The emergence of extremely old people: the case of Japan

Surgical Fixation of Thoracolumbar Fractures in Patients Older than 80 Years

BACKGROUND AND OBJECTIVE

The global average life expectancy has been increasing steadily as the quality of healthcare continues to improve. However, there is a paucity of data looking at surgical fixation of thoracolumbar spine fractures in patients ≥80 years (super-elderly). Aim of this study is to look at whether there is higher rate of complications from surgical fixation of thoracolumbar fractures in this group of patients.

METHODS

We performed a retrospective study of patients who underwent surgical fixation of thoracolumbar spine fractures from 2019 to 2023. Patients were dichotomized into those who were 80 years old and above (super-elderly) and those younger than 80 years (control). Variables include sex, age, Charleston comorbidity index, presence of osteoporosis, length of hospital stay, complications, 6- and 12-months' implant status, and mortality. Incidence of revision surgery, rate of implant loosening, and mortality between the 2 groups were analyzed.

RESULTS

Total of 108 patients were included, 43 patients in the super-elderly group and 65 in the control group. Despite the super-elderly having a higher rate of osteoporosis and higher proportion of patients with severe comorbidities (P < .0001), there was no significant difference in the rate of implant loosening at 12 months' follow-up (P = .467) or all-cause mortality (P = .158). There were no significant differences between the 2 groups regarding revision surgery (P = .923) needed either.

CONCLUSION

The super-elderly had a higher incidence of osteoporosis and worse comorbidities, but there was no significant difference regarding implant complications, revision surgery required, or all-cause mortality. Hence, surgical fixation of thoracolumbar spine fractures in people older than 80 years should be considered despite their advanced age.

Symptom and Age Homophilies in SARS-CoV-2 Transmission Networks during the Early Phase of the Pandemic in Japan

Kanagawa and Hokkaido were affected by COVID-19 in the early stage of the pandemic. Japan's initial response included contact tracing and PCR analysis on anyone who was suspected of having been exposed to SARS-CoV-2. In this retrospective study, we analyzed publicly available COVID-19 registry data from Kanagawa and Hokkaido (n = 4392). Exponential random graph model (ERGM) network analysis was performed to examine demographic and symptomological homophilies. Age, symptomatic, and asymptomatic status homophilies were seen in both prefectures. Symptom homophilies suggest that nuanced genetic differences in the virus may affect its epithelial cell type range and can result in the diversity of symptoms seen in individuals infected by SARS-CoV-2. Environmental variables such as temperature and humidity may also play a role in the overall pathogenesis of the virus. A higher level of asymptomatic transmission was observed in Kanagawa. Moreover, patients who contracted the virus through secondary or tertiary contacts were shown to be asymptomatic more frequently than those who contracted it from primary cases. Additionally, most of the transmissions stopped at the primary and secondary levels. As expected, significant viral transmission was seen in healthcare settings.

A Cohort Comparison of Lifespan After Age 100 in Denmark and Sweden: Are Only the Oldest Getting Older?

Although Denmark and Sweden have close cultural and historical ties, lifespans for Danes have generally been lower than those of Swedes. Recent improvements in Danish mortality after a period of stagnation have led to the suspicion that there may be positive trends at the very high ages at death within that population and that these trends could be quite different from those observed in Sweden. Although the mean ages at death for Danish and Swedish centenarians have been relatively constant at about 102 years for the cohorts born 1870-1904, the oldest-old in Denmark have been getting older, but no evidence has suggested any increase in lifespan for Swedes. Using quantile regression, we show that Danish centenarian lifespans in the 90th percentile have been lengthening, with those in 94th percentile (6 % longest-lived individuals) having a trend that is statistically significant at the 5 % level. We demonstrate that the increase observed is not due to the increasing sizes of birth cohorts and thus must be due to improving survival among this select top tier. We postulate that this super-select group in Denmark is best able to take advantage of the factors driving mortality reduction, whereas the majority of centenarians are not.

Worldwide demography of centenarians

The global number of centenarians should strongly increase during the 21 st century. According to the Population Division of the United Nations it should reach more than 25 million people in 2100. To better understand the dynamics of the emergence and growth of the centenarian population, we focused on four European countries having long chronological series and high quality data about centenarians, Denmark, France, Sweden, and Switzerland, and Japan which has had the highest life expectancy at birth for several years. we analysed the emergence of the centenarian populations and their pace of growth in the wider context of the adult longevity revolution, as well as the trends in mortality level among these new populations. We found that out of the 5 countries studied, the decrease in mortality at age 100 for females who are leading the adult longevity revolution, seems to be interrupted in 4 countries, including in Japan. These results are in favour of the scenario of "compression of mortality", possibly limiting the future number of centenarians. However, previous studies have shown that demographic transitions are not linear and, after periods of interruption, trends can resume towards an always greater longevity.

