Age patterns of incidence of geriatric disease in the U.S. elderly population: Medicare-based analysis

Genome-Related Mechanisms Contributing to Differences in Alzheimer's Disease Incidence Between White and Black Older US Adults

In this manuscript, we leverage a modified GWAS algorithm adapted for use with multidimensional Cox models and data from the Health and Retirement Study to explore how genetic variation influences the size of the disparity in Alzheimer's disease (AD) incidence between older Black and White US adults. We identified four loci that were associated with higher AD incidence levels in older Black adults: (1) rs11077034 (hazard ratio (HR), 4.98) from the RBFOX1 gene; (2) rs7144494 (HR, 1.68) from the HISLA gene; (3) rs7660552 (HR, 3.07) from the SLC25A4 gene; and (4) rs12599485 (HR, 3.181) from the NIP30 gene. The RBFOX1, HISLA, SLC25A4, and NIP30 genes are known to be associated with AD (RBFOX1, NIP30) directly, and also influence the risk of AD risk-related morbidities such as hypertension (RBFOX1, SLC25A4), depression (SLC25A4), and certain cancers (HISLA, SLC25A4). A likely disparity-generating mechanism may lie in endocytosis and abnormal tissue growing mechanisms, depending on inherited gene mutations and the structure of proxies as well as gene-environment interactions with other risk factors such as lifestyle, education level, and access to adequate medical services.

Understanding Alzheimer's disease in the context of aging: Findings from applications of stochastic process models to the Health and Retirement Study

There is growing literature on applications of biodemographic models, including stochastic process models (SPM), to studying regularities of age dynamics of biological variables in relation to aging and disease development. Alzheimer's disease (AD) is especially good candidate for SPM applications because age is a major risk factor for this heterogeneous complex trait. However, such applications are largely lacking. This paper starts filling this gap and applies SPM to data on onset of AD and longitudinal trajectories of body mass index (BMI) constructed from the Health and Retirement Study surveys and Medicare-linked data. We found that APOE e4 carriers are less robust to deviations of trajectories of BMI from the optimal levels compared to non-carriers. We also observed age-related decline in adaptive response (resilience) related to deviations of BMI from optimal levels as well as APOE- and age-dependence in other components related to variability of BMI around the mean allostatic values and accumulation of allostatic load. SPM applications thus allow revealing novel connections between age, genetic factors and longitudinal trajectories of risk factors in the context of AD and aging creating new opportunities for understanding AD development, forecasting trends in AD incidence and prevalence in populations, and studying disparities in those.

Forecasting prevalence and mortality of Alzheimer's disease using the partitioning models

OBJECTIVES

Health forecasting is an important aspect of ensuring that the health system can effectively respond to the changing epidemiological environment. Common models for forecasting Alzheimer's disease and related dementias (AD/ADRD) are based on simplifying methodological assumptions, applied to limited population subgroups, or do not allow analysis of medical interventions. This study uses 5 %-Medicare data (1991-2017) to identify, partition, and forecast age-adjusted prevalence and incidence-based mortality of AD as well as their causal components.

METHODS

The core underlying methodology is the partitioning analysis that calculates the relative impact each component has on the overall trend as well as intertemporal changes in the strength and direction of these impacts. B-spline functions estimated for all parameters of partitioning models represent the basis for projections of these parameters in future.

RESULTS

Prevalence of AD is predicted to be stable between 2017 and 2028 primarily due to a decline in the prevalence of pre-AD-diagnosis stroke. Mortality, on the other hand, is predicted to increase. In all cases the resulting patterns come from a trade-off of two disadvantageous processes: increased incidence and disimproved survival. Analysis of health interventions demonstrates that the projected burden of AD differs significantly and leads to alternative policy implications.

DISCUSSION

We developed a forecasting model of AD/ADRD risks that involves rigorous mathematical models and incorporation of the dynamics of important determinative risk factors for AD/ADRD risk. The applications of such models for analyses of interventions would allow for predicting future burden of AD/ADRD conditional on a specific treatment regime.

The Construction of a Multidomain Risk Model of Alzheimer's Disease and Related Dementias

BACKGROUND

Alzheimer's disease (AD) and related dementia (ADRD) risk is affected by multiple dependent risk factors; however, there is no consensus about their relative impact in the development of these disorders.

OBJECTIVE

To rank the effects of potentially dependent risk factors and identify an optimal parsimonious set of measures for predicting AD/ADRD risk from a larger pool of potentially correlated predictors.

METHODS

We used diagnosis record, survey, and genetic data from the Health and Retirement Study to assess the relative predictive strength of AD/ADRD risk factors spanning several domains: comorbidities, demographics/socioeconomics, health-related behavior, genetics, and environmental exposure. A modified stepwise-AIC-best-subset blanket algorithm was then used to select an optimal set of predictors.

RESULTS

The final predictive model was reduced to 10 features for AD and 19 for ADRD; concordance statistics were about 0.85 for one-year and 0.70 for ten-year follow-up. Depression, arterial hypertension, traumatic brain injury, cerebrovascular diseases, and the APOE4 proxy SNP rs769449 had the strongest individual associations with AD/ADRD risk. AD/ADRD risk-related co-morbidities provide predictive power on par with key genetic vulnerabilities.

CONCLUSION

Results confirm the consensus that circulatory diseases are the main comorbidities associated with AD/ADRD risk and show that clinical diagnosis records outperform comparable self-reported measures in predicting AD/ADRD risk. Model construction algorithms combined with modern data allows researchers to conserve power (especially in the study of disparities where disadvantaged groups are often grossly underrepresented) while accounting for a high proportion of AD/ADRD-risk-related population heterogeneity stemming from multiple domains.

Why twin studies are important for health span science research: the case of maltreatment of aging adults

Average life expectancies have lengthened across human history. As a result, there is an increased need to care for a greater number of individuals experiencing common age-related declines in health. This has helped to spur a rapidly increasing focus on understanding "health span", the portion of the life-course spent functionally healthy. Yet to penetrate the science of health span, however, is a topic which seems fundamental to the ability to age in functional and healthy ways, and has received considerable attention in other fields. As more of the population ages, the risk of exposure to abuse and neglect among older citizens not only rises, but can manifest as both cause and effect of declining health span. Among our goals here is to make a case for including this subject among the other central components of health span science. In so doing, we also outline reasons why quantitative genetic designs using samples of twins can be a versatile tool for improving causal inference when studying maltreatment among older persons specifically, but also on a range of other health span topics in general.

What Is an Aging-Related Disease? An Epidemiological Perspective

There are no established or standardized definitions of aging-related disease. Data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 were used to model the relationship between age and incidence of diseases. Clustering analysis identified 4 groups of noncommunicable diseases: Group A diseases with an exponential increase in incidence with age; Group B diseases with an exponential increase in incidence that usually peaked in late life which then declined or plateaued at the oldest ages; and Groups C and D diseases with an onset in earlier life and where incidence was stable or decreased in old age. From an epidemiological perspective, Group A diseases are "aging-related diseases" because there is an exponential association between age and incidence, and the slope of the incidence curves remains positive throughout old age. These included the major noncommunicable diseases dementia, stroke, and ischemic heart disease. Whether any of the other diseases are aging-related is uncertain because their incidence either does not change or more often decreases in old age. Only biological studies can determine how the aging process contributes to any of these diseases and this may lead to a reclassification of disease on the basis of whether they are directly caused by or are in continuity with the biological changes of aging. In the absence of this mechanistic data, we propose the term "aging-related disease" should be used with precision based on epidemiological evidence.

Vulnerability to Hypertension Is a Major Determinant of Racial Disparities in Alzheimer's Disease Risk

BACKGROUND

Higher incidence levels of Alzheimer's disease (AD) in Black Americans are well documented. However, quantitative explanations of this disparity in terms of risk-factor diseases acting through well-defined pathways are lacking.

