Sex-specific health deterioration and mortality: the morbidity-mortality paradox over age and time

[The gender paradox in health-impaired lifetime-end of a myth?]

BACKGROUND

Women live longer than men, but they spend more life years with health-impairment. This article examines the extent to which this gender paradox can be explained by two factors: the "mortality effect," which results from the higher life expectancy of women, and "differential item functioning" (DIF), which refers to gender differences in reporting behavior.

METHODS

Impaired life expectancy at age 50 is calculated for the health indicators general health, limitations, and chronic morbidity using the Sullivan method. Data on health prevalence are obtained from the 2012 survey "Gesundheit in Deutschland aktuell" (GEDA), data on mortality is taken from the Human Mortality Database. The gender difference in impaired life expectancy is decomposed into the mortality effect and the health effect. The latter is finally adjusted for DIF effects on the basis of vignettes from the 2004 SHARE survey.

RESULTS

The gender paradox can be resolved not only partially but completely for all three health indicators considered by the mortality effect and DIF. After taking these two factors into account, the gender difference in impaired life expectancy reverses from higher values for women to higher values for men.

DISCUSSION

The causes of the gender paradox are highly complex and the differences between women and men in total and impaired life expectancy are not necessarily going into contradictory directions. The extent of women's higher impaired life expectancy depends decisively on the underlying health indicator and is largely explained by the mortality effect.

Comparison of Frailty and Chronological Age as Determinants of the Murine Gut Microbiota in an Alzheimer's Disease Mouse Model

The ageing of an organism is associated with certain features of functional decline that can be assessed at the cellular level (e.g., reduced telomere length, loss of proteostasis, etc.), but also at the organismic level. Frailty is an independent syndrome that involves increased multidimensional age-related deficits, heightens vulnerability to stressors, and involves physical deficits in mainly the locomotor/muscular capacity, but also in physical appearance and cognition. For sporadic Alzheimer's disease, age per se is one of the most relevant risk factors, but frailty has also been associated with this disease. Therefore, we aimed to answer the two following questions within a cross-sectional study: (1) do Alzheimer's model mice show increased frailty, and (2) what changes of the microbiota occur concerning chronological age or frailty? Indeed, aged 5xFAD mice showed increased frailty compared to wild type littermates. In addition, 5xFAD mice had significantly lower quantities of Bacteroides spp. when only considering frailty, and lower levels of Bacteroidetes in terms of both frailty and chronological age compared to their wild type littermates. Thus, the quality of ageing-as assessed by frailty measures-should be taken into account to unravel potential changes in the gut microbial community in Alzheimer's disease.

Could an optimally fitted categorization of difference between multi-disease score and multi-symptom score be a practical indicator aiding in improving the cost-effectiveness of healthcare delivery for older adults in developing countries?

BACKGROUND

Physio-psycho-socioeconomical health comprehensively declines during aging, the complexity of which is challenging to measure. Among the complexity, multiple chronic disorders continuously cumulated during aging, further aggravating the challenge.

METHODS

A population-based survey on Comprehensive Ageing Health Assessment was conducted in older adults (age >  = 60) enrolled from hospital settings and community settings in 13 working centers in six subnational regions in China. Cross-sectional datasets of 8,093 older participants with approximately complete assessment results were collected for the present analysis. Individual's multi-disease or multi-symptom was respectively scored by summing coexistent multiple diseases or multiple symptoms by respective weighting efficient for Self-Rated Health (SRH). Individual's age-dependent health decline was further summed of four SRH-weighted scores for daily function (activity of daily life, ADL), physical mobility (an average of three metrics), cognitive function (mini mental state examination, MMSE) and mental being (geriatric depression scale, GDS) plus multi-disease score (MDS) and multi-symptom score (MSS).Multi-disease patten among 18 diseases or multi-symptom pattern among 15 symptoms was latent-clustered in the older adults, the optimal outcome of which was categorized into high, moderate or low aging-associated clusters, respectively. Percentage distribution was compared between overall health decline score and multi-disease pattern cluster or multi-symptom patten cluster. A new variable of difference between MDS and MSS (hereinafter terming DMM) that displayed linear variation with socioeconomic factors was further fitted using multilevel regression analyses by substantial adjustments on individual confounders (level-1) and subnational region variation (level-2).

RESULTS

Consistent gradient distribution was shown between health decline and multimorbidity pattern cluster in the older adults. DMM was found linearly varied with personal education attainment and regional socioeconomic status. Using optimally fitted stratification of DMM (DMM interval = 0.02), an independent U-shaped interrelated tendency was shown between health decline, multi-disease and multi-symptom, which could be well explained by regional disparities in socioeconomic status.

CONCLUSION

Newly developed metrics for age-dependent health decline and aging-associated multimorbidity patten were preliminarily validated from within. The new variable of optimally fitted categorization of DMM might function as a practical indicator aiding in improving the cost-effectiveness and reduce inequity of healthcare delivery for older adults in developing countries.

