Fetal origins-A life cycle model of health and aging from conception to death

Molecular Regulation of Fetal Brain Development in Inbred and Congenic Mouse Strains Differing in Longevity

The objective of this study was to investigate gene regulation of the developing fetal brain from congenic or inbred mice strains that differed in longevity. Gene expression and alternative splice variants were analyzed in a genome-wide manner in the fetal brain of C57BL/6J mice (long-lived) in comparison to B6.Cg-Cav1tm1Mls/J (congenic, short-lived) and AKR/J (inbred, short-lived) mice on day(d) 12, 15, and 17 of gestation. The analysis showed a contrasting gene expression pattern during fetal brain development in these mice. Genes related to brain development, aging, and the regulation of alternative splicing were significantly differentially regulated in the fetal brain of the short-lived compared to long-lived mice during development from d15 and d17. A significantly reduced number of splice variants was observed on d15 compared to d12 or d17 in a strain-dependent manner. An epigenetic clock analysis of d15 fetal brain identified DNA methylations that were significantly associated with single-nucleotide polymorphic sites between AKR/J and C57BL/6J strains. These methylations were associated with genes that show epigenetic changes in an age-correlated manner in mice. Together, the finding of this study suggest that fetal brain development and longevity are epigenetically linked, supporting the emerging concept of the early-life origin of longevity.

The Childhood Opportunity Index's Association with Adverse Pregnancy and Newborn Outcomes in Nulliparous Persons

OBJECTIVE

 The objective of the study was to determine if using a novel measure of social determinants of health, the Childhood Opportunity Index (COI), at the time of delivery was associated with development of adverse pregnancy outcomes (APO) in nulliparous pregnant persons.

STUDY DESIGN

 Data were extracted from the 779 participants from a single nuMoM2b (Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be) study site, a prospective cohort study designed to identify contributors to APOs. Residential address information at delivery was linked to the location's COI. The overall composite and component scores in education, health and environmental, and socioeconomic indices were recorded. APOs of interest included preterm birth, hypertensive disorders of pregnancy, small for gestational age at birth, stillbirth, and gestational diabetes. Participant characteristics were compared by COI category and the association of COI with APOs was analyzed by logistic regression, controlling for age and self-reported race/ethnicity.

RESULTS

 The overall COI distribution was very low (45%), low (17%), moderate (10%), high (15%), and very high (13%). A total of 329 (43.5%) participants experienced at least one APO. Overall COI was associated with developing an APO (p = 0.02). Each component score was also associated with developing APOs and with race/ethnicity (p < 0.05). Compared with higher COI categories, an overall low or very low categorized location was independently associated with developing an APO (odds ratio: 1.636, 95% confidence interval: 1.16-2.31). Adjusting for gestational age at birth, those in lower COI areas had newborns with lower birth weight, birth length, and head circumference (estimate [95% confidence interval] birth weight: -0.0005 g [-0.0008 to -0.0001]; length: -0.065 cm [-0.124 to -0.0091]; head circumference: -0.123 cm [-0.208 to -0.045]). COI was not associated with other newborn outcomes.

CONCLUSION

 COI, a marker for social determinants of health, is independently associated with APOs. The COI may be a tool for risk stratification for pregnant people to help with APO-reducing strategies.

KEY POINTS

· The COI is a neighborhood-level marker for social determinants of health.. · The COI at time of delivery is associated with APO and newborn birth weight, length, and head circumference.. · The COI may be usable in pregnancy clinics to help identify resource needs to optimize outcomes for pregnant individuals and newborns..

The economics of aging with infectious and chronic diseases

We develop an economic model of aging in which the susceptibility and severity of infectious diseases depend on the accumulated health deficits (immunosenescence) and the life history of infections affects the accumulation of chronic health deficits (inflammaging). Individuals invest in their health to slow down health deficit accumulation and take measures to protect themselves from infectious diseases. We calibrate the model for an average American and explore how health expenditure, life expectancy, and the value of life depend on individual characteristics, medical technology, and the disease environment. We then use counterfactual computational experiments of the U.S. epidemiological transition 1860-2010 to show that the decline of infectious diseases caused a substantial decline of chronic diseases and contributed more to increasing life expectancy than advances in the treatment of chronic diseases.

