. The aim of the present study was to distinguish different mechanisms for cognitive reserve in relapsing-remitting MS (RRMS). The effects of clinical variables (physical disability, depression), premorbid intelligence (years of education, vocabulary knowledge), visual event-related potential measures (P300) and response time (RT) were studied in RRMS patients (n=71) and healthy subjects (n=89). Patients with high P300 amplitude and short RT had better cognitive performance. This effect was significantly weaker in controls. High P300 and short RT may be physiological markers of a cognitive reserve in RRMS. In contrast, the association between cognitive scores and premorbid intelligence was similar in patients and in control subjects. The effects of physiological reserve and clinical variables were studied in a hierarchical linear regression model of cognitive performance in RRMS. P300 amplitude and RT explained a considerable amount of variance in global cognitive performance (34%, p<0.001). The effects of P300 and RT were not moderated by premorbid intelligence. Physical disability and depression added significantly to explained variance, and the final model accounted for 44% (p<0.001) of the variation. We conclude that physiological reserve is the strongest moderator of cognitive impairment in RRMS.

P300 amplitude and response speed relate to preserved cognitive function in relapsing-remitting multiple sclerosis.

OBJECTIVE: To explore if cognitive impairment in relapsing-remitting multiple sclerosis (RRMS) is associated with abnormal neural function and if there is evidence of neural compensatory mechanisms. METHODS: Seventy-two RRMS patients and 89 healthy control subjects were included in a cross-sectional study. Event-related brain potential (P300) and response time (RT) were recorded with visual and auditory choice reaction tasks. Cognitive function was evaluated with an 18 item test battery. RESULTS: Patients had a decrease in cognitive function (p<0.001 for global score) and increased visual P300 amplitude frontally. P300 amplitude was normal in other brain areas and RT was normal. P300 latency was normal except for an increase in auditory latency occipitally. Cognitive performance correlated positively with parietal P300 amplitude in patients but not in controls. Cognition had stronger correlation (negative) with RT in patients than in controls. CONCLUSIONS: Patients with low P300 amplitude and long RT were more often cognitively impaired. This indicates that general factors such as signal amplitude and speed are limiting for cognitive function in RRMS patients. The increase in frontal P300 amplitude may be a compensatory effect. SIGNIFICANCE: Our findings suggest that high amplitude and fast speed may be protective against cognitive impairment.

Non-Verbal and Verbal Fluency in Prodromal Huntington's Disease.

BACKGROUND: This study examines non-verbal (design) and verbal (phonemic and semantic) fluency in prodromal Huntington's disease (HD). An accumulating body of research indicates subtle deficits in cognitive functioning among prodromal mutation carriers for HD. METHODS: Performance was compared between 32 mutation carriers and 38 non-carriers in order to examine the magnitude of impairment across fluency tasks. The predicted years to onset (PYTO) in mutation carriers was calculated by a regression equation and used to divide the group according to whether onset was predicted as less than 12.75 years (HD+CLOSE; n = 16) or greater than 12.75 years (HD+DISTANT; n = 16). RESULTS: The results indicate that both non-verbal and verbal fluency is sensitive to subtle impairment in prodromal HD. HD+CLOSE group produced fewer items in all assessed fluency tasks compared to non-carriers. HD+DISTANT produced fewer drawings than non-carriers in the non-verbal task. PYTO correlated significantly with all measures of non-verbal and verbal fluency. CONCLUSION: The pattern of results indicates that subtle cognitive deficits exist in prodromal HD, and that less structured tasks with high executive demands are the most sensitive in detecting divergence from the normal range of functioning. These selective impairments can be attributed to the early involvement of frontostriatal circuitry and frontal lobes.

Prevalence of dementia and factors associated with dementia in rural Bangladesh: data from a cross-sectional, population-based study.