Women suffer but men die: survey data exploring whether this self-reported health paradox is real or an artefact of gender stereotypes

BACKGROUND

Despite consistently reporting poorer health, women universally outlive men. We examine whether gender differences in lived circumstances considered, and meaning attributed to SRH by women and men might explain this paradox.

METHODS

In an online survey 917 adults rated their health (SRH) and mental health (SRMH) and reflected upon what life experiences they considered in making their ratings. Descriptive findings were sex-disaggregated. The multiple experiences listed were then subject to factor analyses using principal components methods and orthogonal rotation.

RESULTS

Women reported poorer SRH and SRMH. They considered a wider range of circumstances, weighing all but self-confidence and behaviors as more important to SRH than did men. Two underlying components, psychosocial context and clinical status were identified overall. Physical health and pain were more important elements of men's clinical status and behaviors. Comparisons with others of the same age played a larger role in male psycho-social context. Two components also underpinned SRMH. These were clinical problems and psycho-social circumstances for which self-confidence was only important among men.

CONCLUSIONS

Women's and men's common interpretation of measures like SRH suggests that women's health disadvantage is neither artefactual nor determined by gendered meanings of measures and does not explain the paradox. SRH and SRMH captured social circumstances for all. Convergence of characteristics women and men consider as central to health is evidence of the dynamism of gender with evolving social norms. The remaining divergence speaks to persisting traditional male stereotypes.

Gender Gap in Unhealthy Life Expectancy: The Role of Education Among Adults Aged 45

Objectives: This paper examines the gender gap in unhealthy life expectancy across education levels and age in Spain to understand the extent to which the gender paradox exists over education and across ages. Methods: Death registrations and vital status were taken from the Spanish Statistical Office, while the three health measures (chronic conditions, bad-self rated health and cognitive impairment) from the 2019 European Health Interview Survey. We used Sullivan's method to compute unhealthy life expectancy by education level. We computed the gender and the education ratios of the proportion of unhealthy life years in each health measure by education and age. Results: At almost all ages and all education levels, women significantly lived longer but in poorer health than men. Marked gender differences are seen across most age-groups, particularly among the low educated. We detected greater health inequalities by education level for women (confirming the gender paradox) and a health gradient due to aging and across the health measures charting the disablement process. Conclusion: The new education distribution might improve the unhealthy life expectancy and might reduce the gender gap in the number of years spent in poor health.

A quantile frailty index without dichotomization

measures of health quantify the aging process of individuals. They should be interpretable, associated with future adverse outcomes, and straightforward to assemble. We use the rank-ordering of risk within a population to construct a quantile frailty index (QFI) that avoids dichotomization, is convenient and interpretable, and is associated with adverse outcomes. We show that the QFI outperforms previous frailty index (FI) measures on cross-sectional laboratory data (NHANES, CSHA, and ELSA). We construct the QFI by ranking the risk of individuals with respect to a reference population. Sex-specific reference populations narrow male-female FI differences as a function of age, and improve predictive performance. With a fixed reference population of 80-85 year olds, our QFI appears similar to earlier FI measures. With an age-matched reference population for each individual, we obtain a QFI that contains very little age information and that has similar predictive performance as other age-controlled FI measures. Adding age as an auxiliary variable leads to significantly better performance. We conclude that age should be controlled for when evaluating the predictive performance of summary measures of health. This is straight-forward to do with the QFI.

The potential for complex computational models of aging

The gradual accumulation of damage and dysregulation during the aging of living organisms can be quantified. Even so, the aging process is complex and has multiple interacting physiological scales - from the molecular to cellular to whole tissues. In the face of this complexity, we can significantly advance our understanding of aging with the use of computational models that simulate realistic individual trajectories of health as well as mortality. To do so, they must be systems-level models that incorporate interactions between measurable aspects of age-associated changes. To incorporate individual variability in the aging process, models must be stochastic. To be useful they should also be predictive, and so must be fit or parameterized by data from large populations of aging individuals. In this perspective, we outline where we have been, where we are, and where we hope to go with such computational models of aging. Our focus is on data-driven systems-level models, and on their great potential in aging research.

Insights from evolutionarily relevant models for human ageing

As the world confronts the health challenges of an ageing population, there has been dramatically increased interest in the science of ageing. This research has overwhelmingly focused on age-related disease, particularly in industrialized human populations and short-lived laboratory animal models. However, it has become clear that humans and long-lived primates age differently than many typical model organisms, and that many of the diseases causing death and disability in the developed world are greatly exacerbated by modern lifestyles. As such, research on how the human ageing process evolved is vital to understanding the origins of prolonged human lifespan and factors increasing vulnerability to degenerative disease. In this issue, we highlight emerging comparative research on primates, highlighting the physical, physiological, behavioural and cognitive processes of ageing. This work comprises data and theory on non-human primates, as well as under-represented data on humans living in small-scale societies, which help elucidate how environment shapes senescence. Component papers address (i) the critical processes that comprise senescence in long-lived primates; (ii) the social, ecological or individual characteristics that predict variation in the pace of ageing; and (iii) the complicated relationship between ageing trajectories and disease outcomes. Collectively, this work provides essential comparative, evolutionary data on ageing and demonstrates its unique potential to inform our understanding of the human ageing process. This article is part of the theme issue 'Evolution of the primate ageing process'.