Successful aging among Chinese near-centenarians and centenarians in Hong Kong: a multidimensional and interdisciplinary approach

OBJECTIVES

This study applied a multidimensional model on a continuum to examine successful aging (SA) and investigated whether SA is associated with biomedical and psychosocial-demographic factors among Hong Kong Chinese near-centenarians and centenarians.

METHOD

A cross-sectional data analysis was performed on a geographically representative sample of 120 near-centenarians and centenarians with an age range of 95-108 years. We developed an integrated and cumulative Successful Aging Index (SAI) based on participants' performance in four dimensions: (1) physical and functional health (PF), (2) psychological well-being and cognition (PC), (3) social engagement and family support (SF), (4) economic resources and financial security (EF). To examine the criterion validity of SAI, we conducted a multiple binary logistic regression with interviewer-rated health. A multiple regression model was ran to investigate the independent biomedical and psychosocial-demographic correlates of SAI.

RESULTS

Results show that only 5.8% of participants attained SA in all four dimensions. PF had the least achievers, whereas the proportion was the highest in PC. SAI was significantly associated with interviewer-rated health and a high level of high-density lipoprotein cholesterol. Living with family or friends, high level of optimism, fewer diseases, and barriers to social activities were independent predictors of SAI score.

CONCLUSION

In the light of the lack of consensus on the constituents and assessment of SA especially among very old adults, our findings add to the extant literature by underscoring the importance of the multidimensional nature and the utility of an integrated and cumulative-based assessment of SA at the extreme of longevity.

Impact of comorbidity index on morbidity and survival in non-small cell lung cancer

Background

The number of surgeries in older patients with comorbidities is constantly growing. The present study examined the impact of comorbidity on postoperative complications and long-term survival in patients with completely resected non-small cell cancer.

Methods

Between 2004 and 2008, 423 patients with non-small cell lung cancer underwent complete resection. A retrospective comparison of perioperative mortality, morbidity, Charlson comorbidity index (CCI), and postoperative length of hospital stay was performed.

Results

The number of patients with CCI 0, 1–2, and ≥3 was 226, 170 and 27, respectively. The 5-year overall survival was 88% among patients with CCI 0, and 84% in those with CCI ≥1 ( p = 0.05) in all pathological stages. The CCI 0 group had significantly better overall survival than CCI 0 group and 30 (15%) in the CCI ≥1 group ( p = 0.024). Length of stay was shorter in the CCI 0 group (11 ± 5 days) than in the CCI ≥1 group (15 ± 19 days, p = 0.015).

Conclusions

A high CCI correlated with higher postoperative morbidity and longer length of stay. We identified better a prognosis in patients with CCI 0 compared to those with CCI 1–2.

Economic and social implications of aging societies

The challenge of global population aging has been brought into sharper focus by the financial crisis of 2008. In particular, growing national debt has drawn government attention to two apparently conflicting priorities: the need to sustain public spending on pensions and health care versus the need to reduce budget deficits. A number of countries are consequently reconsidering their pension and health care provisions, which account for up to 40% of all government spending in advanced economies. Yet population aging is a global phenomenon that will continue to affect all regions of the world. By 2050 there will be the same number of old as young in the world, with 2 billion people aged 60 or over and another 2 billion under age 15, each group accounting for 21% of the world's population.

SURVIVAL OF CENTENARIANS IN JAPAN

The objective of the study was to explore the survival trends of centenarians in Japan. A cohort of centenarians born between 1881 and 1900 was analysed based on national census data, and the average life expectancy at 100 years of age, risk of death and maximum age were estimated. An analysis of covariance and a Cox regression analysis were performed to explore the factors associated with life expectancy and risk of death. The death rates in centenarians tended to decrease with birth year, and the average life expectancy from the age of 100 slightly increased at a rate of 0.013 years (95% CI: 0.007-0.019) by birth year in men and 0.026 in women. Women had a longer life expectancy than men, with a difference of 0.174 years (95% CI: 0.071-0.277) at birth year 1881 and increasing by 0.013 years per year thereafter. The risk of death in both sexes decreased significantly by birth year over the course of the period analysed, and the risk of death in men was 1.16 (95% CI: 1.14-1.19) times that of women. In women, death rates at every age significantly decreased with birth year over the course of the period analysed until age 104. However, this trend did not hold true for ages 105 and older. The average life expectancy of centenarians at the age of 100 in Japan increased by birth year in the 1881-1900 birth cohort. In addition, Japanese centenarians had the lowest death rates among several countries.