METHODS

We applied a Blinder-Oaxaca-based algorithm modified for censored data to a 5% random sample of Medicare beneficiaries age 65+ to explain Black/White disparities in AD risk in terms of differences in exposure and vulnerability to morbidity profiles based on 10 major AD-risk-related diseases.

RESULTS

The primary contribution to racial disparities in AD risk comes from morbidity profiles that included hypertension with about 1/5th of their contribution due to differences in prevalence (exposure effect) and 4/5ths to differences in the effects of the morbidity profile on AD risk (vulnerability effect). In total, disease-related effects explained a higher proportion of AD incidence in Black Americans than in their White counterparts.

CONCLUSIONS

Disease-related causes may represent some of the most straightforward targets for targeted interventions aimed at the reduction of racial disparities in health among US older adults. Hypertension is a manageable and potentially preventable condition responsible for the majority of the Black/White differences in AD risk, making mitigation of the role of this disease in engendering higher AD incidence in Black Americans a prominent concern.

Extended anesthesia exposure for abdominal and pelvic procedures in older adults with colorectal cancer: Associations with chart dementia diagnoses

BACKGROUND

We hypothesized that cumulative anesthesia exposure over the course of routine treatment of colorectal cancer in older adults can increase long-term risk of Alzheimer's disease (AD), Alzheimer's disease-related dementias (ADRD), and other chronic neurocognitive disorders (CND).

METHODS

We conducted a SEER-Medicare-based retrospective cohort study of 84,770 individuals age 65 years and older diagnosed with colorectal cancer between 1998 and 2007 using a proportional hazards model with inverse probability weighted estimators. The primary exploratory variable was a time-variant measure of cumulative anesthesia exposure for abdominal and pelvic procedures, updated continuously.

RESULTS

Our primary outcomes, AD and ADRD, occurred in 6005/84,770 (7.1%) and 14,414/83,444 (17.3%) individuals respectively. No statistically significant association was found between cumulative anesthesia exposure and AD (hazard ratio [HR], 0.993; 95% CI, 0.973-1.013). However, it was moderately associated with the risk of ADRD (HR, 1.016; 95% CI, 1.004-1.029) and some secondary outcomes including most notably: cerebral degeneration (HR, 1.048; 95% CI, 1.033-1.063), hepatic encephalopathy (HR, 1.133; 95% CI, 1.101-1.167), encephalopathy-not elsewhere classified (HR,1.095; 95% CI: 1.076-1.115), and incident/perioperative delirium (HR, 1.022; 95% CI, 1.012-1.032). Furthermore, we observed an association between perioperative delirium and increased risk of AD (HR, 2.05; 95% CI, 1.92-2.09).

CONCLUSION

Cumulative anesthesia exposure for abdominal and pelvic procedures was not associated with increased risk of AD directly and had a small but statistically significant association with ADRD and a number of other CNDs. Cumulative anesthesia exposure was also associated with perioperative delirium, which had an independent adverse association with AD risk.

Subclinical cardiovascular disease and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) impacts approximately 6%-10% of women worldwide, with hallmark features of hyperandrogenism, irregular menses, infertility, and polycystic appearing ovaries on ultrasound. In addition, PCOS is associated with several endocrine and metabolic disorders, including obesity, insulin resistance and diabetes mellitus, hypertension, dyslipidemia and metabolic syndrome, which all increase the risk for subclinical cardiovascular disease (CVD), the presence of altered vascular endothelium without overt CVD. In this review, we summarize the most recent literature regarding subclinical CVD in women with PCOS, including markers such as flow-mediated dilation, arterial stiffness, coronary artery calcium scores, carotid intima-media thickness and visceral and epicardial fat.

Landfall After the Perfect Storm: Cohort Differences in the Relationship Between Debt and Risk of Heart Attack

Analyses of the Health and Retirement Study (HRS) between 1992 and 2014 compare the relationship between different levels and forms of debt and heart attack risk trajectories across four cohorts. Although all cohorts experienced growing household debt, including the increase of both secured and unsecured debt, they nevertheless encountered different economic opportunity structures and crises at sensitive times in their life courses, with implications for heart attack risk trajectories. Results from frailty hazards models reveal that unsecured debt is associated with increased risk of heart attack across all cohorts. Higher levels of housing debt, however, predict higher rates of heart attack among only the earlier cohorts. Heart attack risk trajectories for Baby Boomers with high levels of housing debt are lower than those of same-aged peers with no housing debt. Thus, the relationship between debt and heart attack varies by level and form of debt across cohorts but distinguishes Baby Boomer cohorts based on their diverse exposures to volatile housing market conditions over the sensitive household formation period of the life course.

Interactions Between Genes From Aging Pathways May Influence Human Lifespan and Improve Animal to Human Translation

A major goal of aging research is identifying genetic targets that could be used to slow or reverse aging - changes in the body and extend limits of human lifespan. However, majority of genes that showed the anti-aging and pro-survival effects in animal models were not replicated in humans, with few exceptions. Potential reasons for this lack of translation include a highly conditional character of genetic influence on lifespan, and its heterogeneity, meaning that better survival may be result of not only activity of individual genes, but also gene-environment and gene-gene interactions, among other factors. In this paper, we explored associations of genetic interactions with human lifespan. We selected candidate genes from well-known aging pathways (IGF1/FOXO growth signaling, P53/P16 apoptosis/senescence, and mTOR/SK6 autophagy and survival) that jointly decide on outcomes of cell responses to stress and damage, and so could be prone to interactions. We estimated associations of pairwise statistical epistasis between SNPs in these genes with survival to age 85+ in the Atherosclerosis Risk in Communities study, and found significant (FDR < 0.05) effects of interactions between SNPs in IGF1R, TGFBR2, and BCL2 on survival 85+. We validated these findings in the Cardiovascular Health Study sample, with P < 0.05, using survival to age 85+, and to the 90th percentile, as outcomes. Our results show that interactions between SNPs in genes from the aging pathways influence survival more significantly than individual SNPs in the same genes, which may contribute to heterogeneity of lifespan, and to lack of animal to human translation in aging research.

Analysis of Time Trends in Alzheimer's Disease and Related Dementias Using Partitioning Approach

BACKGROUND

Understanding the dynamics of epidemiologic trends in Alzheimer's disease (AD) and related dementias (ADRD) and their epidemiologic causes is vital to providing important insights into reducing the burden associated with these conditions.

OBJECTIVE

To model the time trends in age-adjusted AD/ADRD prevalence and incidence-based mortality (IBM), and identify the main causes of the changes in these measures over time in terms of interpretable epidemiologic quantities.

METHODS

Trend decomposition was applied to a 5%sample of Medicare beneficiaries between 1991 and 2017.

RESULTS

Prevalence of AD was increasing between 1992 and 2011 and declining thereafter, while IBM increased over the study period with a significant slowdown in its rate of growth from 2011 onwards. For ADRD, prevalence and IBM increased through 2014 prior to taking a downwards turn. The primary determinant responsible for declines in prevalence and IBM was the deceleration in the increase and eventual decrease in incidence rates though changes in relative survival began to affect the overall trends in prevalence/IBM in a noticeable manner after 2008. Other components showed only minor effects.

CONCLUSION

The prevalence and IBM of ADRD is expected to continue to decrease. The directions of these trends for AD are not clear because AD incidence, the main contributing component, is decreasing but at a decreasing rate suggesting a possible reversal. Furthermore, emerging treatments may contribute through their effects on survival. Improving ascertainment of AD played an important role in trends of AD/ADRD over the 1991-2009/10 period but this effect has exhausted itself by 2017.