Older women are frailer, but less often die then men: a prospective study of older hospitalized people

OBJECTIVES

The association between frailty, mortality and sex is complex, but a limited literature is available on this topic, particularly for older hospitalized patients. Therefore, the objective of our study was to prospectively evaluate sex differences in frailty, assessed by the Multidimensional Prognostic Index (MPI) and mortality, institutionalization, and re-hospitalization in an international cohort of older people admitted to hospital.

STUDY DESIGN

We used data from nine public hospitals in Europe and Australia, to evaluate sex differences in mortality, frailty and the risk of institutionalization and re-hospitalization, during one year of follow-up.

MAIN OUTCOME MEASURES

People aged 65 years or more admitted to hospital for an acute medical condition or for a relapse of a chronic disease were included. A standardized comprehensive geriatric assessment, which evaluated functional, nutritional, and cognitive status, risk of pressure sores, comorbidities, medications and co-habitation status, was used to calculate the MPI to measure frailty in all hospitalized older people. Data regarding mortality, institutionalization and re-hospitalization were also recorded for one year.

RESULTS

Altogether, 1140 hospitalized patients (mean age = 84.2 years; 694 women = 60.9%) were included. The one-year mortality rate was 33.2%. In multivariate analysis, adjusted for age, MPI score, centre and diagnosis at baseline, although women had higher MPI scores than men, the latter had higher in-hospital (odds ratio, OR = 2.26; 95% confidence intervals, CI = 1.27-4.01) and one-year post-discharge mortality (OR = 2.04; 95%CI = 1.50-2.79). Furthermore, men were less frequently institutionalized in a care home than female patients (OR = 0.55; 95%CI: 0.34-0.91), but they were also more frequently re-hospitalized (OR = 1.42; 95%CI: 1.06-1.91) during the year after hospital discharge.

CONCLUSION

Older hospitalized men were less frail, but experienced higher in-hospital and one-year mortality than women. Women were admitted more frequently to nursing homes and experienced a lower risk of re-hospitalization. These findings suggest important differences between the sexes and extends the 'male-female health-survival paradox' to acutely ill patient groups.

High intensity interval training improves physical performance in aged female mice: A comparison of mouse frailty assessment tools

Frailty syndrome increases the risk for disability and mortality, and is a major health concern amidst the geriatric shift in the population. High intensity interval training (HIIT), which couples bursts of vigorous activity interspersed with active recovery intervals, shows promise for the treatment of frailty. Here we compare and contrast five Fried physical phenotype and one deficit accumulation based mouse frailty assessment tools for identifying the impacts of HIIT on frailty and predicting functional capacity, underlying pathology, and survival in aged female mice. Our data reveal a 10-minute HIIT regimen administered 3-days-a-week for 8-weeks increased treadmill endurance, gait speed and maintained grip strength. One frailty tool identified a benefit of HIIT for frailty, but many were trending suggesting HIIT was beneficial for physical performance in these mice, but the 8-week timeframe may have been insufficient to induce frailty benefits. Finally, most frailty tools distinguished between surviving or non-surviving mice, whereas half correlated with functional capacity measured by nest building ability, and none correlated with underlying pathology. In summary, this study supports the ongoing development of mouse assessment tools as useful instruments for frailty research.

Genetically heterogeneous mice exhibit a female survival advantage that is age- and site-specific: Results from a large multi-site study

The female survival advantage is a robust characteristic of human longevity. However, underlying mechanisms are not understood, and rodent models exhibiting a female advantage are lacking. Here, we report that the genetically heterogeneous (UM-HET3) mice used by the National Institute on Aging Interventions Testing Program (ITP) are such a model. Analysis of age-specific survival of 3,690 control ITP mice revealed a female survival advantage paralleling that of humans. As in humans, the female advantage in mice was greatest in early adulthood, peaking around 350 days of age and diminishing progressively thereafter. This persistent finding was observed at three geographically distinct sites and in six separate cohorts over a 10-year period. Because males weigh more than females and bodyweight is often inversely related to lifespan, we examined sex differences in the relationship between bodyweight and survival. Although present in both sexes, the inverse relationship between bodyweight and longevity was much stronger in males, indicating that male mortality is more influenced by bodyweight than is female mortality. In addition, male survival varied more across site and cohort than female survival, suggesting greater resistance of females to environmental modulators of survival. Notably, at 24 months the relationship between bodyweight and longevity shifted from negative to positive in both sexes, similar to the human condition in advanced age. These results indicate that the UM-HET3 mouse models the human female survival advantage and provide evidence for greater resilience of females to modulators of survival.

