Narrow Results

Section “Introduction and Historical Background” of this chapter briefly reviews the literature on medical spending, which suggests that health expenditures began small but steadily increased throughout history (from 1% to 4% of GDP), then began to increase rapidly among wealthier developed countries after 1950. Section “Measurement: Temporal, Spatial and Administrative Units of Observation” examines temporal and spatial dimensions of measurement, which suggest that the evolution of global health expenditures may be best observed by tracking health expenditures as a share of GDP over decades. Nominal and real per capita amounts are subject to distortions created by lags and currency valuation. Months and years are too short a span, while persons, households and provinces are too small. Section “Lags, Business Cycles, and Growth Trends” covers growth in the components of health expenditures (population, income, inflation, excess due to technology and other factors). A model of national health expenditure decisions over time is presented and used to explain empirical findings of varying distributed lag responses to macroeconomic growth and development. Section “Forecasting National and Global Health Expenditure Trends” considers the methods and accuracy of national health expenditure forecasting. Section “Aging, Health Expenditures and Fiscal Burdens” addresses some problems of variable identification, with specific applications to population aging and the aggregate fiscal burden of care for the elderly. Section “Global Health Spending Patterns 1850–1955 and 1960–2075” discusses the sustainability of current trends and the boundaries between long-term care, retirement and medical expenditures. It concludes by proposing that rising longevity and medical costs are best viewed as aspects of a process of economic and human development transforming the 20th and 21st centuries, rather than as isolated phenomena. The six sections each conclude with a discussion of policy implications, even the most technical sections regarding measurement, aggregation and lags, where the policy implications may not be immediately apparent. While nominal policies are publicly stated, it is often these “technical details” regarding boundary definition, timing and measurement that show how policy actually operates, that shape public opinion, and that drive future financial decisions.

Ti–6Al–2Sn–4Zr–2Mo (Ti-6242), a near-$\alpha$ titanium alloy explicitly designed for high-temperature applications, consists of a martensitic structure after selective laser melting (SLM). However, martensite is thermally unstable and thus adverse to the long-term service at high temperatures. Hence, understanding martensite decomposition is a high priority for seeking post-heat treatment for SLMed Ti-6242. Besides, compared to the room-temperature titanium alloys like Ti–6Al–4V, aging treatment is indispensable to high-temperature near-$\alpha$ titanium alloys so that their microstructures and mechanical properties are pre-stabilized before working at elevated temperatures. Therefore, the aging response of the material is another concern of this study. To elaborate the two concerns, SLMed Ti-6242 was first isothermally annealed at 650${}^{\circ }\mathrm{\text{C}}\le T\le 1025^{\circ }$C and then water-quenched to room temperature, followed by standard aging at 595${}^{\circ }$C. The microstructure analysis revealed a temperature-dependent martensite decomposition, which proceeded sluggishly at $T\le 700^{\circ }$C despite a long duration but rapidly transformed into lamellar $\alpha +\beta$ above the martensite transition zone (770${}^{\circ }\mathrm{\text{C}}\le T\le 800^{\circ }$C). As heating to $T>\beta -\mathrm{\text{transus}}(993^{\circ }$C), it produced a coarse microstructure containing new martensites formed in water quenching. The subsequent mechanical testing indicated that SLM-built Ti-6242 is excellent in terms of both room- and high-temperature tensile properties, with around 1400 MPa (UTS)$+$5% elongation and 1150 MPa (UTS)$+$10% elongation, respectively. However, the combination of water quenching and aging embrittled the as-built material severely.

Laboratory natural selection for rapid development and extremely early reproduction in Drosophila melanogaster was applied to ten independent populations from a known stock phylogeny. These populations, designated ACB and ACO, were contrasted with ten ancestor/ control populations (CB and CO) and five long-established baseline (B) populations. After 100 generations of selection, these “accelerated” populations had evolved a total generation time of under eight days, compared with 12 days in their controls. Reduced pre-adult viability and pupation height were previously reported as costs of rapid development. Here we report that these populations also evolved substantially reduced body size (as measured by thorax length and dry weight), reduced early- and late-life female fecundity, reduced starvation resistance, and reduced longevity, while gaining only in the age of peak fecundity. These results suggest the strong and pervasive negative influence of selection for fast development and early fertility on fitness components expressed later in life. This syndrome of effects illuminates the direct connection of the preadult and adult stages through energetic trade-offs. We also discuss the potential role of antagonistic pleiotropy and mutation accumulation in the evolution of senescence in these populations, and the difficulty of dissecting the role of aging from the direct impact of miniaturization observed in the accelerated populations.