Age group performances in 100 km and 100 miles ultra-marathons

Improved performance has been reported for master runners (i.e. athletes older than 40 years) in both single marathons and single ultra-marathons. This study investigated performance trends of age group ultra-marathoners competing in all 100 km and 100 miles races held worldwide between 1971 and 2013. Changes in running speeds across years were investigated for the annual ten fastest 5-year age group finishers using linear, non-linear and multi-level regression analyses. In 100 km, running speed remained unchanged in women in 25–29 years, increased non-linearly in 30–34 to 55–59 years, and linearly in 60–64 years. In men, running speed increased non-linearly in 18–24 to 60–64 years and linearly in 65–69 to 75–79 years. In 100 miles, running speed increased in women linearly in 25–29 and 30–34 years, non-linearly in 35–39 to 45–49 years, and linearly in 50–54 and 55–59 years. For men, running speed increased linearly in 18–24 years, non-linearly in 25–29 to 45–49 years, and linearly in 50–54 to 65–69 years. Overall, the faster race times over the last 30 years are a result of all top ten finishers getting faster. These findings suggest that athletes in younger to middle age groups (i.e. 25–35 to 50–65 years depending upon sex and distance) have reached their limits due to a non-linear increase in running speed whereas runners in very young (i.e. younger than 25–35 years) and older age groups (i.e. older than 50–65 years) depending upon sex and distance might still improve their performance due to a linear increase in running speed.

Increasing Longevity and the New Demography of Death

The world is ageing at both an individual and population levels and population ageing is truly a global phenomenon, the only notable region of exception being sub-Saharan Africa, which remains relatively young in demographic terms. At an individual level, life expectancies at birth have increased at the global level from 47 years in the mid-20th century to around 70 years today and are expected to rise to 76 years by the mid-21st century. At the population level, the proportion of the world’s population aged 60 years and over has increased from 8 percent in the mid-20th century to 12 percent, and by 2050, it is expected to reach 21 percent. In Europe, ageing has continued at a slower rate, but with the emergence of increasing numbers of centenarians. This paper outlines the transition using data from England and Wales from a demography of young death in the mid-19th century to a demography of survival in the 20th century and on to the new demography of old death in the 21st century. The paper provides evidence that it is likely that ages at death will continue to increase, with more and more people reaching extreme old age. At the same time, it is likely that life expectancies at birth will continue to rise, taking life expectancy at birth in England and Wales to 100 years or more by the end of the 21st century. The new 21st century demography of death will lead to annual numbers of deaths far in excess of previous maxima.

Future prospects for longevity

It is acknowledged that the world is ageing at both the individual and population level. Life expectancies at birth have increased for males and females in the more developed economies across the 20th century. The 21st century is expected to see this development continue with life expectancies moving towards 100 years. This paper looks at the evidence for future increases in life expectancy and for the longest-lived to live even longer.

Physical independence and mortality at the extreme limit of life span: supercentenarians study in Japan

BACKGROUND

Prevention of disability is a major challenge in aging populations; however, the extent to which physical independence can be maintained toward the limit of human life span remains to be determined.

METHODS

We examined the health and functional status of 642 centenarians: 207 younger centenarians (age: 100-104 years), 351 semi-supercentenarians (age: 105-109 years), and 84 supercentenarians (age: >110 years). All-cause mortality was followed by means of an annual telephone or mailed survey.

RESULTS

Age-specific disability patterns revealed that the older the age group, the higher the proportion of those manifesting independence in activities of daily living at any given age of entry. Multiple logistic regression analysis identified male gender and better cognitive function as consistent determinants of physical independence across all age categories. In a longitudinal analysis, better physical function was significantly associated with survival advantage until the age of 110. However, mortality beyond that age was predicted neither by functional status nor biomedical measurements, indicating alternative trajectories of mortality at the highest ages.

CONCLUSIONS

These findings suggest that maintaining physical independence is a key feature of survival into extreme old age. Future studies illuminating genetic and environmental underpinnings of supercentenarians' phenotypes will provide invaluable opportunities not only to improve preventive strategies but also to test the central hypotheses of human aging.