Men Sustain Higher Dysregulation Levels Than Women Without Becoming Frail

The aging process differs in important ways between the sexes, with women living longer but at higher risk for frailty (the male-female health-survival paradox). The underlying biological mechanisms remain poorly understood, but may relate to sex differences in physiological dysregulation patterns. Here, using biomarkers from two longitudinal cohort studies (InCHIANTI and BLSA) and one cross-sectional survey (NHANES), we assess sex differences in trajectories of dysregulation globally and for five physiological systems: oxygen transport, electrolytes, hematopoiesis, lipids, and liver/kidney function. We found higher dysregulation levels in men, both globally and in the oxygen transport and hematopoietic systems (p < .001 for all), though differences for other systems were mixed (electrolytes) or absent (lipids and liver/kidney). There was no clear evidence for sex differences in rates of change in dysregulation with age. Although risk of frailty and mortality increase with dysregulation, there was no evidence for differences in these effects between sexes. These findings imply that the greater susceptibility of women to frailty is not simply due to a tolerance for higher dysregulation; rather, it may actually be men that have a greater tolerance for dysregulation, creating a male-female dysregulation-frailty paradox. However, the precise physiological mechanisms underlying the sex differences appear to be diffuse and hard to pin down.

How We Fall Apart: Similarities of Human Aging in 10 European Countries

We analyze human aging—understood as health deficit accumulation—for a panel of European individuals, using four waves of the Survey of Health, Aging and Retirement in Europe (SHARE data set) and constructing a health deficit index. Results from log-linear regressions suggest that, on average, elderly European men and women develop approximately 2.5 % more health deficits from one birthday to the next. In nonlinear regressions (akin to the Gompertz-Makeham model), however, we find much greater rates of aging and large differences between men and women as well as between countries. Interestingly, these differences follow a particular regularity (akin to the compensation effect of mortality) and suggest an age at which average health deficits converge for men and women and across countries. This age, which may be associated with human life span, is estimated as 102 ± 2.6 years.

The gender gap in mortality: How much is explained by behavior?

In developed countries, women are expected to live about 4-5 years longer than men. In this paper, we develop a novel approach to gauge the extent to which gender differences in longevity can be attributed to gender-specific preferences and health behavior. We set up a physiologically founded model of health deficit accumulation and calibrate it using recent insights from gerontology. From fitting life cycle health expenditure and life expectancy, we obtain estimates of the gender-specific preference parameters. We then perform the counterfactual experiment of endowing women with the preferences of men. In our benchmark scenario, this reduces the gender gap in life expectancy from 4.6 to 1.4 years. When we add gender-specific preferences for unhealthy consumption, the model can motivate up to 89 percent of the gender gap. Our theory offers also an economic explanation for why the gender gap declines with rising income.

The association between frailty, the metabolic syndrome, and mortality over the lifespan

Frailty and the metabolic syndrome are each associated with poor outcomes, but in very old people (90+ years) only frailty was associated with an increased mortality risk. We investigated the relationship between frailty, metabolic syndrome, and mortality risk, in younger (20-65 years) and older (65+ years) people. This is a secondary analysis of the US National Health and Nutrition Examination Survey (NHANES) datasets for 2003-2004 and 2005-2006, linked with mortality data up to 2011. The metabolic syndrome was defined using the International Diabetes Federation criteria. Frailty was operationalized using a 41-item frailty index (FI). Compared to the younger group (n = 6403), older adults (n = 2152) had both a higher FI (0.10 ± 0.00 vs. 0.22 ± 0.00, p < 0.001) and a greater prevalence of the metabolic syndrome (24.1 vs. 45.5%, p < 0.001). The metabolic syndrome and FI were correlated in younger people (r = 0.25, p < 0.001) but not in older people (r = 0.08, p < 0.1). In bivariate analyses, the FI predicted mortality risk in both age groups whereas the metabolic syndrome did so only in the younger group. In Cox models, adjusted for age, sex, race, education, and each other, the FI was associated with increased mortality risk at both ages (younger HR 1.05 (1.04-1.06); older HR 1.04 (1.03-1.04) whereas the metabolic syndrome did not contribute to mortality risk. The FI better predicted mortality than did the metabolic syndrome, regardless of age.

Sex differences in frailty: A systematic review and meta-analysis

BACKGROUND

It is a well-described clinical phenomenon that females live longer than males, yet tend to experience greater levels of co-morbidity and disability. Females can therefore be considered both more frail (because they have poorer health status) and less frail (because they have a lower risk of mortality). This systematic review aimed to determine whether this ageing paradox is demonstrated when the Frailty Index (FI) is used to measure frailty.