The purpose of this study was to evaluate the effects of diosgenin on the D-galactose-induced cerebral cortical widely dispersed apoptosis. Male 12-week-old Wistar rats were divided into four groups: Control (1mg/kg/day of saline, i.p.), DD0 (150mg/kg/day of D-galactose, i.p.), DD10, and DD50 (D-galactose$+10$ or 50mg/kg/day of diosgenin orally). After eight weeks, histopathological analysis, positive TUNEL and Western blotting assays were performed on the excised cerebral cortex from all four groups. The TUNEL-positive apoptotic cells, the components of Fas pathway (Fas, FADD, active caspase-8 and active caspase-3), and mitochondria pathway (t-Bid, Bax, cytochrome $c$, active caspase-9 and active caspase-3) were increased in the DD0 group compared with the control group, whereas they were decreased in the DD50 group. The components of survival pathway (p-Bad, Bcl-2, Bcl-xL, IGF-1, p-PI3K and p-AKT) were increased in the DD50 group compared to the control group, whereas the levels of Bcl-xL, p-PI3K, and p-AKT were also compensatorily increased in the DD0 group compared to the control group. Taken together, diosgenin suppressed D-galactose-induced neuronal Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced the Bcl-2 family associated pro-survival and IGF-1-PI3K-AKT survival pathways, which might provide neuroprotective effects of diosgenin for prevention of the D-galactose-induced aging brain.

This study attempted to access the neuroprotective effect of diosgenin on the senescent mice induced by d-galactose (D-gal). The mice in the experiments were orally administered with diosgenin (1, 5, 25 and 125 mg/kg), for four weeks from the sixth week. The learning and memory abilities of the mice in Morris water maze test and the mechanism involved in the neuroprotective effect of diosgenin on the mice brain tissue were investigated.

Diosgenin (5, 25 and 125 mg/kg, p.o.) showed significantly improved learning and memory abilities in Morris water maze test compared to D-gal treated mice (200 mg/kg, ten weeks). Diosgenin also increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and decreased the malondialdehyde (MDA) level in the brain of D-gal treated mice.

These results indicated that diosgenin has the potential to be a useful treatment for cognitive impairment. In addition, the memory enhancing effect of diosgenin may be partly mediated via enhancing endogenous antioxidant enzymatic activities.

One of the important areas of heart research is investigating how heart activity changes during aging. In this research, we employed complexity-based techniques to analyze how heart activity varies based on the age of subjects. For this purpose, the heart rate variability (HRV) of 54 healthy subjects (30 M, 24 F, 28.5–76 years old) in three different age groups was analyzed using fractal theory, sample entropy, and approximate entropy. We showed that the fractal dimension, sample entropy, and approximate entropy of the RR interval time series (as HRV) are related to the age of the subjects. In other words, as subjects get older, the complexity of their RR interval time series decreases. Therefore, we decoded the variations in HRV during aging. The method of analysis that was employed in this research can be used to analyze the variations of other physiological signals (e.g. Electroencephalogram (EEG) signals) during aging.

It is known that heart activity changes during aging. In this paper, we evaluated alterations of heart activity from the complexity point of view. We analyzed the variations of heart rate of patients with congestive heart failure that are categorized into four different age groups, namely 30–39, 50–59, 60–69, and 70–79 years old. For this purpose, we employed three complexity measures that include fractal dimension, sample entropy, and approximate entropy. The results showed that the trend of increment of subjects’ age is reflected in the trend of increment of the complexity of heart rate variability (HRV) since the values of fractal dimension, approximate entropy, and sample entropy increase as subjects get older. The analysis of the complexity of other physiological signals can be further considered to investigate the variations of activity of other organs due to aging.