Exploring the impact of climate on human longevity

The purpose of this study was to examine the impact of physical geographic factors and climate conditions on human longevity. The centenarian rate (CR) in 2005 was computed for Japan's 47 prefectures, whose geography and climate vary greatly. Several pathways, such as excess winter mortality, land use and agricultural production, possibly linking physical and climate factors with extreme longevity, were explored. The probability of becoming a centenarian varies significantly among the Japanese prefectures. In particular, the computation of CR(70) demonstrated that the actual probability for individuals 70 years old in 1975 of becoming centenarians in 2005 was 3 times higher, on average, in Okinawa, both for males and females, than in Japan as a whole. About three quarters of the variance in CR(70) for females and half for males is explained by the physical environment and land use, even when variations in the level of socio-economic status between prefectures are controlled. Our analysis highlighted two features which might have played an important role in the longevity observed in Okinawa. First, there is virtually no winter in Okinawa. For instance, the mean winter temperature observed in 2005 was 17.2°C. Second, today, there is almost no rice production in Okinawa compared to other parts of Japan. In the past, however, production was higher in Okinawa. If we consider that long term effects of harsh winters can contribute to the mortality differential in old age and if we consider that food availability in the first part of the 20th century was mainly dependent on local production, early 20th century birth cohorts in Okinawa clearly had different experiences in terms of winter conditions and in terms of food availability compared to their counterparts in other parts of Japan. This work confirms the impact of climate conditions on human longevity, but it fails to demonstrate a strong association between longevity and mountainous regions and/or air quality.

Excess male mortality and age-specific mortality trajectories under different mortality conditions: a lesson from the heat wave of summer 2003

INTRODUCTION

Our objective was to study the impact of an identical additional stress on male and female mortality with a quasi-experimental study design, using natural variations in summer mortality, including the massive heat wave that struck Europe in 2003.

MATERIAL AND METHODS

The summer daily mortality rates of the population aged 65 and over living in 16 European countries were computed by single age from 1998 to 2003. Using the method of Tukey, we established five categories summarizing the summer daily conditions of mortality (exceptionally high values, minor extremely high values, common values, minor extremely low values, and exceptionally low values).

RESULTS

Whatever the mortality conditions during the summer months, the mortality trajectories by age are exponential for both sexes: males die twice more than females at the age of 65 and their level of mortality linearly converges around the age of 97 to that of the females.

DISCUSSION

Being male remains a major risk factor of mortality during heat waves. This issue was missed by previous epidemiological studies because almost all of them focused only on the relative increase in mortality and not on the sex specific mortality rates which implies being able to estimate the population at risk.

Centenarians Today: New Insights on Selection from the 5-COOP Study

The number of oldest old grew tremendously over the past few decades. However, recent studies have disclosed that the pace of increase strongly varies among countries. The present study aims to specify the level of mortality selection among the nonagenarians and centenarians living currently in five low mortality countries, Denmark, France, Japan, Switzerland, and Sweden, part of the 5-Country Oldest Old Project (5-COOP). All data come from the Human Mortality Database, except for the number of centenarians living in Japan. We disclosed three levels of mortality selection, a milder level in Japan, a stronger level in Denmark and Sweden and an intermediary level in France and Switzerland. These divergences offer an opportunity to study the existence of a trade-off between the level of mortality selection and the functional health status of the oldest old survivors which will be seized by the 5-COOP project.

Mortality and morbidity trends: is there compression of morbidity?

OBJECTIVE

This paper reviews trends in mortality and morbidity to evaluate whether there has been a compression of morbidity.

METHODS

Review of recent research and analysis of recent data for the United States relating mortality change to the length of life without 1 of 4 major diseases or loss of mobility functioning.

RESULTS

Mortality declines have slowed down in the United States in recent years, especially for women. The prevalence of disease has increased. Age-specific prevalence of a number of risk factors representing physiological status has stayed relatively constant; where risks decline, increased usage of effective drugs is responsible. Mobility functioning has deteriorated. Length of life with disease and mobility functioning loss has increased between 1998 and 2008.

DISCUSSION

Empirical findings do not support recent compression of morbidity when morbidity is defined as major disease and mobility functioning loss.