METHODS

Medline, EMBASE and CINAHL databases were searched for observational studies that measured FI and mortality in community-dwellers over 65years of age. In five-year age groups, meta-analysis determined the sex differences in mean FI (MD=mean FI_female-mean FI_male) and mortality rate.

RESULTS

Of 6482 articles screened, seven articles were included. Meta-analysis of data from five studies (37,426 participants) found that MD values were positive (p<0.001; MD range=0.02-0.06) in all age groups, indicating that females had higher FI scores than males at all ages. This finding was consistent across individual studies. Heterogeneity was high (I²=72.7%), reflecting methodological differences. Meta-analysis of mortality data (13,127 participants) showed that male mortality rates exceeded female mortality rates up until the 90 to 94-years age group. Individual studies reported higher mortality for males at each level of FI, and higher risk of death for males when controlling for age and FI.

CONCLUSIONS

The pattern of sex differences in the FI and mortality of older adults was consistent across populations and confirmed a 'male-female health-survival paradox'.

A comparison of health expectancies over two decades in England: results of the Cognitive Function and Ageing Study I and II

BACKGROUND

Whether rises in life expectancy are increases in good-quality years is of profound importance worldwide, with population ageing. We investigate how various health expectancies have changed in England between 1991 and 2011, with identical study design and methods in each decade.

METHODS

Baseline data from the Cognitive Function and Ageing Studies in populations aged 65 years or older in three geographically defined centres in England (Cambridgeshire, Newcastle, and Nottingham) provided prevalence estimates for three health measures: self-perceived health (defined as excellent-good, fair, or poor); cognitive impairment (defined as moderate-severe, mild, or none, as assessed by Mini-Mental State Examination score); and disability in activities of daily living (defined as none, mild, or moderate-severe). Health expectancies for the three regions combined were calculated by the Sullivan method, which applies the age-specific and sex-specific prevalence of the health measure to a standard life table for the same period.

FINDINGS

Between 1991 and 2011, gains in life expectancy at age 65 years (4·5 years for men and 3·6 years for women) were accompanied by equivalent gains in years free of any cognitive impairment (4·2 years [95% CI 4·2-4·3] for men and 4·4 years [4·3-4·5] for women) and decreased years with mild or moderate-severe cognitive impairment. Gains were also identified in years in excellent or good self-perceived health (3·8 years [95% CI 3·5-4·1] for men and 3·1 years [2·7-3·4] for women). Gains in disability-free years were much smaller than those in excellent-good self-perceived health or those free from cognitive impairment, especially for women (0·5 years [0·2-0·9] compared with 2·6 years [2·3-2·9] for men), mostly because of increased mild disability.

INTERPRETATION

During the past two decades in England, we report an absolute compression (ie, reduction) of cognitive impairment, a relative compression of self-perceived health (ie, proportion of life spent healthy is increasing), and dynamic equilibrium of disability (ie, less severe disability is increasing but more severe disability is not). Reasons for these patterns are unknown but might include increasing obesity during previous decades. Our findings have wide-ranging implications for health services and for extension of working life.

FUNDING

UK Medical Research Council.

Optimal Versus Realized Trajectories of Physiological Dysregulation in Aging and Their Relation to Sex-Specific Mortality Risk

While longitudinal changes in biomarker levels and their impact on health have been characterized for individual markers, little is known about how overall marker profiles may change during aging and affect mortality risk. We implemented the recently developed measure of physiological dysregulation based on the statistical distance of biomarker profiles in the framework of the stochastic process model of aging, using data on blood pressure, heart rate, cholesterol, glucose, hematocrit, body mass index, and mortality in the Framingham original cohort. This allowed us to evaluate how physiological dysregulation is related to different aging-related characteristics such as decline in stress resistance and adaptive capacity (which typically are not observed in the data and thus can be analyzed only indirectly), and, ultimately, to estimate how such dynamic relationships increase mortality risk with age. We found that physiological dysregulation increases with age; that increased dysregulation is associated with increased mortality, and increasingly so with age; and that, in most but not all cases, there is a decreasing ability to return quickly to baseline physiological state with age. We also revealed substantial sex differences in these processes, with women becoming dysregulated more quickly but with men showing a much greater sensitivity to dysregulation in terms of mortality risk.

Measuring frailty using self-report and test-based health measures

BACKGROUND

previously, frailty indices were constructed using mostly subjective health measures. The reporting error in this type of measure can have implications on the robustness of frailty findings.

OBJECTIVE

to examine whether frailty assessment differs when we construct frailty indices using solely self-reported or test-based health measures.

DESIGN

secondary analysis of data from The Irish LongituDinal study on Ageing (TILDA).