Dyslipidemia and prevention of atherosclerotic cardiovascular disease in the elderly

The atherosclerotic cardiovascular disease (ASCVD) represents the leading cause of death and disability in the elderly. The study of atherosclerosis and the strategies to control ASCVD are evolving. All strategies emphasize the need to lower LDL cholesterol (LDL-C) through an appropriate lifestyle and the use of lipid-lowering drugs, mainly statins. Available evidence coming from clinical trials is useful to inform clinical choices but the older people are poorly represented in those trials. Thus evidence supporting the benefit of statin therapy for primary and secondary prevention of fatal and nonfatal ASCVD events in adults aged 75 years and older are limited. The pharmacological therapy of dyslipidemia is recommended by guidelines provided by international expert panels in adults, while in the elderly it is still a matter of debate. Statins are generally well tolerated drugs but their use in the elderly, especially in fragile ones or with multi-pathology that take many other drugs, requires a careful evaluation of the risk-benefit ratio and a shared decision-making process between doctor and patient.

Chemotherapy and the Risk of Alzheimer's Disease in Colorectal Cancer Survivors: Evidence From the Medicare System

PURPOSE

Evidence on the nature of the relationship between patients receiving chemotherapy as an essential part of guideline-concordant cancer care and the onset of Alzheimer's Disease (AD) and other adverse cognitive outcomes has been mixed. Biological mechanisms were proposed to support both a potentially beneficial and an adverse role. To explore the relationship between chemotherapy and onset of AD and other neurocognitive disorders (ND) in colorectal cancer survivors.

METHODS

We conducted a retrospective cohort study of 135,834 individuals older than 65 years diagnosed with colorectal cancer between 1998 and 2007, using SEER-Medicare data. A proportional hazards model was used before and after the use of inverse probability weighting to account for populational differences between the chemotherapy and nonchemotherapy groups. Weights were normalized to the total sample size.

RESULTS

After inverse probability weighting, chemotherapy was associated with decreased AD risk (hazard ratio [HR]: 0.791; 95% CI: 0.758 to 0.824) and lower risk for the majority of other ND including AD-related diseases (HR: 0.823; CI: 0.802 to 0.844), dementia (permanent mental disorder) (HR: 0.807; CI: 0.782 to 0.832), and dementia (senile) (HR: 0.772; CI: 0.745 to 0.801). The only adverse effect to remain significant was cerebral degeneration (excluding AD) (HR: 1.067; CI: 1.033 to 1.102). The effects for AD remained after treatment was stratified by chemotherapy agent type and remained significant for up to 6 years past diagnosis.

CONCLUSION

Chemotherapy use in colorectal cancer survivors demonstrated an association with reduced risk for AD and other ND.

Data-driven identification of ageing-related diseases from electronic health records

Reducing the burden of late-life morbidity requires an understanding of the mechanisms of ageing-related diseases (ARDs), defined as diseases that accumulate with increasing age. This has been hampered by the lack of formal criteria to identify ARDs. Here, we present a framework to identify ARDs using two complementary methods consisting of unsupervised machine learning and actuarial techniques, which we applied to electronic health records (EHRs) from 3,009,048 individuals in England using primary care data from the Clinical Practice Research Datalink (CPRD) linked to the Hospital Episode Statistics admitted patient care dataset between 1 April 2010 and 31 March 2015 (mean age 49.7 years (s.d. 18.6), 51% female, 70% white ethnicity). We grouped 278 high-burden diseases into nine main clusters according to their patterns of disease onset, using a hierarchical agglomerative clustering algorithm. Four of these clusters, encompassing 207 diseases spanning diverse organ systems and clinical specialties, had rates of disease onset that clearly increased with chronological age. However, the ages of onset for these four clusters were strikingly different, with median age of onset 82 years (IQR 82–83) for Cluster 1, 77 years (IQR 75–77) for Cluster 2, 69 years (IQR 66–71) for Cluster 3 and 57 years (IQR 54–59) for Cluster 4. Fitting to ageing-related actuarial models confirmed that the vast majority of these 207 diseases had a high probability of being ageing-related. Cardiovascular diseases and cancers were highly represented, while benign neoplastic, skin and psychiatric conditions were largely absent from the four ageing-related clusters. Our framework identifies and clusters ARDs and can form the basis for fundamental and translational research into ageing pathways.

Roles of interacting stress-related genes in lifespan regulation: insights for translating experimental findings to humans

AIM

Experimental studies provided numerous evidence that caloric/dietary restriction may improve health and increase the lifespan of laboratory animals, and that the interplay among molecules that sense cellular stress signals and those regulating cell survival can play a crucial role in cell response to nutritional stressors. However, it is unclear whether the interplay among corresponding genes also plays a role in human health and lifespan.

METHODS

Literature about roles of cellular stressors have been reviewed, such as amino acid deprivation, and the integrated stress response (ISR) pathway in health and aging. Single nucleotide polymorphisms (SNPs) in two candidate genes (GCN2/EIF2AK4 and CHOP/DDIT3) that are closely involved in the cellular stress response to amino acid starvation, have been selected using information from experimental studies. Associations of these SNPs and their interactions with human survival in the Health and Retirement Study data have been estimated. The impact of collective associations of multiple interacting SNP pairs on survival has been evaluated, using a recently developed composite index: the SNP-specific Interaction Polygenic Risk Score (SIPRS).

RESULTS

Significant interactions have been found between SNPs from GCN2/EIF2AK4 and CHOP/DDI3T genes that were associated with survival 85+ compared to survival between ages 75 and 85 in the total sample (males and females combined) and in females only. This may reflect sex differences in genetic regulation of the human lifespan. Highly statistically significant associations of SIPRS [constructed for the rs16970024 (GCN2/EIF2AK4) and rs697221 (CHOP/DDIT3)] with survival in both sexes also been found in this study.

CONCLUSION

Identifying associations of the genetic interactions with human survival is an important step in translating the knowledge from experimental to human aging research. Significant associations of multiple SNPxSNP interactions in ISR genes with survival to the oldest old age that have been found in this study, can help uncover mechanisms of multifactorial regulation of human lifespan and its heterogeneity.

Decline in biological resilience as key manifestation of aging: Potential mechanisms and role in health and longevity

Decline in biological resilience (ability to recover) is a key manifestation of aging that contributes to increase in vulnerability to death with age eventually limiting longevity even in people without major chronic diseases. Understanding the mechanisms of this decline is essential for developing efficient anti-aging and pro-longevity interventions. In this paper we discuss: a) mechanisms of the decline in resilience with age, and aging components that contribute to this decline, including depletion of body reserves, imperfect repair mechanisms, and slowdown of physiological processes and responses with age; b) anti-aging interventions that may improve resilience or attenuate its decline; c) biomarkers of resilience available in human and experimental studies; and d) genetic factors that could influence resilience. There are open questions about optimal anti-aging interventions that would oppose the decline in resilience along with extending longevity limits. However, the area develops quickly, and prospects are exciting.

Physical robustness and resilience among long-lived female siblings: a comparison with sporadic long-livers

Long-lived individuals are central in studies of healthy longevity. However, few pro-longevity factors have been identified, presumably because of “phenocopies”, i.e. individuals that live long by chance. Familial longevity cases may include less phenocopies than sporadic cases and provide better insights into longevity mechanisms. Here we examined whether long-lived female siblings have a better ability to avoid diseases at ages 65+ (proxy for “robustness”) and/or survive to extreme ages (proxy for “resilience”) compared to sporadic long-livers. A total of 1,156 long-lived female siblings were selected from three nationwide Danish studies and age-matched with sporadic long-lived female controls. Outcomes included cumulative incidence of common health disorders from age 65 and overall survival. Long-lived female siblings had lower risks of some but not all health conditions, most significantly, depression (OR=0.74; 95%CI=0.62-0.88), and less significantly hypertensive (OR=0.84; 95%CI=0.71-0.99) and cerebrovascular (OR=0.73; 95%CI=0.55-0.96) diseases. They also had consistently better survival to extreme ages (HR=0.71; 95%CI= 0.63-0.81) compared to sporadic long-livers. After adjustment for the diseases, the association with mortality changed only marginally suggesting central role of better physiological resilience in familial longevity. Due to their consistently better resilience, familial longevity cases could be more informative than sporadic cases for studying mechanisms of healthy longevity.