Brain aging in the oldest-old

Nonagenarians and centenarians represent a quickly growing age group worldwide. In parallel, the prevalence of dementia increases substantially, but how to define dementia in this oldest-old age segment remains unclear. Although the idea that the risk of Alzheimer's disease (AD) decreases after age 90 has now been questioned, the oldest-old still represent a population relatively resistant to degenerative brain processes. Brain aging is characterised by the formation of neurofibrillary tangles (NFTs) and senile plaques (SPs) as well as neuronal and synaptic loss in both cognitively intact individuals and patients with AD. In nondemented cases NFTs are usually restricted to the hippocampal formation, whereas the progressive involvement of the association areas in the temporal neocortex parallels the development of overt clinical signs of dementia. In contrast, there is little correlation between the quantitative distribution of SP and AD severity. The pattern of lesion distribution and neuronal loss changes in extreme aging relative to the younger-old. In contrast to younger cases where dementia is mainly related to severe NFT formation within adjacent components of the medial and inferior aspects of the temporal cortex, oldest-old individuals display a preferential involvement of the anterior part of the CA1 field of the hippocampus whereas the inferior temporal and frontal association areas are relatively spared. This pattern suggests that both the extent of NFT development in the hippocampus as well as a displacement of subregional NFT distribution within the Cornu ammonis (CA) fields may be key determinants of dementia in the very old. Cortical association areas are relatively preserved. The progression of NFT formation across increasing cognitive impairment was significantly slower in nonagenarians and centenarians compared to younger cases in the CA1 field and entorhinal cortex. The total amount of amyloid and the neuronal loss in these regions were also significantly lower than those reported in younger AD cases. Overall, there is evidence that pathological substrates of cognitive deterioration in the oldest-old are different from those observed in the younger-old. Microvascular parameters such as mean capillary diameters may be key factors to consider for the prediction of cognitive decline in the oldest-old. Neuropathological particularities of the oldest-old may be related to "longevity-enabling" genes although little or nothing is known in this promising field of future research.

Insights from comparative analyses of aging in birds and mammals

Many laboratory models used in aging research are inappropriate for understanding senescence in mammals, including humans, because of fundamental differences in life history, maintenance in artificial environments, and selection for early aging and high reproductive rate. Comparative studies of senescence in birds and mammals reveal a broad range in rates of aging among a variety of taxa with similar physiology and patterns of development. These comparisons suggest that senescence is a shared property of all vertebrates with determinate growth, that the rate of senescence has been modified by evolution in response to the potential life span allowed by extrinsic mortality factors, and that most variation among species in the rate of senescence is independent of commonly ascribed causes of aging, such as oxidative damage. Individuals of potentially long-lived species, particularly birds, appear to maintain high condition to near the end of life. Because most individuals in natural populations of such species die of aging-related causes, these populations likely harbor little genetic variation for mechanisms that could extend life further, or these mechanisms are very costly. This, and the apparent evolutionary conservatism in the rate of increase in mortality with age, suggests that variation in the rate of senescence reflects fundamental changes in organism structure, likely associated with the rate of development, rather than physiological or biochemical processes influenced by a few genes. Understanding these evolved differences between long-lived and short-lived organisms would seem to be an essential foundation for designing therapeutic interventions with respect to human aging and longevity.

The relationship between longevity and healthy life expectancy

What is the relationship between longevity and health? Health expectancies were developed more than 30 years ago specifically to answer this question. It may therefore be the time to try to answer this question, though it is worth noting that the question implies a unidirectional relationship. Almost no one questions the positive association between health and longevity. It is expected that healthy, robust people will live, on average, longer than frail people. This heterogeneity in terms of robustness/frailty may explain the shape of the mortality trajectory with age, ie. the oldest old seem to follow a lower mortality schedule (Vaupel et al, 1979). On the other hand, many people wonder about the relationship between longevity and health. Are we living longer because we are in better health? Are we living longer in good health? Or are we merely surviving longer whatever our health status? In other words, can we live in good health as long as we can survive? And this is exactly the purpose of health expectancies: monitoring how long people live in various health statuses (Sanders, 1964; Sullivan, 1971; Robine et al, 2003a).

Life at the extreme limit: phenotypic characteristics of supercentenarians in Okinawa

BACKGROUND

As elite representatives of the rapidly increasing "oldest-old" population, centenarians have become an important model population for understanding human aging. However, as we are beginning to understand more about this important phenotype, another demographic group of even more elite survivors is emerging-so-called "supercentenarians" or those who survive 110-plus years. Little is known about these exceptional survivors.

METHODS

We assessed the Okinawa Centenarian Study (OCS) database for all information on supercentenarians. The database includes dates of birth and year of death for all residents of Okinawa 99 years old or older and a yearly geriatric assessment of all centenarians who consented, enabling prospective study of age-related traits. Of 20 potential supercentenarians identified, 15 had agreed to participate in the OCS interview, physical examination, and blood draw. Of these 15, 12 (3 men and 9 women) met our age validation criteria and were accepted as supercentenarians. Phenotypic variables studied include medical and social history, activities of daily living (ADLs), and clinical phenotypes (physiology, hematology, biochemistry, and immunology).