SUBJECTS AND METHODS

4,961 Irish residents (mean age: 61.9 ± 8.4; 54.2% women) over the age of 50 years who underwent a health assessment were included in this analysis. We constructed three frailty indices using 33 self-reported health measures (SRFI), 33 test-based health measures (TBFI) and all 66 measures combined (CFI). The 2-year follow-up outcomes examined were all-cause mortality, disability, hospitalisation and falls.

RESULTS

all three indices had a right-skewed distribution, an upper limit to frailty, a non-linear increase with age, and had a dose-response relationship with adverse outcomes. Levels of frailty were lower when self-reported items were used (SRFI: 0.12 ± 0.09; TBFI: 0.17 ± 0.15; CFI: 0.14 ± 0.13). Men had slightly higher frailty index scores than women when test-based measures were used (men: 0.17 ± 0.09; women: 0.16 ± 0.10). CFI had the strongest prediction for risk of adverse outcomes (ROC: 0.64-0.81), and age was not a significant predictor when it was included in the regression model.

CONCLUSIONS

except for sex differences, characteristics of frailty are similar regardless of whether self-reported or test-based measures are used exclusively to construct a frailty index. Where available, self-reported and test-based measures should be combined when trying to identify levels of frailty.

Cohort differences in the levels and trajectories of frailty among older people in England

Background

The level of frailty in the older population across age cohorts and how this changes is a factor in determining future care costs and may also influence the extent of socioeconomic and gender inequalities in frailty.

Methods

We model cohort-specific trajectories in frailty among the community dwelling population older than 50 years, using five waves (2002–2010) of the English Longitudinal Study of Ageing. We stratify our analysis by wealth and gender and use a frailty index, based on accumulation of ‘deficits’.

Results

For males and females between the ages of 50 and 70 in 2002, frailty trajectories for adjacent age cohorts converge. However, levels of frailty are higher in recent compared with earlier cohorts at the older ages (for cohorts aged over 70 in 2002). These cohort differences are largest in the poorest wealth group, while for the most affluent, frailty trajectories overlap across all adjacent cohorts suggesting no change across cohorts.

Conclusions

A key driver of the cohort differences in frailty that we observe is likely to be increased survival of frail individuals. Importantly, this paper illustrates that the social conditions experienced across the wealth distribution impacts on the rate of deficit accumulation in older populations. Our results on trajectories of frailty between 2002 and 2010 are pessimistic and, in the context of rising life expectancies, suggest that poorer older people in particular spend additional years of life in a frail state.

Standard laboratory tests to identify older adults at increased risk of death

BACKGROUND

Older adults are at an increased risk of death, but not all people of the same age have the same risk. Many methods identify frail people (that is, those at increased risk) but these often require time-consuming interactions with health care providers. We evaluated whether standard laboratory tests on their own, or added to a clinical frailty index (FI), could improve identification of older adults at increased risk of death.

METHODS

This is a secondary analysis of a prospective cohort study, where community dwelling and institutionalized participants in the Canadian Study of Health and Aging who also volunteered for blood collection (n = 1,013) were followed for up to six years. A standard FI (FI-CSHA) was constructed from data obtained during the clinical evaluation and a second, novel FI was constructed from laboratory data plus systolic and diastolic blood pressure measurements (FI-LAB). A combined FI included all items from each index. Predictive validity was tested using Cox proportional hazards analysis and discriminative ability by the area under receiver operating characteristic (ROC) curves.

RESULTS

Of 1,013 participants, 51.3% had died by six years. The mean baseline value of the FI-LAB was 0.27 (standard deviation 0.11; range 0.05 to 0.63), the FI-CSHA was 0.25 (0.11; 0.02 to 0.72), and the combined FI was 0.26 (0.09; 0.06 to 0.59). In an age- and sex-adjusted model, with each increment in the FI-LAB, the hazard ratios increased by 2.8% (95% confidence interval 1.02 to 1.04). The hazard ratios for the FI-CSHA and the combined FI were 1.02 (1.01 to 1.03) and 1.04 (1.03 to 1.05), respectively. The FI-LAB and FI-CSHA remained independently associated with death in the face of the other. The areas under the ROC curves were 0.72 for FI-LAB, 0.73 for FI-CSHA and 0.74 for the combined FI.

CONCLUSIONS

An FI based on routine laboratory data can identify older adults at increased risk of death. Additional evaluation of this approach in clinical settings is warranted.

Identifying common characteristics of frailty across seven scales

OBJECTIVES

To determine whether commonly used frailty scales exhibit shared characteristics when applied to a representative sample of middle-aged and older Europeans.

DESIGN

Secondary analysis of the Survey of Health, Ageing, and Retirement in Europe (SHARE).

SETTING

Eleven European countries.

PARTICIPANTS

Community-dwelling adults (N = 27,527; mean age 65.3 ± 10.5, 55% female).