Independent associations of TOMM40 and APOE variants with body mass index

The TOMM40-APOE variants are known for their strong, antagonistic associations with Alzheimer's disease and body weight. While a stronger role of the APOE than TOMM40 variants in Alzheimer's disease was suggested, comparative contribution of the TOMM40-APOE variants in the regulation of body weight remains elusive. We examined additive effects of rs2075650 and rs157580 TOMM40 variants and rs429358 and rs7412 APOE variants coding the ε2/ε3/ε4 polymorphism on body mass index (BMI) in age-aggregated and age-stratified cohort-specific and cohort-pooled analysis of 27,863 Caucasians aged 20-100 years from seven longitudinal studies. Minor alleles of rs2075650, rs429358, and rs7412 were individually associated with BMI (β = -1.29, p = 3.97 × 10^-9 ; β = -1.38, p = 2.78 × 10^-10 ; and β = 0.58, p = 3.04 × 10^-2 , respectively). Conditional analysis with rs2075650 and rs429358 identified independent BMI-lowering associations for minor alleles (β = -0.63, p = 3.99 × 10^-2 and β = -0.94, p = 2.17 × 10^-3 , respectively). Polygenic mega-analysis identified additive effects of the rs2075650 and rs429358 heterozygotes (β = -1.68, p = 3.00 × 10^-9 ), and the strongest BMI-lowering association for the rs2075650 heterozygous and rs429358 minor allele homozygous carriers (β = -4.11, p = 2.78 × 10^-3 ). Conditional analysis with four polymorphisms identified independent BMI-lowering (rs2075650, rs157580, and rs429358) and BMI-increasing (rs7412) associations of heterozygous genotypes with BMI. Age-stratified conditional analysis revealed well-powered support for a differential and independent association of the rs429358 heterozygote with BMI in younger and older individuals, β = 0.58, 95% confidence interval (CI) = -1.18, 2.35, p = 5.18 × 10^-1 for 3,068 individuals aged ≤30 years and β = -4.28, CI = -5.65, -2.92, p = 7.71 × 10^-10 for 6,052 individuals aged >80 years. TOMM40 and APOE variants are independently and additively associated with BMI. The APOE ε4-coding rs429358 polymorphism is associated with BMI in older individuals but not in younger individuals.

Lower Prescription Rates in Centenarians with Heart Failure and Heart Failure and Kidney Disease Combined: Findings from a Longitudinal Cohort Study of Very Old Patients

BACKGROUND

Centenarians are considered as models of successful aging and represent a special group of patients. The aim of this study was to analyze heart failure epidemiology and treatment trajectories in centenarians compared to nonagenarians (90-99 years of age) and octogenarians (80-89 years of age) with heart failure and with heart failure and kidney disease combined.

METHODS

This cohort study used quarterly structured routine data from 1398 German insurants over 6 years prior to death (398 centenarians were compared with 500 nonagenarians and 500 octogenarians). Of those, 525 individuals were diagnosed with heart failure before death; 164 had heart failure and kidney disease combined. Generalized estimation equations were used to assess the association of diagnoses of heart failure and other diseases with medication prescriptions.

RESULTS

Across age groups, heart failure was significantly more prevalent in centenarians compared with octogenarians and nonagenarians. Prevalence of heart failure increased over time. Female sex [odds ratio (men) = 0.70, p = 0.024], kidney disease (odds ratio = 1.31, p < 0.001), and hypertension (odds ratio = 1.52, p < 0.001) were all associated with heart failure. Overall, heart failure treatment changed significantly over time with an increased prescription rate of loop diuretics and a decreased rate of renin-angiotensin-system inhibitors. Centenarians were significantly less likely to receive treatment with renin-angiotensin-system inhibitors, loop diuretics, or beta-blockers compared with nonagenarians and octogenarians. Furthermore, aldosterone inhibitors were seldom prescribed; If-channel and neprilysin inhibitors were not routinely used in our sample. For those with heart failure and kidney disease combined, our data revealed that the prevalence of kidney disease was lower in centenarians than in younger patients before death. However, differences in prescription rates across age groups were non-significant, although numerically large. Finally, half of the patients in all three age groups with heart failure and kidney disease received treatment with renin-angiotensin-system inhibitors; about two out of five patients received beta-blockers, while prescription rates of aldosterone inhibitors were low.

CONCLUSIONS

While heart failure prevalence shows a continuous increase with age, prescription rates are lower in centenarians, emphasizing the need for further studies considering the quality of care and outcomes in this patient population. Disease management programs and trials are needed to develop guidelines that address the medically challenging treatment for very old patients with comorbid heart failure and kidney disease.

Statins for Primary Prevention in Older Adults-Moving Toward Evidence-Based Decision-Making

OBJECTIVES

To determine the efficacy and safety of statins for primary prevention of atherosclerotic cardiovascular disease (ASCVD) events in older adults, especially those aged 80 and older and with multimorbidity.

METHODS

The National Institute on Aging and the National Heart, Lung and Blood Institute convened A multidisciplinary expert panel from July 31 to August 1, 2017, to review existing evidence, identify knowledge gaps, and consider whether statin safety and efficacy data in persons aged 75 and older without ASCVD are sufficient; whether existing data can inform the feasibility, design, and implementation of future statin trials in older adults; and clinical trial options and designs to address knowledge gaps. This article summarizes the presentations and discussions at that workshop.

RESULTS

There is insufficient evidence regarding the benefits and harms of statins in older adults, especially those with concomitant frailty, polypharmacy, comorbidities, and cognitive impairment; a lack of tools to assess ASCVD risk in those aged 80 and older; and a paucity of evidence of the effect of statins on outcomes of importance to older adults, such as statin-associated muscle symptoms, cognitive function, and incident diabetes mellitus. Prospective, traditional, placebo-controlled, randomized clinical trials (RCTs) and pragmatic RCTs seem to be suitable options to address these critical knowledge gaps. Future trials have to consider greater representation of very old adults, women, underrepresented minorities, and individuals of differing health, cognitive, socioeconomic, and educational backgrounds. Feasibility analyses from existing large healthcare networks confirm appropriate power for death and cardiovascular outcomes for future RCTs in this area.

CONCLUSION

Existing data cannot address uncertainties about the benefits and harms of statins for primary ASCVD prevention in adults aged 75 and older, especially those with comorbidities, frailty, and cognitive impairment. Evidence from 1 or more RCTs could address these important knowledge gaps to inform person-centered decision-making. J Am Geriatr Soc 66:2188-2196, 2018.

Atrial fibrillation and medication treatment among centenarians: Are all very old patients treated the same?

AIM

Evidence on antithrombotic therapy use in centenarians diagnosed with atrial fibrillation (AF) is sparse. Our objective was to investigate a possible underprescribing in centenarians relative to younger cohorts of the oldest-old. We assumed lower AF rates; and, within AF patients, lower use of anticoagulants in those who died as centenarians (aged ≥100 years) than in those who died aged in their 80s (≥80 years) or 90s (≥90 years).

METHODS

The present study was a quarterly structured cohort study over the 6 years before death using administrative data from German institutionalized and non-institutionalized insured patients (whole sample n = 1398 and subsample of AF patients n = 401 subclassified according to age-of-death groups [≥80, ≥90, ≥100 years]). AF, medication, stroke risk (Congestive heart failure; Hypertension; 2 × Age ≥75 years; Diabetes mellitus; 2 × Stroke; Vascular disease; Age 65-74 years; Sex [female] (CHA₂ DS₂ -VASc)) and risk of major bleeding (Hypertension; Abnormal renal and liver function; Stroke; Bleeding; Labile International Normalized Ratio [omitted in the present analysis]; Elderly; Drugs or alcohol (HAS-BLED)) were calculated. Generalized estimation equations were used to model the trajectories.