Physiological aging and life-cycle labor supply across countries

We construct a cohort-based frailty index for 180 countries over the period 1990-2019. We use this measure of physiological aging to estimate the impact of deteriorating health on labor force participation. Our three-dimensional panel framework, in which the unit of observation is a cohort in a given country at a given age, allows us to control for a range of unobserved factors. Our identification strategy further exploits a compensating law of physiological aging to account for reverse causality. We find a negative effect of physiological aging on labor market participation: an increase of the frailty index by one percent leads to a reduction of labor force participation of about 0.6 (±0.2) percentage points. Since health deficits (in the frailty index) are accumulated at a rate of about 3 percent per year of life, almost all of the age-related decline in labor force participation can be motivated by deteriorating health.

Hooked on weight control: An economic theory of anorexia nervosa and its impact on health and longevity

In this paper, I integrate a theory of body image, weight control, and addiction in a life cycle model with health deficit accumulation in order to explain the phenomenon of anorexia nervosa and its impact on health and longevity. Individuals consume normal goods and foods and can work off excess calories with physical exercise. There exists a healthy body mass index and deviations from it increasingly cause health deficits due to obesity or underweight. There exists also a subjective target weight and being heavier than target weight causes a loss of utility from body image. Anorexia is initiated in individuals who are particularly successful in weight control and prone to addiction. Addiction to weight control motivates anorexic individuals to perpetually adjust their target weight downwards and to eat less and exercise more. With declining weight, health deficits accumulate faster and mortality risk rises. I calibrate the model to an average American woman with bmi 28. Due to weight loss addiction, the bmi declines to a level of 15 and causes an expected loss of 15 years of life. I also discuss potential therapies and recovery from the disease.

Latent Classification Analysis of Leisure Activities and Their Impact on ADL, IADL and Cognitive Ability of Older Adults Based on CLHLS (2008-2018)

This study aimed to research the trajectory of leisure activity and the health status of older adults and analyze the effects of leisure activity on the health status of older adults. Based on the longitudinal data of CLHLS (2008-2018), the latent growth curve model (LGCM) was used; we found that the leisure activities (LA), activities of daily living (ADL) ability, instrumental activities of daily living (IADL) ability, and cognitive ability (COG) of older adults show a nonlinear downward trend over time. Furthermore, the panel binary regression analysis is used to find that leisure activities have significant inhibitory effects on ADL disorder, IADL disorder, and cognitive impairment in the older population. In addition, by using latent profile analysis (LPA), the older population is classified into three groups according to the homogeneity of the older adults' choice of leisure activities, namely the types of relaxation, entertainment, and intellectual-learning, respectively. Based on the classification results, the analysis of one-way ANOVA shows that the rates of ADL disorder, IADL disorder, and cognitive impairment of older adults with different types are significantly different. Moreover, the inhibitory effect of leisure activities on the rate of ADL disorder, IADL disorder, and cognitive impairment of older adults is more significant in the middle-aged and high-aged groups. Therefore, older adults should be encouraged to increase leisure activities, especially those who are middle-aged and high-aged.

A Unified Model of Cohort Mortality

We propose a dynamic production function of population health and mortality from birth onward. Our parsimonious model provides an excellent fit for the mortality and survival curves for primate and human populations since 1816. The model sheds light on the dynamics behind many phenomena documented in the literature. Simple extensions of the model can reproduce (1) the existence and evolution of mortality gradients across socioeconomic statuses documented in the literature, (2) nonmonotonic dynamic effects of in utero shocks, (3) persistent or scarring effects of wars, and (4) mortality displacement after large temporary shocks, such as extreme weather.

The demand for health turns 50: Reflections

The year 2022 is the 50th anniversary of the publication of my demand for health model in "On the Concept of Health Capital and the Demand for Health," Journal of Political Economy 80(2): 223-255, and in The Demands for Health: A Theoretical and Empirical Investigation, NBER Occasional Paper 119 New York: Columbia University Press for the NBER. To mark that occasion, this editorial focuses on the history of the model and its impacts on the field of health economics.