MEASUREMENTS

Frailty was assessed using SHARE-operationalized versions of seven frailty scales: Edmonton Frail Scale, FRAIL scale, Groningen Frailty Indicator, frailty phenotype, Tilburg Frailty Indicator, a 70-item frailty index (FI), and a 44-item frailty index based on Comprehensive Geriatric Assessment.

RESULTS

All frailty scales demonstrated right-skewed density distributions. On all scales, frailty scores increased nonlinearly with age, between 1% (FRAIL) and 3.6% (FI) per year on a log scale. Frailty scores on all scales exhibited dose-response relationships with 5-year mortality. On all scales, women had higher frailty scores than men of the same age but demonstrated better survival than did men with the same frailty score. On all scales except the frailty phenotype, 99% of participants had scores below the scale's theoretical maximum.

CONCLUSION

On each frailty scale, frailty score increased nonlinearly with age, mortality risk increased with frailty score, and women had higher scores than men but demonstrated better survival. Each scale except the frailty phenotype demonstrated an upper limit to frailty below the scale's theoretical maximum. Across commonly used frailty scales, these characteristics are common in nature but differ in magnitude.

Pediatric mortality in males versus females in the United States, 1999-2008

OBJECTIVE

To evaluate whether differences between pediatric male and female mortality are due to differences in specific age ranges, specific disease categories, or differences in the risk of developing specific conditions versus the risk of dying once having developed the condition.

METHODS

Using 1999-2008 mortality data for all deaths of individuals <20 years of age from the Centers for Disease Control and Prevention's WONDER database, we calculated male-to-female relative risks (RRs), standardized to the 2000 US Census, by age and International Classification of Diseases, 10th revision (ICD-10), chapters. By using the Centers for Disease Control and Prevention's record of linked birth and infant death records between 1999 and 2007, we also calculated male-to-female RRs stratified by gestational age; and by using Surveillance, Epidemiology, and End Results cancer registries for 1999-2008, we calculated incidence and mortality RRs for the 7 leading types of cancer.

RESULTS

Males experience higher mortality rates in all age groups from birth to age 20 years (RR: 1.44; 95% confidence interval [CI]: 1.44-1.45) and among infant deaths in nearly all weekly gestational age strata (RR: 1.12; 95% CI: 1.11-1.12). Stratified by ICD-10 major disease categories, males experience higher mortality rates in 17 of 19 categories. For the 7 types of pediatric cancers, the overall pattern was similarly greater male incidence (RR: 1.13; 95% CI: 1.12-1.14), fatality rate (RR: 1.10; 95% CI: 1.07-1.13), and overall mortality (RR: 1.21; 1.18-1.25).

CONCLUSIONS

Under 20 years of age, males die more than females from a wide array of underlying conditions. The potential genetic and hormonal mechanisms for the mortality difference between males and females warrant investigation.

A limit to frailty in very old, community-dwelling people: a secondary analysis of the Chinese longitudinal health and longevity study

BACKGROUND

it has been observed that a frailty index (FI) is limited by the value of 0.7. Whether this holds in countries with higher mortality rates is not known.

OBJECTIVES

to test for and quantify a limit in very old Chinese adults and to relate mortality risk to the FI.

DESIGN

secondary analysis of four waves (1998, 2000, 2002 and 2005) of the Chinese Longitudinal Health and Longevity Study (CLHLS).

SUBJECTS

a total of 6,300 people from 22 of 31 provinces in China, aged 80-99 years at baseline and followed up to 7 years.

METHODS

an FI was calculated as the ratio of actual to 38 possible health deficits. Frequency distributions were used to evaluate the limit to the FI. Logistic regression and survival analysis were used to evaluate the relationship between the FI and mortality.

RESULTS

at each wave, a 99% submaximal limit to frailty was observed at FI = 0.7, despite consecutive losses to death. The death rate for those who were healthiest at baseline (i.e. those in whom the baseline FI = 0) increased from 0.18 at the 2-year follow-up to 0.69 by 7 years. At each wave, 100% mortality at 2 years was observed at FI close to 0.67. A baseline FI >0.45 was associated with 100% 7-year mortality.

CONCLUSIONS

a limit to frailty occurred with FI = 0.7 which was not exceeded at any age or in any wave. There appears to be a demonstrable limit to the number of health problems that people can tolerate.

Multidimensional health-transition patterns among a middle-aged and older population

AIM

Previous studies on health transition have focused on single-dimension outcomes and minimally evaluated heterogeneity. This study aimed to explore heterogeneous and multidimensional health-transition patterns on comorbidity, frailty and disability while examining the factors predicting different patterns of health transition.

METHODS

This study drew on data from a nationwide and longitudinally-followed sample of 5131 Taiwanese aged 50 years and older who were interviewed in 1996, 1999, 2003 and 2007. Latent class analysis (LCA) and multinomial logistic regression were applied to identify health-transition patterns and their predictors.