RESULTS

Half a year before death (T1), AF rates were higher in patients aged ≥80 years (31.8%) and ≥90 years (30.6%) compared with patients aged ≥100 years (22.4%), whereas there were no significant differences between age groups 6 years before death (T0). Of all AF patients with AF at T1, 26.7% received anticoagulants; 11.2% vitamin K antagonists; 15.7% non-vitamin K antagonist oral anticoagulants; and 17.5% platelet inhibitors; yet 58.1% received none of these drugs. Centenarians received significantly fewer anticoagulants compared with the other age groups. Prescriptions of anticoagulants were not associated with CHA₂ DS₂ -VASc with and without adjustment for HAS-BLED.

CONCLUSIONS

The present findings highlight the need for more appropriate use of anticoagulation therapy in older patients, as well as for new treatment guidelines taking the heterogeneity of very old patients into account. Geriatr Gerontol Int 2018; 18: 1634-1640.

Identifying the causes of the changes in the prevalence patterns of diabetes in older U.S. adults: A new trend partitioning approach

AIMS

To identify how efforts to control the diabetes epidemic and the resulting changes in diabetes mellitus, type II (T2D) incidence and survival have affected the time-trend of T2D prevalence.

METHODS

A newly developed method of trend decomposition was applied to a 5% sample of Medicare administrative claims filed between 1991 and 2012.

RESULTS

Age-adjusted prevalence of T2D for adults age 65+ increased at an average annual percentage change of 2.31% between 1992 and 2012. Primary contributors to this trend were (in order of magnitude): improved survival at all ages, increased prevalence of T2D prior to age of Medicare eligibility, decreased incidence of T2D after age of Medicare eligibility.

CONCLUSIONS

Health services supported by the Medicare system, coupled with improvements in medical technology and T2D awareness efforts provide effective care for individuals age 65 and older. However, policy maker attention should be shifted to the prevention of T2D in younger age groups to control the increase in prevalence observed prior to Medicare eligibility.

Completion of the Circle of Willis Varies by Gender, Age, and Indication for Computed Tomography Angiography

OBJECTIVE

The circle of Willis (CoW) is the foremost anastomosis and blood distribution center of the brain. Its effectiveness depends on its completion and the size and patency of its vessels. Gender-related and age-related anatomic variations in the CoW may play an important role in the pathogenesis of cerebrovascular diseases. In this study, we analyzed computed tomography angiograms (CTAs) to assess for differences in CoW completion related to gender, age, and indication for CTA.

METHODS

A total of 834 CTAs were retrospectively analyzed for all CoW vessels to compare the incidence of complete CoW and variation frequency based on gender, age, and indication.

RESULTS

The incidence of complete CoW was 37.1% overall. CoW completion showed a statistically significant decrease with increasing age for all age groups in both men (47.0%, 29.4%, 18.8%) and women (59.1%, 44.2%, 30.9%). Completion was greater in women (43.8%) than in men (31.2%) overall and for all age groups. These gender differences were all statistically significant except for the 18-39 years age group. The most frequent of the 28 CoW variations were absent posterior communicating artery (PCOM) bilaterally (17.1%), right PCOM (15.3%), and left PCOM (10.9%). Ischemic stroke and the 18-39 years age group of hemorrhagic stroke showed a statistically significant reduction in completion relative to trauma.

CONCLUSIONS

The incidence of complete CoW is likely greater in women for all age groups and likely decreases with age in both genders. The most frequently absent vessel is likely the PCOM, either unilaterally or bilaterally. Completion may play a role in ischemic stroke and a subset of patients with hemorrhagic stroke.

Parkinson's in the oldest old: Impact on estimates of future disease burden

BACKGROUND

Traditionally the risk of Parkinson's has been considered to increase monotonically with age, although there is evidence that prevalence and incidence may decrease in the oldest old. To examine this further we estimated the national prevalence and incidence of Parkinson's in New Zealand, using drug-tracing methods, to examine the relationship of Parkinson's with sex and age up to 100+.

METHODS

Information on Parkinson's-related medications was extracted from the national pharmaceutical database of community-dispensed medications from 2005 to 2014. Diagnoses for a large subset of individuals were independently determined through national mortality and hospital admissions datasets. We used a Bayesian model, accommodating diagnostic uncertainty and bias, to estimate the number of people with Parkinson's.

RESULTS

The 2013 prevalence of Parkinson's in New Zealand was 210 per 100 000 population (95% uncertainty interval 208-212) with age-standardized prevalence rates higher for males (ratio 1.6:1). Incidence was 31 per 100 000 person-years (95% uncertainty interval 30-32), also higher in males (ratio 1.8:1). Incidence and prevalence by age increased exponentially until 75 years, peaked at 85 years, and then dropped sharply.

CONCLUSIONS

The prevalence of Parkinson's in New Zealand is expected to double over a 25-year period but then increase at a slower rate due to the drop-off in prevalence and incidence in the oldest old. The findings suggest that Parkinson's disease is not an aging-dependent but an age-dependent disorder.

Misclassification of incident hospitalized and outpatient heart failure in administrative claims data: the Atherosclerosis Risk in Communities (ARIC) study

PURPOSE

The aim of this study was to quantify the influence of the length of the look-back period on misclassification of heart failure (HF) incidence in Medicare claims available for participants of a population-based cohort.

METHODS

Atherosclerosis Risk in Communities participants with ≥3 years of continuous fee-for-service Medicare enrollment from 2000 to 2012 was assigned an index date 36 months after enrollment separating the time-in-observation period into the look-back and the incidence periods. Incident HF events were identified using ICD-9-CM code algorithms as the first observed hospitalization claim or the second of two HF outpatient claims occurring within 12 months. Using 36 months as a referent, the look-back period was reduced by 6-month increments. For each look-back period, we calculated the incidence rate, percent of prevalent HF events misclassified as incident, and loss in sample size.

RESULTS

We identified 9568 Atherosclerosis Risk in Communities participants at risk for HF. For hospitalized and outpatient HF, the number of events misclassified as incident increased, and the total number of incident events decreased with increased length of the look-back period. The incident rate (per 1000 person years) decreased with increased length of the look-back period from 6 to 36 months and had a greater impact on outpatient HF; for example, from 11.2 to 10.6 for ICD-9-CM 428.xx hospitalization in the primary position and 10.5 to 7.9 for outpatient HF.

CONCLUSION

Our estimates can be used to optimize trade-offs between the degree of misclassification and number of events in the estimation of incident HF from administrative claims data, as pertinent to different study questions. Copyright © 2017 John Wiley & Sons, Ltd.

Theory of partitioning of disease prevalence and mortality in observational data

In this study, we present a new theory of partitioning of disease prevalence and incidence-based mortality and demonstrate how this theory practically works for analyses of Medicare data. In the theory, the prevalence of a disease and incidence-based mortality are modeled in terms of disease incidence and survival after diagnosis supplemented by information on disease prevalence at the initial age and year available in a dataset. Partitioning of the trends of prevalence and mortality is calculated with minimal assumptions. The resulting expressions for the components of the trends are given by continuous functions of data. The estimator is consistent and stable. The developed methodology is applied for data on type 2 diabetes using individual records from a nationally representative 5% sample of Medicare beneficiaries age 65+. Numerical estimates show excellent concordance between empirical estimates and theoretical predictions. Evaluated partitioning model showed that both prevalence and mortality increase with time. The primary driving factors of the observed prevalence increase are improved survival and increased prevalence at age 65. The increase in diabetes-related mortality is driven by increased prevalence and unobserved trends in time-periods and age-groups outside of the range of the data used in the study. Finally, the properties of the new estimator, possible statistical and systematical uncertainties, and future practical applications of this methodology in epidemiology, demography, public health and health forecasting are discussed.