The purpose of this study was to evaluate the effects of Baduanjin exercise on oxidative stress, antioxidant status and quality of life in middle-aged women. A quasi-experimental design was adopted. Subjects were 31 middle-aged women. Subjects completed a supervised and standardized Baduanjin exercise program 3 times a week for 12 weeks. Malondialdehyde (MDA) level was measured and determined by using a spectrophotometer for oxidative stress. The superoxide dismutase (SOD) was measured for the antioxidant status. A 36-item Short Form Health Survey (SF-36) was used to evaluate changes in quality of life. All outcome measures were collected before intervention and at the end of a 12-week intervention. The results suggest that there are significant differences in serum SOD level with Baduanjin exercise. SOD level was significantly increased after exercise (p < 0.05). Baduanjin exercise contributed significantly to antioxidant status on these samples. However, a reduction in MDA level was observed. The t-test value was 2.03 with a p-value of 0.052. The changes may be meaningful at a 5% level. There are significant improvements in quality of life after the exercise program. Subjects had greater improvements in 4 dimensions of SF-36, namely physical function, body pain, social function and general mental health (p < 0.05). In conclusion, Baduanjin exercise has beneficial effects on improving quality of life, increasing antioxidant enzymes and reducing oxidative stress in middle-aged women. Reduction of MDA level may be more attributable to the increase in the antioxidant enzyme SOD.

Precipitation hardening is an effective way to improve the functional stability of NiTi shape memory alloys. The precipitates, mainly Ni₄Ti₃, could be introduced by aging treatment in Ni-rich NiTi alloys. However, the presence of Ni₄Ti₃ precipitates could disturb the transformation behavior, resulting in the multi-stage martensitic transformation (MMT). With the presence of MMT, it is difficult to control the transformation behavior, and thus limits the applicability of NiTi alloys. In this work, previous efforts on explaining the observed MMT are summarized. The difficulties in developing a unified explanation are discussed, and a possible way to avoid the MMT is proposed.

The medicinal plant Rhodiola crenulata grows at high altitudes in the Arctic and mountainous regions and is commonly used in phytotherapy in Eastern European and Asian countries. In the present study, we investigated the anti-apoptotic effect of Rhodiola crenulata and its neuroprotective mechanism of action in a rat model of D-galactose-induced aging. Two groups of twelve-week-old male Wistar rats received a daily injection of D-galactose (150mg/kg/day, i.p.) and orally administered Rhodiola crenulata (0, 248mg/kg/day) for eight weeks, while a control group received a saline injection (1ml/kg/day, i.p.). We examined apoptosis in the cortex and hippocampus of three groups of rats based on a terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling (TUNEL) positive assay. The expression levels of apoptotic and anti-apoptotic proteins in excised brains were analyzed by Western blotting. Our findings indicated that D-galactose caused marked neuronal apoptosis via activation of both extrinsic-dependent and mitochondrial-dependent apoptotic pathways. When compared to the control group, the protein levels of Fas receptor, Fas ligand, Fas-associated death domain (FADD), and activated caspase-8 (Fas-dependent apoptotic pathways), as well as those of t-Bid, Bax, cytochrome $c$, activated caspase-9, and activated caspase-3 (mitochondrial-dependent apoptotic pathways), were significantly increased in the D-galactose treated group. In addition, D-galactose impaired the phosphorylation of PI3K/Akt, an important survival signaling event in neurons. Rhodiola crenulata, however, protected against all these neurotoxicities in aging brains. The present study suggests that neuronal survival promoted by Rhodiola crenulata may be a potentially effective method to enhance the resistance of neurons to age-related disorders.

It is known that aging affects neuroplasticity. On the other hand, neuroplasticity can be studied by analyzing the electroencephalogram (EEG) signal. An important challenge in brain research is to study the variations of neuroplasticity during aging for patients suffering from epilepsy. This study investigates the variations of the complexity of EEG signal during aging for patients with epilepsy. For this purpose, we employed fractal dimension as an indicator of process complexity. We classified the subjects in different age groups and computed the fractal dimension of their EEG signals. Our investigations showed that as patients get older, their EEG signal will be more complex. The method of investigation that has been used in this study can be further employed to study the variations of EEG signal in case of other brain disorders during aging.

Different time-dependent mechanisms such as creep, environmental surface oxidation or internal material degradation due to aging and irradiation will subject structures to the possibility of premature failures. In this paper a micro-scale finite element mesh consisting of multiple elements encased in ~50–150μm sized grains with designated grain boundaries is used to replicate shapes and dimensions to simulate an isotropic metallic microstructure. The grains are encased in pseudo-grain boundary element sets which can have different material and damage parameters compared to the grains. In this type of mesh random crack paths for intergranular and transgranular cracking conditions are allowed. It is shown that creep cracking using a uniaxial ductility constraint-based model coupled with a functionally distributed time-dependent environmentally assisted corrosion/oxidation/material degradation damage model acting on surface or internally can be realistically predicted using this model. It is also evident material properties input data have scatter especially at the sub-grain level where the measurement methods are new and not always standardised. This is dealt with in the model by employing a normal distributive probabilistic method to allow for statistically varied random damage and crack growth development. In this way it is possible to take into account the inherent variability in material input properties at the analysis stage without the need to change material properties following each run. The method could negate the need for knowing the exact material properties, which in any case is impossible to derive at the microstructural level, as results of each run can be varied using a statistically distributed critical damage criterion specified for each element.