RESULTS

Age at death ranged from 110 to 112 years. The majority of supercentenarians had minimal clinically apparent disease until late in life, with cataracts (42%) and fractures (33%) being common and coronary heart disease (8%), stroke (8%), cancer (0%), and diabetes (0%) rare or not evident on clinical examination. Functionally, most supercentenarians were independent in ADLs at age 100 years, and few were institutionalized before the age of 105 years. Most had normal clinical parameters at age 100 years, but by age 105 exhibited multiple clinical markers of frailty coincident with a rapid ADL decline.

CONCLUSION

Supercentenarians displayed an exceptionally healthy aging phenotype where clinically apparent major chronic diseases and disabilities were markedly delayed, often beyond age 100. They had little clinical history of cardiovascular disease and reported no history of cancer or diabetes. This phenotype is consistent with a more elite phenotype than has been observed in prior studies of centenarians. The genetic and environmental antecedents of this exceptionally healthy aging phenotype deserve further study.

They really are that old: a validation study of centenarian prevalence in Okinawa

Long-lived individuals, such as centenarians, may harbor genetic or environmental advantages important for healthy aging. Populations with high prevalence of such individuals offer fertile ground for such research. However, precise phenotypes are required, particularly accurate age. Okinawa has among the world's highest reported prevalence of centenarians but, despite extensive study, no systematic validation of centenarian prevalence has been published. Therefore, we performed comprehensive age validation of a subset (8%) of the total centenarian population and assessed the reliability of the age registration system. Self-reported age was validated with several common methods and found to correlate well with documented age. Demographic methods, including assessment of age heaping, maximum age at death, centenarian proportions, and male to female ratios of centenarians indicate that the age registration system is reliable. We conclude that the high reported centenarian prevalence in Okinawa is valid and warrants further study for its genetic and environmental correlates.

Morphological substrates of cognitive decline in nonagenarians and centenarians: a new paradigm?

Brain aging is characterized by the formation of neurofibrillary tangles (NFT) and senile plaques (SP) in both cognitively intact individuals and patients with Alzheimer's disease (AD). The ubiquitous presence of these lesions and the steady increase of the prevalence of dementia up to 85 years have strongly supported a continuum between normal brain aging and AD. In this context, the study of nonagenarians and centenarians could provide key informations about the characteristics of extreme aging. We provide here a detailed review of currently available neuropathological data in very old individuals and critically discuss the patterns of NFT, SP and neuronal loss distribution as a function of age. In younger cohorts, NFTs are usually restricted to hippocampal formation, whereas clinical signs of dementia appear when temporal neocortex is involved. SPs would not be a specific marker of cognitive impairment as no correlation was found between their quantitative distribution and AD severity. The low rate of AD lesions even in severe AD as well as the weakness of clinicopathological correlations reported in the oldest-old indicate that AD pathology is not a mandatory phenomenon of increasing chronological age. Our recent stereological observations of hippocampal microvasculature in oldest-old cases challenge the traditional lesional model by revealing that mean capillary diameters is an important structural determinant of cognition in this age group.

Age related variation of salivary testosterone values in healthy Japanese males

OBJECTIVE

We examined age associated variation in salivary testosterone values among Japanese males as well as anthropometric measurements.

METHODS

Salivary samples were collected in pretreated sodium azide treated tubes. The first series: 15-79-year-old males (n = 99); two morning and two evening samples were collected at home for two days. The second series: 90-year-old males (n = 29); one morning sample was collected. Testosterone values were determined using an iodine125-based radioimmunoassay kit modified for saliva.

RESULTS

Results show 1) a significant decrease in salivary testosterone values from 20s to 40s and older, 2) no significant decline after 40 through 90 years old, 3) no significant age-related differences in the degree of intraindividual diurnal fluctuation across age groups of 40-70s, and 4) higher BMI is associated with the lower salivary testosterone among 40-70s.

CONCLUSIONS

These results suggest that neither a constant decrease of salivary testosterone values or markedly reduced intraindividual fluctations are universal aspects of aging. Older males may maintain relatively high testosterone levels compared to younger men and a relatively 'robust' neuroendocrinological system.