BACKGROUND: There are currently no published reports of dementia prevalence or factors associated with dementia occurrence in Bangladesh. The aims are to report the prevalence of definite and questionable dementia in rural Bangladesh, and examine factors potentially associated with dementia occurrence, including sociodemographic, clinical, social, and nutritional factors. METHODS: We used data from a population-based, cross-sectional study from Matlab, in rural Bangladesh, on 471 persons aged 60+ years. Participants underwent a clinical examination including diagnosis of somatic disorders, and a structured interview including questions about sociodemographic and social factors. Nutritional status was measured with the Mini Nutritional Assessment, and blood tests were conducted to assess a range of nutritional and clinical aspects. Age- and sex-specific dementia prevalence was calculated. Crude and adjusted logistic regression was used to examine associations between dementia and clinical, social, and nutritional factors. Dementia was diagnosed using a two-step procedure by physicians according to DSM-IV criteria. RESULTS: The prevalence of questionable dementia was 11.5% and definite dementia was 3.6%. Dementia prevalence increased with increasing years of age (adjusted OR: 1.04; 95% CI = 1.002-1.1) and decreased with more years of education (adjusted OR: 0.8; 95% CI = 0.6-0.99). Being malnourished increased the odds of dementia almost six-fold (adjusted OR: 5.9; 95% CI = 1.3-26.3), while frequent participation in social activities was associated with a decreased odds (adjusted OR: 0.5; 95% CI = 0.2-0.9). CONCLUSIONS: The prevalence of dementia in rural Bangladesh is similar to other countries in the South Asia region, but lower than reports from other world regions. Malnutrition is strongly associated with dementia occurrence, and is a relevant area for future research within low-income countries.

Cognitive impairment has a strong relation to nonsomatic symptoms of depression in relapsing-remitting multiple sclerosis.

It is unclear how cognitive impairment in multiple sclerosis (MS) is influenced by physical disability, fatigue, and depression. Our aim was to identify the strongest clinical predictors for cognitive impairment in relapsing-remitting MS (RRMS) patients. The clinical risk factors included in the analysis were physical disability (EDSS), fatigue (FSS), the somatic and nonsomatic components of depression (BDI), disease progression rate [Multiple Sclerosis Severity Score (MSSS)], and psychotropic medication. Cognitive impairment had a prevalence of 30.5% in patients affecting preferentially attention, executive functions, processing speed and visual perception/organization. MSSS was not associated with cognitive impairment, depression, or fatigue. In regression models, cognitive performance was best predicted by the nonsomatic symptoms of depression alone or in combination with physical disability. Exclusion of patients with any psychotropic medication did not influence the results. Our results underscore the importance of evaluating depressive symptoms when suspecting cognitive impairment in patients with RRMS.

A principal component model of medical health: implications for cognitive deficits and decline among adults in a population-based sample.

Longitudinal blood- and cognitive data from 879 adults were analyzed to extract a multidimensional health structure for prediction of cognitive change. Six health components were identified and replicated at two waves. Following, cognitive outcomes were regressed on the health components. Large proportions of cognitive age related variations were accounted for by baseline health in both cross-sectional and prospective analyses. Less variation was accounted for when health change and cognitive change were contrasted. Cardiovascular health was particularly important for prediction of cognitive change. Our study underlines causal relations between health and cognitive functions, and suggests that some effects are long term.

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.

Prevalence and patterns of multimorbidity among elderly people in rural Bangladesh: a cross-sectional study.

Data on multimorbidity among the elderly people in Bangladesh are lacking. This paper reports the prevalence and distribution patterns of multimorbidity among the elderly people in rural Bangladesh. This cross-sectional study was conducted among persons aged > or = 60 years in Matlab, Bangladesh. Information on their demographics and literacy was collected through interview in the home. Information about their assets was obtained from a surveillance database. Physicians conducted clinical examinations at a local health centre. Two physicians diagnosed medical conditions, and two senior geriatricians then evaluated the same separately. Multimorbidity was defined as suffering from two or more of nine chronic medical conditions, such as arthritis, stroke, obesity, signs of thyroid hypofunction, obstructive pulmonary symptoms, symptoms of heart failure, impaired vision, hearing impairment, and high blood pressure. The overall prevalence of multimorbidity among the study population was 53.8%, and it was significantly higher among women, illiterates, persons who were single, and persons in the non-poorest quintile. In multivariable logistic regression analyses, female sex and belonging to the non-poorest quintile were independently associated with an increased odds ratio of multimorbidity. The results suggest that the prevalence of multimorbidity is high among the elderly people in rural Bangladesh. Women and the non-poorest group of the elderly people are more likely than men and the poorest people to be affected by multimorbidity. The study sheds new light on the need of primary care for the elderly people with multimorbidity in rural Bangladesh.

The metabolic syndrome: prevalence, associated factors, and impact on survival among older persons in rural Bangladesh.