The aging degradation behavior of Fe-doped Lead zirconate titanate (PZT) subjected to different heat-treated temperatures was investigated over 1000h. The aging degradation in the piezoelectric properties of PZT was indicated by the decrease in piezoelectric charge coefficient, electric field-induced strain and remanent polarization. It was found that the aging degradation became more pronounced at temperature above 50% of the PZT’s Curie temperature. A mathematical model based on the linear logarithmic stretched exponential function was applied to explain the aging behavior. A qualitative aging model based on polar macrodomain switchability was proposed.

Developing Asia has grown faster than other parts of the world for decades. However, population aging is expected to pose significant headwinds to the region’s future economic growth. We update and enhance the analysis of Park and Shin (2012) to project the impact of population aging on developing Asia’s growth between 2021 and 2050. Our projections indicate that a demographic transition will have a substantial negative effect on the region’s future growth, but the effect varies across economies. Older economies will suffer a demographic tax, whereas younger economies will continue to enjoy a positive but declining demographic dividend.

Balance ability decreases with age, which results in an increased risk of falls for people over age 65. Tai Chi exercise appears to offer potential benefits in the reduction of falls for the elderly. The purpose of the present study was to examine the effects of extended (6- and 12-month) Tai Chi exercise interventions on balance and selected motor functions for senior citizens. Forty-seven subjects were recruited from two local senior centers. Twenty of them (M = 71.8 years, SD = 7.1), 11 in the Tai Chi exercise group and 9 in the control group, completed the pre-, mid- and post-tests over 12 months on five selected functional performance tests: static balance, dynamic balance, choice reaction time, heel-rise strength, and ankle flexibility. The Tai Chi group was provided with a one-hour Tai Chi exercise session per week for 12 months; the control group did not participate in any exercise program. Results showed that static balance improved significantly after a 6-month Tai Chi intervention. Moreover, the Tai Chi group maintained a higher level in the test performance compared with the control group at the end of the 12-month intervention, but there was no significant difference between the two groups. Data suggested that Tai Chi exercise intervention could produce a positive influence on balance control for the elderly over a prolonged period, but not on muscle strength and ankle flexibility.

Previous studies have suggested that Taiji practice may improve immune function. This study was intended to examine whether 5 months of moderate Taiji and Qigong (TQ) practice could improve the immune response to influenza vaccine in older adults. Fifty older adults (mean age 77.2 ± 1.3 years) participated in this study (TQ N = 27; wait-list control [CON] N = 23). Baseline pre-vaccine blood samples were collected. All subjects then received the 2003–2004 influenza vaccine during the first week of the intervention. Post-vaccine blood samples were collected 3, 6 and 20 weeks post-intervention for analysis of anti-influenza hemagglutination inhibition (HI) titers. We found a significant (p < 0.05) increase in the magnitude and duration of the antibody response to influenza vaccine in TQ participants when compared to CON. The vaccination resulted in a 173, 130, and 109% increase in HI titer at 3, 6, and 20 weeks post-vaccine, respectively, in the TQ group compared to 58, 54, and 10% in CON. There was a significant between group difference at 3 and 20 weeks post-vaccine and at 20 weeks the TQ group had significantly higher titers compared to the pre-vaccine time point, whereas the CON group did not. A higher percentage of TQ subjects also responded to the influenza A strains with a protective (> 40HI) antibody response (37% TQ vs. 20% CON for the H1N1 strain and 56% TQ vs. 45% CON for the H3N2 strain), but the differences between groups were not statistically significant. Traditional TQ practice improves the antibody response to influenza vaccine in older adults, but further study is needed to determine whether the enhanced response is sufficient to provide definitive protection from influenza infection.