Predicting and preventing adverse drug reactions in the very old

The size of the elderly population has been increasing steadily for several years. Individuals in this age group often have several concomitant diseases that require treatment with multiple medications. These drugs, for various reasons and especially as a consequence of potential accumulation, may be associated with adverse reactions. Of the numerous factors that can favour the occurrence of these adverse drug reactions, the most important are the pathophysiological consequences of aging, particularly as these apply to the very old. Although absorption of drugs is not usually reduced in the elderly, diffusion, distribution and particularly elimination decline with age. Furthermore, while hepatic metabolic function is fairly normal, renal function is usually markedly depressed in very old individuals, and this can translate into clinical consequences if it is not taken into account. This is why, before administration of any drug in the elderly, evaluation of glomerular filtration rate is essential. Validated estimations such as those obtained from the classical Cockcroft-Gault formula or from more recent methodologies are required. In addition to reductions in various organ functions, factors connected with very old age such as frailty, falls, abnormal sensitivity to medications and polypathology, all of which tend to be more common in the last years of life, all directly impact on adverse drug reaction occurrence. Given these characteristics of the elderly population, the best way to reduce the prevalence of adverse drug reactions in this group is to limit drug prescription to essential medications, make sure that use of prescribed agents is clearly explained to the patient, give drugs for as short a period as possible, and periodically re-evaluate all use of drugs in the elderly.

Evaluation of Mini-Nutritional Assessment for Japanese frail elderly

OBJECTIVE

We evaluated the Mini-Nutritional Assessment (MNA) test and the short-form MNA as screening tools for malnutrition in the Japanese elderly population.

METHODS

A cross-sectional study of 226 elderly Japanese patients (78.6 +/- 0.5 y of age, mean +/- standard deviation; 67 men and 159 women) in various settings was carried out. Nutritional assessment included MNA, anthropometric measurements, and biochemical markers.

RESULTS

According to the original cutoff point of the full MNA, 19.9% of those assessed were malnourished, 58.0% were at risk of malnutrition, and 22.1% were well nourished. Significant correlations were found between full MNA scores and age (r = -0.14), body mass index (r = 0.59), serum albumin (r = 0.60), total cholesterol (r = 0.36), midarm circumference (r = 0.50), and triceps skinfold (r = 0.37). The sensitivity and specificity of the full MNA score (< 17) for hypoalbuminemia were 0.810 and 0.860, respectively. With a cutoff point lower than 18, sensitivity and specificity hypoalbuminemia were 0.857 and 0.815, respectively. Using a short-form MNA score 12 and higher as normal, its sensitivity and specificity for predicting undernutrition were 0.859 and 0.840, respectively.

CONCLUSIONS

The full and short forms of the MNA were useful tools to identify elderly Japanese patients with malnutrition or risk of malnutrition. However, the full MNA cutoff point for malnutrition should be modulated for this population.

Three dimensions of the survival curve: horizontalization, verticalization, and longevity extension

Three dimensions of the survival curve have been developed: (1) "horizontalization," which corresponds to how long a cohort and how many survivors can live before aging-related deaths significantly decrease the proportion of survivors; (2) "verticalization," which corresponds to how concentrated aging-related ("normal") deaths are around the modal age at death (M); and (3) "longevity extension," which corresponds to how far the highest normal life durations can exceed M. Our study shows that the degree of horizontalization increased relatively less than the degree of verticalization in Hong Kong from 1976 to 2001. After age normalization, the highest normal life durations moved closer to M, implying that the increase in human longevity is meeting some resistance.

Nonagenarians and centenarians in Switzerland, 1860-2001: a demographic analysis

STUDY OBJECTIVE

To explore the rapid rise of the extremely old population, showing the magnitude of the increase and identifying demographic mechanisms underlying this increase.

DESIGN

Demographic analysis using census data, yearly population estimates, and mortality statistics.

SETTING

Switzerland 1860-2001.

MAIN RESULTS

Indicators suggest a strong increase in the number of nonagenarians and centenarians in Switzerland as compared with other countries. The increase is mostly attributable to the decline in mortality after age 80. This decline started in the 1950s.

CONCLUSION

Nonagenarians and centenarians constitute a new population, which became sizeable after 1950 in Switzerland. There is a need to monitor this population with appropriate demographic and epidemiological indicators.