Trade-offs in the effects of the apolipoprotein E polymorphism on risks of diseases of the heart, cancer, and neurodegenerative disorders: insights on mechanisms from the Long Life Family Study

The lack of evolutionary established mechanisms linking genes to age-related traits makes the problem of genetic susceptibility to health span inherently complex. One complicating factor is genetic trade-off. Here we focused on long-living participants of the Long Life Family Study (LLFS), their offspring, and spouses to: (1) Elucidate whether trade-offs in the effect of the apolipoprotein E e4 allele documented in the Framingham Heart Study (FHS) are a more general phenomenon, and (2) explore potential mechanisms generating age- and gender-specific trade-offs in the effect of the e4 allele on cancer, diseases of the heart, and neurodegenerative disorders assessed retrospectively in the LLFS populations. The e4 allele can diminish risks of cancer and diseases of the heart and confer risks of diseases of the heart in a sex-, age-, and LLFS-population-specific manner. A protective effect against cancer is seen in older long-living men and, potentially, their sons (>75 years, relative risk [RR]>75=0.48, p=0.086), which resembles our findings in the FHS. The protective effect against diseases of the heart is limited to long-living older men (RR>76=0.50, p=0.016), as well. A detrimental effect against diseases of the heart is characteristic for a normal LLFS population of male spouses and is specific for myocardial infarction (RR=3.07, p=2.1×10(-3)). These trade-offs are likely associated with two inherently different mechanisms, including disease-specific (detrimental; characteristic for a normal male population) and systemic, aging-related (protective; characteristic for older long-living men) mechanisms. The e4 allele confers risks of neurological disorders in men and women (RR=1.98, p=0.046). The results highlight the complex role of the e4 allele in genetic susceptibility to health span.

Achieving consensus and controversy around applicability of palliative care to dementia

BACKGROUND

People with dementia may benefit from palliative care which specifically addresses the needs of patients and families affected by this life-limiting disease. On behalf of the European Association for Palliative Care (EAPC), we recently performed a Delphi study to define domains for palliative care in dementia and to provide recommendations for optimal care. An international panel of experts in palliative care, dementia care or both, achieved consensus on almost all domains and recommendations, but the domain concerning the applicability of palliative care to dementia required revision.

METHODS

To examine in detail, the opinions of the international panel of 64 experts around the applicability of palliative care, we explored feedback they provided in the Delphi process. To examine which experts found it less important or less applicable, ordinal regression analyses related characteristics of the panelists to ratings of overall importance of the applicability domain, and to agreement with the domain's four recommendations.

RESULTS

Some experts expressed concerns about bringing up end-of-life issues prematurely and about relabeling dementia care as palliative care. Multivariable analyses with the two outcomes of importance and agreement with applicability indicated that younger or less experienced experts and those whose expertise was predominantly in dementia care found palliative care in dementia less important and less applicable.

CONCLUSIONS

Benefits of palliative care in dementia are acknowledged by experts worldwide, but there is some controversy around its early introduction. Further studies should weigh concerns expressed around care receiving a "palliative" label versus the benefits of applying palliative care early.

Puzzling role of genetic risk factors in human longevity: "risk alleles" as pro-longevity variants

Complex diseases are major contributors to human mortality in old age. Paradoxically, many genetic variants that have been associated with increased risks of such diseases are found in genomes of long-lived people, and do not seem to compromise longevity. Here we argue that trade-off-like and conditional effects of genes can play central role in this phenomenon and in determining longevity. Such effects may occur as result of: (i) antagonistic influence of gene on the development of different health disorders; (ii) change in the effect of gene on vulnerability to death with age (especially, from “bad” to “good”); (iii) gene–gene interaction; and (iv) gene–environment interaction, among other factors. A review of current knowledge provides many examples of genetic factors that may increase the risk of one disease but reduce chances of developing another serious health condition, or improve survival from it. Factors that may increase risk of a major disease but attenuate manifestation of physical senescence are also discussed. Overall, available evidence suggests that the influence of a genetic variant on longevity may be negative, neutral or positive, depending on a delicate balance of the detrimental and beneficial effects of such variant on multiple health and aging related traits. This balance may change with age, internal and external environments, and depend on genetic surrounding. We conclude that trade-off-like and conditional genetic effects are very common and may result in situations when a disease “risk allele” can also be a pro-longevity variant, depending on context. We emphasize importance of considering such effects in both aging research and disease prevention.

Birth Cohort, Age, and Sex Strongly Modulate Effects of Lipid Risk Alleles Identified in Genome-Wide Association Studies

Insights into genetic origin of diseases and related traits could substantially impact strategies for improving human health. The results of genome-wide association studies (GWAS) are often positioned as discoveries of unconditional risk alleles of complex health traits. We re-analyzed the associations of single nucleotide polymorphisms (SNPs) associated with total cholesterol (TC) in a large-scale GWAS meta-analysis. We focused on three generations of genotyped participants of the Framingham Heart Study (FHS). We show that the effects of all ten directly-genotyped SNPs were clustered in different FHS generations and/or birth cohorts in a sex-specific or sex-unspecific manner. The sample size and procedure-therapeutic issues play, at most, a minor role in this clustering. An important result was clustering of significant associations with the strongest effects in the youngest, or 3rd Generation, cohort. These results imply that an assumption of unconditional connections of these SNPs with TC is generally implausible and that a demographic perspective can substantially improve GWAS efficiency. The analyses of genetic effects in age-matched samples suggest a role of environmental and age-related mechanisms in the associations of different SNPs with TC. Analysis of the literature supports systemic roles for genes for these SNPs beyond those related to lipid metabolism. Our analyses reveal strong antagonistic effects of rs2479409 (the PCSK9 gene) that cautions strategies aimed at targeting this gene in the next generation of lipid drugs. Our results suggest that standard GWAS strategies need to be advanced in order to appropriately address the problem of genetic susceptibility to complex traits that is imperative for translation to health care.

Is Post-Traumatic Stress Disorder Associated with Premature Senescence? A Review of the Literature

OBJECTIVE

Post-traumatic stress disorder (PTSD) has major public health significance. Evidence that PTSD may be associated with premature senescence (early or accelerated aging) would have major implications for quality of life and healthcare policy. We conducted a comprehensive review of published empirical studies relevant to early aging in PTSD.

METHOD

Our search included the PubMed, PsycINFO, and PILOTS databases for empirical reports published since the year 2000 relevant to early senescence and PTSD, including: 1) biomarkers of senescence (leukocyte telomere length [LTL] and pro-inflammatory markers), 2) prevalence of senescence-associated medical conditions, and 3) mortality rates.

RESULTS

All six studies examining LTL indicated reduced LTL in PTSD (pooled Cohen's d = 0.76). We also found consistent evidence of increased pro-inflammatory markers in PTSD (mean Cohen's ds), including C-reactive protein = 0.18, Interleukin-1 beta = 0.44, Interleukin-6 = 0.78, and tumor necrosis factor alpha = 0.81. The majority of reviewed studies also indicated increased medical comorbidity among several targeted conditions known to be associated with normal aging, including cardiovascular disease, type 2 diabetes mellitus, gastrointestinal ulcer disease, and dementia. We also found seven of 10 studies indicated PTSD to be associated with earlier mortality (average hazard ratio: 1.29).

CONCLUSION

In short, evidence from multiple lines of investigation suggests that PTSD may be associated with a phenotype of accelerated senescence. Further research is critical to understand the nature of this association. There may be a need to re-conceptualize PTSD beyond the boundaries of mental illness, and instead as a full systemic disorder.

Causal effects of time-dependent treatments in older patients with non-small cell lung cancer

Background

Treatment selection for elderly patients with lung cancer must balance the benefits of curative/life-prolonging therapy and the risks of increased mortality due to comorbidities. Lung cancer trials generally exclude patients with comorbidities and current treatment guidelines do not specifically consider comorbidities, so treatment decisions are usually made on subjective individual-case basis.