With the acceleration of population aging in China, the number of pure beneficiaries in the economy is higher than that of pure contributors, which seriously affects fiscal sustainability. This paper probes into the influence path and mechanism of population aging to fiscal sustainability in China, and numerically simulates the extent of such influence using a generational accounting method. Aging reduces the tax base and enlarges fiscal expenditure by reducing the quantity of labor and labor productivity, changing the resident’s consumption level and structure, cutting down the saving rate, and widening the gap between social security revenue and expenditure, all of which challenge the balance of the fiscal system. The empirical results show that the problem of inequality in terms of the fiscal burden across generations is extremely prominent and the per capita tax burden under different birth rate assumptions is obviously different. Under the pressure of aging, in order to maintain the fiscal balance, the future per capita tax burden will be increased by a maximum of 55.9%. Although increasing productivity and reducing interest rates can help reduce that gap, their roles are far less important than the role of fertility. In order to cope with aging, the fiscal system should see an increase in income, a reduction in expenditure, and a redeployment of structure. That is, while at the same time perfecting the tax system and widening the tax base, the expenditure structure should also be optimized.

This study used reverse selection on populations of Drosophila melanogaster to test the evolutionary theory of aging, including antagonistic pleiotropy and mutation accumulation, the two non-exclusive population genetic mechanisms of aging. Specifically, reversed demographic selection was imposed on five populations selected for late-life fertility for 83 generations (O_1-5), returning them to an ancestral demographic schedule of 14 days. The five ancestral populations (B_1-5) were assayed each generation to serve as a control for environmental fluctuations over time. Relaxing selection for late-fecundity and imposing selection for early fecundity resulted in a rapid drop in longevity, and an increase in early fecundity, suggesting that longevity and some early life fitness component(s) are subject to antagonistic pleiotropy. As longevity fell, the frequency of the S allele of Pgm also decreased. Starvation resistance fell dramatically in reverse-selected males, and remained unchanged in females, suggesting that different physiological genetic mechanisms control resistance to starvation in the two sexes. Desiccation resistance remained unchanged under reverse demographic selection, implicating mutation accumulation as the primary mechanism for its evolution. Overall, these results provide some support for evolutionary theories of aging.

Typically, a selection response is lost when a selection regime is relaxed or terminated. Some possible explanations for this result are a negative genetic correlation between selected characters and fitness, antagonistic pleiotropy and linkage involving alleles of opposed effect, or a side-effect of relaxed inbreeding. The current study relaxes selection on stocks selected for resistance to starvation and desiccation stress, and the response to relaxed selection is then observed. Contrary to many findings, we found maintenance of the selection response with respect to some characters upon relaxation of the stress selection regime. Specifically, after 35 generations of relaxed selection, longevity, early fecundity, and desiccation resistance have not changed significantly in the relaxed desiccation-selection populations, suggesting that the alleles affecting these characters lack significant antagonistic pleiotropy. Starvation resistance, on the other hand, rose significantly in the relaxed desiccation populations. After 20 generations of relaxed selection, starvation resistance fell dramatically in the relaxed starvation-selection populations relative to their ancestral populations. Longevity, however, has not dropped significantly from that of its ancestral population. When early fecundity in the relaxed starvation-selection populations is analyzed separately at each generation, there is a significant increase in this character. This increase in early-life fecundity in association with the decrease in starvation resistance may reflect antagonistic pleiotropy between these two characters in the relaxed starvation resistance system.

Modern medicine has developed along a deductive pathway which advocates the identification of the cause of a disease entity, thence create a technique to clear the pathology. Chemical drugs are often involved in this process of target-shooting, which has been very successful when a disease has a single straightforward cause.

Aging involves complicated degenerative changes which cannot be corrected by simple removal or counteractions. Aging is affecting large populations and has become a public health problem. Developing multiple methodologies counteracting aging is an important issue for health providers. A new stream of clinicians has started special aging clinics in Europe and United States to give special services to the elderly who complain about fatigue, loss of energy and general malaise. This group assumes that those aging syndromes are the result of subtle hormonal deficiencies or subclinical toxic states. Basing on the “bullet-shot” theory, specific hormonal supplements or detoxications for the problems. The efficacy of this approach has to be proven. On the other hand, Oriental medicine advocates prevention of disease and degeneration before symptoms are felt. This can be done with active but non-strenuous exercise training, careful choice of a balanced diet and psychosocial means to maintain an internal harmony. To facilitate this practice of natural healing and disease prevention, practitioners of Chinese medicine have used a variety of herbs, either as accompanying ingredients in daily cooking or as specific broths. The Oriental way of natural healing demands a fervent personal commitment and is recommended for all those being challenged with aging.