L’évolution de la longévité à Okinawa, 1921-2000

Toutes les données démographiques montrent que la longévité est exceptionnelle à Okinawa, même par comparaison avec le Japon. L’espérance de vie des hommes s’y compare à celle de tout le pays, et les femmes y jouissent de 1,4 année de plus que l’ensemble de leurs compatriotes. De la sorte, Okinawa dépasse 86 années d’espérance de vie, seuil considéré comme une limite maximale pour l’espèce humaine il y a encore deux décennies. Si l’on compare la prévalence des centenaires, on en compte 40 pour 100 000 habitants à Okinawa, mais 15 au Japon. Takahashi (1993) est le seul démographe à avoir mis cette situation exceptionnelle en évidence, mais des chercheurs d’autres disciplines ont ouvert de nombreuses pistes explicatives pour en rendre compte. Ils mettent en avant certaines caractéristiques génétiques, une moindre consommation de sel, mais aussi une alimentation plus riche en protéines animales, un climat plus doux, propice à un plus haut niveau d’activité tout au long de l’année, la considération plus grande accordée aux personnes âgées au sein de la société et, de façon plus globale, un style de vie plus traditionnel. Toutefois, dès la fin des années 1980, on a décelé à Okinawa une moindre amélioration des risques de décéder pour les jeunes adultes. Concrètement, notre analyse des tables de mortalité met en évidence un croisement des taux de mortalité : face au risque de mourir, la population d’Okinawa semble ainsi se diviser en deux groupes, les générations nées avant ou pendant la Seconde Guerre mondiale et celles qui sont nées après. La situation des premières est nettement meilleure que celle de l’ensemble de la population japonaise, la situation des secondes moins favorable. Nous tentons de saisir les causes de ce croisement de mortalité et ses conséquences possibles pour l’évolution de la longévité à Okinawa.

Artificial environments and an aging population: designing for age-related functional losses

Over the past century there has been a large and continuing increase in the frequency of persons aged over 65 years; particularly those aged over 100 years. During the 21st century the number of persons over 100 years will continue to increase. This will occur at such a rapid rate that the 21st century may one day be called the century of centenarians. Frailty and disability secondary to senescence, disease, and trauma have accompanied old age (often defined as age 65 and over) as far back as recorded history. However, during the 20th century, age, frailty, disability, and chronic degenerative diseases have been decoupled to some extant in the most long-lived human populations. Until recently, there was little need to design artificial environments for the unique needs of the elderly due to their low representation in most national populations. Today that need is increasing in concert with the number of persons aged 65 and older. The purpose of this review is to suggest areas wherein physiological anthropologists may have an opportunity to contribute to design trends for this rapidly increasing aging population. Major considerations for design of environments for the elderly are based upon altering the environment to accommodate their declining visual, auditory, and kinesthetic senses, thereby enhancing their declining faculties and improving their autonomy, independence, and self perceptions of well-being. To date most design considerations have been directed toward improving environments for those suffering from Alzheimer's disease or residing within assisted living facilities. Many such design improvements also may be effective in improving life satisfaction and functional abilities of the non-institutionalized elderly.

Demography of human supercentenarians

An international committee of demographers has created a carefully documented list of worldwide living supercentenarians (> or =110 years old) that has been published by the Los Angeles Gerontology Research Group on its web site and updated on a weekly basis for the past 6 years [see "snapshot" for the year 2003 in the Appendix]. What can be learned by studying this distinguished group of individuals? Also, what are the implications for understanding the fundamental biological limits to human longevity and maximum life span? Our conclusion: Although everyone agrees that average life expectancy has systematically advanced linearly over the last century, it is not realistic to expect that this pace can continue indefinitely. Our data suggest that, without the invention of some new unknown form of medical breakthrough, the Guinness Book of World Records benchmark established by French woman Jeanne Calment of 122 years, set back in 1997, will be exceedingly difficult to break in our lifetime.

Looking Forward to a General Theory on Population Aging

The main theories on population aging based on recent data on human longevity, life expectancy, morbidity changes, disability trends, and mortality decrease are presented and discussed within their own geographic, cultural, socioeconomic, and medical contexts. The complex interactions between all these components do not facilitate trend forecasting of aging population (healthy aging versus disability pandemic). In the context of population aging, four elements were introduced with their implications: 1) an increase in the survival rates of sick persons, which would explain the expansion of morbidity, 2) a control of the progression of chronic diseases, which would explain a subtle equilibrium between the decrease in mortality and the increase in disability, 3) an improvement of the health status and health behaviors of new cohorts of elderly people, which would explain the compression of morbidity, and eventually 4) an emergence of very old and frail populations, which would explain a new expansion of morbidity. Obviously, all these elements coexist today, and future trend scenarios-expansion or compression of disability-depend on their respective weights leading to the need of elaborating "a general theory on population aging." This theory has to be based on a world harmonization of functional decline measurements and a periodic "International Aging Survey" to monitor global aging through a sample of carefully selected countries.