OBJECTIVES: To describe the prevalence of the metabolic syndrome (MetS) among older persons in rural Bangladesh, to investigate whether the prevalence varies by age, sex, literacy, marital status, nutritional status and socio-economic status, and to assess the impact of MetS on survival. METHODS: The study consisted of 456 persons who were aged ≥60 years living in a rural area of Bangladesh during July 2003-March 2004. Data were collected through interview, clinical examination, and laboratory tests, and their survival status until 30(th) June 2009 was ascertained through the Matlab surveillance system. We defined MetS following the NCEP ATP III criteria, with minor modifications, i.e., presence of any three of the following: hypertension (BP ≥130/85 mm Hg); random blood glucose (RBG) level ≥7.0 mmol/L; hyper-triglyceridemia (≥2.28 mmol/L); low level of HDL-cholesterol (<1.04 mmol/L for men and <1.29 mmol/L for women); and BMI ≥25.0 kg/m(2). Data were analysed with logistic regressions for the influential factors of MetS, and with Cox models for the association of MetS with the survival status. FINDINGS: The overall prevalence of MetS was 19.5%, 20.8% in women, and 18.0% in men. Asset-index and nutritional status were independently associated with MetS. During 4.93 years of follow-up, 18.2% died. In the presence of high RBG, MetS has a significant negative effect on survival (69.4% vs 95.2%, log rank p = 0.02). CONCLUSION: This study highlights the importance of the metabolic syndrome in rural Bangladesh. Our findings suggest that there is a need for screening programmes involving the metabolic syndrome to prevent diabetes and cardiovascular diseases.

Post polio syndrome: fatigued patients a specific subgroup?

OBJECTIVES: To examine the characteristics of fatigued and non-fatigued post-polio patients and to define potential subgroups across the fatigue continuum. DESIGN: Multi-centre study. SUBJECTS: A total of 143 post-polio patients were subdivided on the basis of percentile distribution into a fatigue group, a intermediate group, and a non-fatigue group, using the Multi Fatigue Inventory 20 general fatigue ratings. METHODS: Data on background, quality of life, fatigue and pain were collected. Descriptive statistics and correlations in each group and analysis of variance and χ2 for group comparisons were performed. Non-linear regressions were employed to evaluate differences in the strength of associations between physical and mental fatigue, on the one hand, and vitality on the other. RESULTS: The fatigued group was younger, had shorter polio duration, more pain, higher body mass index, lower quality of life and was more physically and mentally fatigued. A higher proportion of this group had contracted polio after 1956 and was under 65 years of age. Mental fatigue had a relatively higher explanatory value than physical fatigue for differences in vitality in the fatigued group, whereas reversed patterns were seen in the other groups. CONCLUSION: Fatigued post-polio patients can be considered as a subgroup.

Effects of intensified metabolic control on CNS function in type 2 diabetes.

The mild cognitive decline associated with type 2 diabetes (T2DM) has been suggested to be reversible with improved glycemic control. In order to characterise this cognitive decline and study the effects of improved glycemic control we have studied patients with T2DM (N=28) and healthy control subjects (N=21). One group of patients with diabetes (N=15) were given a 2-month treatment of intensified glycemic control, whereas the other group (N=13) maintained their regular treatment. Cognitive function in four different domains, auditory event-related potentials (ERPs) and resting EEG power spectrum were studied in the two groups of patients and in healthy control subjects before and after the 2-month trial period. There were significant differences at baseline (p<0.02) between patients with T2DM and controls. Patients had lower scores in two cognitive domains: verbal fluency (p<0.01) and visuospatial ability (p<0.03). T2DM also affected ERP with a decrease in N100 amplitude (p<0.04) and an increase in P300 latency (p<0.03). Furthermore, resting EEG activity in the beta band (13-30Hz) was reduced (p<0.04). The change between 1st and 2nd investigation was significantly different in the three groups of patients/subjects (p<0.03). Patients receiving intensified treatment for glycemic control had an improvement of cognitive ability in visuospatial ability (p<0.02) and semantic memory performance (p<0.04) together with increased resting EEG activity in the alpha band (8-13Hz, p<0.02) and connectivity in the theta (4-8Hz, p<0.03) and alpha bands (p<0.03) over central and lateral regions. Furthermore, there was an increase in the connectivity in the beta band (p<0.04) over the central regions of the scalp. In conclusion, subjects with T2DM had a similar type of cognitive function impairment and EEG/ERP abnormality as previously demonstrated for subjects with type 1 diabetes (T1DM). Intensified therapy showed cognitive improvement not shown for regular treatment, suggesting that the negative effect of T2DM on cognition is reversible by means of improved glycemic control. Furthermore, there was an improvement in electro-physiological measures, suggesting increased availability of compensatory mechanisms in subjects with intensified treatment.