Methods

Impacts of surgery, radiation, and chemotherapy mono-treatment as well as combined chemo/radiation on one-year overall survival (compared to no-treatment) are studied for stage-specific lung cancer in 65+ y.o. patients. Methods of causal inference such as propensity score with inverse probability weighting (IPW) for time-independent and marginal structural model (MSM) for time-dependent treatments are applied to SEER-Medicare data considering the presence of comorbid diseases.

Results

122,822 patients with stage I (26.8%), II (4.5%), IIIa (11.5%), IIIb (19.9%), and IV (37.4%) lung cancer were selected. Younger age, smaller tumor size, and fewer baseline comorbidities predict better survival. Impacts of radio- and chemotherapy increased and impact of surgery decreased with more advanced cancer stages. The effects of all therapies became weaker after adjustment for selection bias, however, the changes in the effects were minor likely due to the weak selection bias or incompleteness of the list of predictors that impacted treatment choice. MSM provides more realistic estimates of treatment effects than the IPW approach for time-independent treatment.

Conclusions

Causal inference methods provide substantive results on treatment choice and survival of older lung cancer patients with realistic expectations of potential benefits of specific treatments. Applications of these models to specific subsets of patients can aid in the development of practical guidelines that help optimize lung cancer treatment based on individual patient characteristics.

Cardiovascular comorbidities and survival of lung cancer patients: Medicare data based analysis

OBJECTIVES

To evaluate the role of cardiovascular disease (CVD) comorbidity in survival of patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The impact of seven CVDs (at the time of NSCLC diagnosis and during subsequent follow-up) on overall survival was studied for NSCLC patients aged 65+ years using the Surveillance, Epidemiology, and End Results data linked to the U.S. Medicare data, cancer stage- and treatment-specific. Cox regression was applied to evaluate death hazard ratios of CVDs in univariable and multivariable analyses (controlling by age, TNM statuses, and 78 non-CVD comorbidities) and to investigate the effects of 128 different combinations of CVDs on patients' survival.

RESULTS

Overall, 95,167 patients with stage I (n=29,836, 31.4%), II (n=5133, 5.4%), IIIA (n=11,884, 12.5%), IIIB (n=18,020, 18.9%), and IV (n=30,294, 31.8%) NSCLC were selected. Most CVDs increased the risk of death for stages I-IIIB patients, but did not significantly impact survival of stage IV patients. The worse survival of patients was associated with comorbid heart failure, myocardial infarction, and cardiac arrhythmias that occurred during a period of follow-up: HRs up to 1.85 (p<0.001), 1.96 (p<0.05), and 1.67 (p<0.001), respectively, varying by stage and treatment. The presence of hyperlipidemia at baseline (HR down to 0.71, p<0.05) was associated with better prognosis. Having multiple co-existing CVDs significantly increased mortality for all treatments, especially for stages I and II patients treated with surgery (HRs up to 2.89, p<0.05) and stages I-IIIB patients treated with chemotherapy (HRs up to 2.59, p<0.001) and chemotherapy and radiotherapy (HRs up to 2.20, p<0.001).

CONCLUSION

CVDs impact the survival of NSCLC patients, particularly when multiple co-existing CVDs are present; the impacts vary by stage and treatment. This data should be considered in improving cancer treatment selection process for such potentially challenging patients as the elderly NSCLC patients with CVD comorbidities.

Biodemographic Analyses of Longitudinal Data on Aging, Health, and Longevity: Recent Advances and Future Perspectives

Biodemography became one of the most innovative and fastest growing areas in demography. This progress is fueled by the growing variability and amount of relevant data available for analyses as well as by methodological developments allowing for addressing new research questions using new approaches that can better utilize the potential of these data. In this review paper, we summarize recent methodological advances in biodemography and their diverse practical applications. Three major topics are covered: (1) computational approaches to reconstruction of age patterns of incidence of geriatric diseases and other characteristics such as recovery rates at the population level using Medicare claims data; (2) methodological advances in genetic and genomic biodemography and applications to research on genetic determinants of longevity and health; and (3) biodemographic models for joint analyses of time-to-event data and longitudinal measurements of biomarkers collected in longitudinal studies on aging. We discuss how such data and methodology can be used in a comprehensive prediction model for joint analyses of incomplete datasets that take into account the wide spectrum of factors affecting health and mortality transitions including genetic factors and hidden mechanisms of aging-related changes in physiological variables in their dynamic connection with health and survival.

Levodopa/benserazide microsphere (LBM) prevents L-dopa induced dyskinesia by inactivation of the DR1/PKA/P-tau pathway in 6-OHDA-lesioned Parkinson's rats

L-3, 4-dihydroxyphenylalanine (L-dopa) is the gold standard for symptomatic treatment of Parkinson's disease (PD), but long-term therapy is associated with the emergence of L-dopa-induced dyskinesia (LID). In the present study, L-dopa and benserazide were loaded by poly (lactic-co-glycolic acid) microspheres (LBM), which can release levodopa and benserazide in a sustained manner in order to continuous stimulate dopaminergic receptors. We investigated the role of striatal DR1/PKA/P-tau signal transduction in the molecular event underlying LID in the 6-OHDA-lesioned rat model of PD. We found that animals rendered dyskinetic by L-dopa treatment, administration of LBM prevented the severity of AIM score, as well as improvement in motor function. Moreover, we also showed L-dopa elicits profound alterations in the activity of three LID molecular markers, namely DR1/PKA/P-tau (ser396). These modifications are totally prevented by LBM treatment, a similar way to achieve continuous dopaminergic delivery (CDD). In conclusion, our experiments provided evidence that intermittent administration of L-dopa, but not continuous delivery, and DR1/PKA/p-tau (ser396) activation played a critical role in the molecular and behavioural induction of LID in 6-OHDA-lesioned rats. In addition, LBM treatment prevented the development of LID by inhibiting the expression of DR1/PKA/p-tau, as well as PPEB mRNA in dyskintic rats.

Going beyond the disability-based morbidity definition in the compression of morbidity framework

Background

As originally proposed by Fries, conceptualizing morbidity solely through associated functional limitation/disability (FL/D) remains the most widely accepted metric to assess whether increases in longevity have been accompanied by a compression of morbidity.

Objective

To propose a departure from a highly restrictive FL/D-based definition of “morbidity” to a broader view that considers the burden of chronic diseases even when no overt FL/D occur.

Design

We outline three reasons why the current framework of compression of morbidity should be broadened to also consider morbidity to be present even when there are no overtly measurable FL/D. We discuss various scenarios of morbidity compression and morbidity expansion under this broader rubric of morbidity.

Conclusion

The rationale to go beyond a purely FL/D-based definition of morbidity includes: (1) substantial damage from chronic disease that can develop prior to overt FL/D symptoms occurring; (2) multiple costs to the individual and society that extend beyond FL/D, including medication costs, health care visits, and opportunity costs of lifelong treatment; and (3) psychosocial and stress burden of being labeled as diseased and the consequence for overall well-being. Adopting this broader definition of morbidity suggests that increases in longevity have been possibly accompanied by an expansion of morbidity, in contrast to Fries’ original hypothesis that morbidity onset (based on only FL/D) would be delayed to a greater extent than increases in survival. There is an urgent need for better data and more research to document morbidity onset and its link with increases in longevity and assess the important question on whether populations while living longer are also healthier.

Benefit of adjuvant chemotherapy after resection of stage II (T1-2N1M0) non-small cell lung cancer in elderly patients

BACKGROUND

We evaluated the use and efficacy of adjuvant chemotherapy after resection of T1-2N1M0 non-small cell lung cancer (NSCLC) in elderly patients.