A health economic theory of occupational choice, aging, and longevity

In this paper, I propose a life cycle model of occupational choice with endogenous health behavior, aging, and longevity. Health-demanding work leads to a faster accumulation of health deficits and is remunerated with a hazard markup on wages. Health deficit accumulation is also influenced by unhealthy consumption and health care expenditure. I calibrate the model for a 20 year old average American in 2010 and show the following results, among others. Health-demanding work is ceteris paribus preferred by male, young, and healthy individuals with a relatively low level of education. Health demanding work has a negligible effect on health behavior because income and health investment effects largely offset each other, implying that health effects can be attributed almost fully to the direct health burden of work. Better medical technology induces low-skilled individuals to spend a greater part of their life in health-demanding work and thus increases the health gradient of education. High wealth endowments protect against unhealthy occupational choices. I show robustness of the results in an extension of the model with regard to endogenous retirement.

Social vulnerability and aging of elderly people in the United States

We use 7 waves of the Health and Retirement Study and construct a social vulnerability index (SVI) for elderly U.S. Americans (born 1913–1966). We show that the SVI is mildly larger for men than for women and increases in age from above age 60 onwards for both genders. Social vulnerability of men (but not of women) is lower in the West and Midwest than in other regions and higher income mildly reduces the SVI for men (but not for women). In cohort analysis we find an increase of the SVI for individuals born in the late 1940s or later, which is, however, statistically significant only for women. In order to investigate the nexus between social vulnerability and aging, we construct a frailty index from the same data. We find that socially vulnerable persons display more health deficits at any age. Using the initial SVI (at first interview) we find that social vulnerability exerts a significant impact on subsequent accumulation of health deficits, which is of about the same size for men and women. A one standard deviation increase in the initial SVI leads to a 20 percent increase of the frailty index at any age.

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Panel study of social vulnerability and aging in the U.S.

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Social vulnerability index (SVI) increases for women born after 1940.

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Strong impact of initial SVI on subsequent accumulation of health deficits.

From pain patient to junkie: An economic theory of painkiller consumption and its impact on wellbeing and longevity

In this paper, I propose a life cycle model of painkiller consumption that combines the theory of health deficit accumulation with the theory of addiction. Chronic pain is conceptualized as a persistent negative shock to lifetime utility that can be treated by pain relief medication. Individuals treated with opioid pain relievers (OPR) develop addiction, which increases their demand for opioids and reduces their welfare and life expectancy through side effects and potential overdose. I calibrate the model for a benchmark American and investigate the comparative dynamics of alternative drug characteristics, pain intensities, and ages of onsets of pain as well as their implications for welfare and life expectancy. Computational experiments are used to identify fully rational and imperfectly rational addiction behavior. Fully rational addicts reduce OPR use when new information about the addictive potential of these drugs arrives. Imperfectly rational addicts further develop their addiction and switch to illicit opioid use. Likewise, a discontinued prescription helps fully rational addicts to quit quickly, while it induces imperfectly rational individuals to take up heroin. I also discuss treatment of OPR addiction and the use of opioids in palliative care.

Time-inconsistent health behavior and its impact on aging and longevity

We integrate time-inconsistent decision making due to hyperbolic discounting into a gerontologically founded life cycle model with endogenous aging and longevity. Individuals can slow down aging and postpone death by health investments and by reducing unhealthy consumption, conceptualized as smoking. We show that individuals continuously revise their original plans to smoke less and invest more in their health. Consequently, they accumulate health deficits faster and die earlier than originally planned. This fundamental health consequence of time-inconsistency has not been addressed in the literature so far. Because death is endogenous, any attempt to establish the time-consistent first-best solution by manipulating the first order conditions through (sin-) taxes and subsidies is bound to fail. We calibrate the model with U.S. data for an average American in the year 2012 and estimate that time-inconsistent health behavior causes a loss of about 4 years of life. We show how price policy can nudge individuals to behave more healthy such that they actually realize the longevity and value of life planned at age 20.