RESULTS

We identified six health-transition classes by applying LCA, including "persistently healthy", "well-managed comorbidity", "originally comorbid and gradually deteriorating to disability", "deteriorating gradually and died in late stage of the follow-up period", "deteriorating and died in middle stage of the follow-up period", and "originally comorbid and died in early stage of the follow-up period". Using the "well-managed comorbidity" class as the reference group, men had higher probabilities of being in the categories of dying in the follow-up period, but a lower risk of deteriorating to disability. Younger baseline age, higher education, having social engagement and non-smoking were predictors of "persistently healthy" and were associated with a lower risk of deteriorating to disability and death. Having a spouse and health examinations were associated with a lower risk of death, and also a lower probability of "persistently healthy".

CONCLUSIONS

Heterogeneous and multidimensional health-transition patterns exist in middle-aged and older populations. Several factors might have an effect on health-transition patterns.

Do gender, disability, and morbidity affect aging rate in the LLFS? Application of indices of cumulative deficits

We used an approach of cumulative deficits to evaluate the rate of aging in 4954 participants of the Long-Life Family Study (LLFS) recruited in the U.S. (Boston, New York, and Pittsburgh) and Denmark. We used an array of 85 health-related deficits covering major health dimensions including depression, cognition, morbidity, physical performance, and disability to construct several deficit indices (DIs) with overlapping and complementary sets of deficits to test robustness of the estimates. Our study shows that the DIs robustly characterize accelerated rates of aging irrespective of specific of deficits. When a wider spectrum of health dimensions is considered these rates are better approximated by quadratic law. Exponential rates are more characteristic for more severe health dimensions. The aging rates are the same for males and females. Individuals who contracted major diseases and those who were free of them exhibited the same aging rates as characterized by the DI constructed using mild deficits. Unlike health, disability can qualitatively alter the aging patterns of the LLFS participants. We report on systemic differences in health among the LLFS centenarians residing in New York and Boston. This study highlights importance of aggregated approaches to better understand systemic mechanisms of health deterioration in long-living individuals.

Nutritional status in the healthy longeval population from Sardinia (Italy)

OBJECTIVES

The aim of this study was to evaluate sex- and age-related variations of the nutritional status in the aged population of central Sardinia, a geographical area with a high frequency of long-lived people, particularly men.

DESIGN

The sample consisted of 200 subjects over 70 years of age (men: N= 100, age= 81.0 +/- 7.0 years; women: N= 100, age= 81.5 +/- 7.3 years).

SETTING

Orroli (central Sardinia, Italy).

MEASUREMENTS

Mini nutritional assessment (MNA) and bioelectrical impedance vector analysis (BIVA) were used to evaluate nutritional status and body composition.

RESULTS

The indicators revealed a generally good nutritional status. The MNA results (men: 24.6 +/- 2.2; women: 23.4 +/- 2.5) showed that 64.1% of the subjects had a normal nutritional status and only a small proportion (1.2%) could be classified as malnourished. BIVA showed that most subjects (74.2%) were normal, while the prevalence of low body cell mass was 10.7% and that of dehydration 11.2%. According to the MNA, the nutritional status was significantly better in the men. Almost three-quarters of the men (73.1%) were well nourished vs. half of the women (50.6%). A worsening of the nutritional status with age was observed. The proportion of malnourished individuals, as assessed by MNA, increased from 0% to 9.1% from 70-79 to > 90 years.

CONCLUSIONS

With respect to their contemporaries from other regions, the elderly of Orroli presented a better nutritional status, a similar worsening with age and generally higher sexual dimorphism.

Dynamics and heterogeneity in the process of human frailty and aging: evidence from the U.S. older adult population

OBJECTIVES

This study investigated the dynamics and heterogeneity of the frailty index (FI) conceived as a systemic indicator of biological aging in the community-dwelling older adult population in the United States.

METHODS

We used panel data on multiple birth cohorts from the Health and Retirement Survey 1993-2006 and growth curve models to estimate age trajectories of the FI and their differences by sex, race, and socioeconomic status (SES) within cohorts.

RESULTS

The FI for cohorts born before 1942 exhibit quadratic increases with age and accelerated increases in the accumulation of health deficits. More recent cohorts exhibit higher average levels of and rates of increment in the FI than their predecessors do at the same ages. Females, non-Whites, and individuals with low education and income exhibit greater degrees of physiological deregulation than their male, White, and high-SES counterparts at any age. Patterns of sex, race, and SES differentials in rates of aging vary across cohorts.

DISCUSSION

Adjusting for social behavioral factors, the analysis provides evidence for physiological differences in the aging process among recent cohorts of older adults, points to the need for biological explanations of female excess in general system damage, and reveals the insufficiency of any single mechanism for depicting the racial and SES differences in the process of physiological deterioration.