METHODS

Factors associated with the use of adjuvant chemotherapy in patients older than 65 years of age who underwent surgical resection of T1-2N1M0 NSCLC without induction chemotherapy or radiation in the Surveillance, Epidemiology, and End Results-Medicare database from 1992 to 2006 were assessed using a multivariable logistic regression model that included treatment, patient, tumor, and census tract characteristics. Overall survival (OS) was analyzed using the Kaplan-Meier approach and inverse probability weight-adjusted Cox proportional hazard models.

RESULTS

Overall, 2,781 patients who underwent surgical resection as the initial treatment for T1-2N1M0 NSCLC and survived at least 31 days after surgery were identified, with adjuvant chemotherapy given to 784 patients (28.2 %). Factors that predicted adjuvant chemotherapy use were younger age and higher T status. The 5-year OS was significantly better for patients who received adjuvant chemotherapy compared with patients not given adjuvant chemotherapy: 35.8 % (95 % confidence interval [CI] 31.9-39.6) vs. 28.0 % (95 % CI 25.9-30.0) (p = 0.008). In the inverse probability weight-adjusted Cox proportional hazard regression model, adjuvant chemotherapy use predicted significantly improved survival (hazard ratio 0.84; 95 % CI 0.76-0.92; p = 0.0002).

CONCLUSIONS

Adjuvant chemotherapy after resection of T1-2N1M0 NSCLC is associated with significantly improved survival in patients older than 65 years. These data can be used to provide elderly patients with realistic expectations of the potential benefits when considering adjuvant chemotherapy in this setting.

Continuous dopaminergic stimulation (CDS)-based treatment in Parkinson's disease patients with motor complications: a systematic review and meta-analysis

A systematic review of the literature was conducted to identify randomized trials involving continuous dopaminergic stimulation (CDS) in PD patients with motor complications. Difference between n groups was assessed by partitioning heterogeneity and using the χ2 distribution with n-1 degrees of freedom, where n equals the number of groups. We looked for publication bias using funnel plotting, Egger's test and Begg's test. Twenty Randomized Controlled Trials (RCTs) were included. The results showed that CDS could evidently improve the Unified Parkinson's Disease Rating Scale (UPDRS) Part II (p < 0.0001), part III (P < 0.00001) and UPDRS total score (p < 0.00001). There was also a statistical discrepancy in off time reduction (p < 0.00001) and prolongation of on time (p < 0.00001) by the CDS therapy compared with control groups. Meanwhile, the results of this study showed obvious side effects in the CDS therapy compared with the placebo, especially at the expense of increased dyskinesia (23.4% vs 11.7%). The present study showed that CDS was beneficial in the treatment of PD patients with motor complications. But the incidence of the side events is more common than placebo.

Unraveling genetic origin of aging-related traits: evolving concepts

Discovering the genetic origin of aging-related traits could greatly advance strategies aiming to extend health span. The results of genome-wide association studies (GWAS) addressing this problem are controversial, and new genetic concepts have been fostered to advance the progress in the field. A limitation of GWAS and new genetic concepts is that they do not thoroughly address specifics of aging-related traits. Integration of theoretical concepts in genetics and aging research with empirical evidence from different disciplines highlights the conceptual problems in studies of genetic origin of aging-related traits. To address these problems, novel approaches of systemic nature are required. These approaches should adopt the non-deterministic nature of linkage of genes with aging-related traits and, consequently, reinforce research strategies for improving our understanding of mechanisms shaping genetic effects on these traits. Investigation of mechanisms will help determine conditions that activate specific genetic variants or profiles and explore to what extent these conditions that shape genetic effects are conserved across human lives and generations.

Atherosclerotic Cardiovascular Disease Risk and Evidence-based Management of Cholesterol

An elevated level of low-density lipoprotein cholesterol is directly associated with development of atherosclerotic cardiovascular disease, which may present as coronary heart disease, stroke, and peripheral arterial disease. The new cholesterol management guidelines from the American College of Cardiology and the American Heart Association aim to address a comprehensive approach to prevent and reduce the risk of atherosclerotic cardiovascular disease. The new guidelines recommend initiation of heart healthy lifestyle modifications and 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor ("statin") therapy in individuals who are at a high risk for atherosclerotic cardiovascular disease. It is estimated that these guidelines could result in "statin" therapy for one in every three adults in the United States. This article presents a review of the current cholesterol management guidelines, recommendations from relevant randomized controlled trials and meta-analyses obtained from the searches in Medline/PubMed and Cochrane Database of Systematic Reviews, and publications from the Centers for Disease Control and Prevention, the Centers for Medicare and Medicaid Service, and the United States Preventive Services Task Force.

Differences in the symptom experience of older oncology outpatients

CONTEXT

The relatively low number of older patients in cancer trials limits knowledge of how older adults experience symptoms associated with cancer and its treatment.

OBJECTIVES

This study evaluated for differences in the symptom experience across four older age groups (60-64, 65-69, 70-74, ≥75 years).

METHODS

Demographic, clinical, and symptom data from 330 patients aged >60 years who participated in one Australian and two U.S. studies were evaluated. The Memorial Symptom Assessment Scale was used to evaluate the occurrence, severity, frequency, and distress of 32 symptoms commonly associated with cancer and its treatment.

RESULTS

On average, regardless of the age group, patients reported 10 concurrent symptoms. The most prevalent symptoms were physical in nature. Worrying was the most common psychological symptom. For 28 (87.5%) of the 32 Memorial Symptom Assessment Scale symptoms, no age-related differences were found in symptom occurrence rates. For symptom severity ratings, an age-related trend was found for difficulty swallowing. As age increased, severity of difficulty swallowing decreased. For symptom frequency, age-related trends were found for feeling irritable and diarrhea, with both decreasing in frequency as age increased. For symptom distress, age-related trends were found for lack of energy, shortness of breath, feeling bloated, and difficulty swallowing. As age increased, these symptoms received lower average distress ratings.

CONCLUSION

Additional research is warranted to examine how age differences in symptom experience are influenced by treatment differences, aging-related changes in biological or psychological processes, or age-related response shift.

Variability in the treatment of elderly patients with stage IIIA (N2) non-small-cell lung cancer

INTRODUCTION

: We evaluated treatment patterns of elderly patients with stage IIIA (N2) non-small-cell lung cancer (NSCLC).

METHODS

: The use of surgery, chemotherapy, and radiation for patients with stage IIIA (T1-T3N2M0) NSCLC in the Surveillance, Epidemiology, and End Results-Medicare database from 2004 to 2007 was analyzed. Treatment variability was assessed using a multivariable logistic regression model that included treatment, patient, tumor, and census track variables. Overall survival was analyzed using the Kaplan-Meier approach and Cox proportional hazard models.

RESULTS

: The most common treatments for 2958 patients with stage IIIA (N2) NSCLC were radiation with chemotherapy (n = 1065, 36%), no treatment (n = 534, 18%), and radiation alone (n = 383, 13%). Surgery was performed in 709 patients (24%): 235 patients (8%) had surgery alone, 40 patients (1%) had surgery with radiation, 222 patients had surgery with chemotherapy (8%), and 212 patients (7%) had surgery, chemotherapy, and radiation. Younger age (p < 0.0001), lower T-status (p < 0.0001), female sex (p = 0.04), and living in a census track with a higher median income (p = 0.03) predicted surgery use. Older age (p < 0.0001) was the only factor that predicted that patients did not get any therapy. The 3-year overall survival was 21.8 ± 1.5% for all patients, 42.1 ± 3.8% for patients that had surgery, and 15.4 ± 1.5% for patients that did not have surgery. Increasing age, higher T-stage and Charlson Comorbidity Index, and not having surgery, radiation, or chemotherapy were all risk factors for worse survival (all p values < 0.001).

CONCLUSIONS

: Treatment of elderly patients with stage IIIA (N2) NSCLC is highly variable and varies not only with specific patient and tumor characteristics but also with regional income level.