Changing Impact of Obesity on Active Life Expectancy of Older Americans

Cross-sectional and longitudinal associations of obesity with disability between age 50 and 90 in the SHARE study

BACKGROUND

Obesity is associated with disability but whether age and ageing modify this association remains unclear. We examined whether this association changes between 50 and 90 years, and whether change in disability rates over 14 years differs by body mass index (BMI) categories.

METHODS

BMI and ADL-disability data on 28,453 individuals from 6 waves (2004-2018, SHARE study) were used to examine the cross-sectional absolute and relative associations, extracted at age 50, 60, 70, 80, and 90 years using logistic mixed models. Then baseline BMI and change in disability rates over 14-years were examined using logistic-mixed models.

RESULTS

At age 50, the probabilities of ADL disability in individuals with BMI 30-34.9 and ≥35 kg/m² were 0.07 (0.06, 0.09) and 0.11 (0.09, 0.12), increasing to 0.47 (0.44, 0.50) and 0.55 (0.50, 0.60) at age 90; the increase in both these groups was greater than that in the normal-weight group (p for increase with age<0.001). On the relative scale the OR at age 50 in these obesity groups was 2.37 (1.79, 3.13) and 5.03 (3.38, 7.48), decreasing to 1.51 (1.20, 1.89) and 2.19 (1.50, 3.21) at age 90; p for decrease with age=0.05 and 0.02 respectively. The 14-year increase in probability of disability was greatest in those with BMI≥35 kg/m² at age 50, 60, and 70 at baseline: differences in increase compared to normal weight were 0.08 (0.02, 0.14), 0.11 (0.07, 0.15), and 0.09 (0.02, 0.16) respectively.

CONCLUSIONS

ADL disability is increasingly prevalent with age in individuals with obesity. Relative measures of change obscure the association between obesity and disability due to age-related increase in disability rates in all groups.

Dietary kaempferol exerts anti-obesity effects by inducing the browing of white adipocytes via the AMPK/SIRT1/PGC-1α signaling pathway

Browning of white adipose tissue is a novel approach for the management of obesity and obesity-related metabolic disorders. Kaempferol (KPF) is a common dietary nutrient found abundantly in many fruits and vegetables and has been shown to have the potential to regulate lipid metabolism. However, the detailed mechanism by which it affects the browning of white adipose tissue remains unclear. In the present study, we sought to determine how KPF induces adipocytes to undergo a browning transformation by establishing a primary adipocyte model and an obese mouse model. Our results showed that KPF-treated mice were rescued from diet-induced obesity, glucose tolerance and insulin resistance, associated with increased expression of adaptive thermogenesis-related proteins. KPF-promoted white adipose browning correlated with the AMPK/SIRT1/PGC-1α pathway, as the use of an AMPK inhibitor in preadipocytes partially reversed the observed browning phenotype of KPF-treated cells. Taken together, these data suggest that KPF promotes browning of white adipose tissue through activation of the AMPK/SIRT1/PGC-1α pathway. This study demonstrates that KPF is a promising natural product for the treatment of obesity by promoting white fat browning.

Dual Functionality in Later Life

Gerontologists have long shown interest in both longevity and quality of life during later life, but considerable debate has ensued as scholars sought to integrate the two. Drawing from research on the topics of exceptional longevity, successful aging, and active life expectancy, we propose the concept of dual functionality to examine how humans reach advanced ages while maintaining physical and cognitive function. Dual functionality refers to being free of both physical and cognitive impairment. The loss of dual functionality challenges social networks to respond to the functional loss and is a harbinger of additional losses. Evidence of change in the percent of the older population maintaining dual functionality would be helpful for evaluating public health policies to aid quality of life during later life. This article is based on the first author's Robert W. Kleemeier Award Lecture at The Gerontological Society of America 2022 Annual Scientific Meeting.

Body mass index and all-cause mortality in a 21st century U.S. population: A National Health Interview Survey analysis

INTRODUCTION

Much of the data on BMI-mortality associations stem from 20th century U.S. cohorts. The purpose of this study was to determine the association between BMI and mortality in a contemporary, nationally representative, 21st century, U.S. adult population.

METHODS

This was a retrospective cohort study of U.S. adults from the 1999-2018 National Health Interview Study (NHIS), linked to the National Death Index (NDI) through December 31st, 2019. BMI was calculated using self-reported height & weight and categorized into 9 groups. We estimated risk of all-cause mortality using multivariable Cox proportional hazards regression, adjusting for covariates, accounting for the survey design, and performing subgroup analyses to reduce analytic bias.

RESULTS

The study sample included 554,332 adults (mean age 46 years [SD 15], 50% female, 69% non-Hispanic White). Over a median follow-up of 9 years (IQR 5-14) and maximum follow-up of 20 years, there were 75,807 deaths. The risk of all-cause mortality was similar across a wide range of BMI categories: compared to BMI of 22.5-24.9 kg/m2, the adjusted HR was 0.95 [95% CI 0.92, 0.98] for BMI of 25.0-27.4 and 0.93 [0.90, 0.96] for BMI of 27.5-29.9. These results persisted after restriction to healthy never-smokers and exclusion of subjects who died within the first two years of follow-up. A 21-108% increased mortality risk was seen for BMI ≥30. Older adults showed no significant increase in mortality between BMI of 22.5 and 34.9, while in younger adults this lack of increase was limited to the BMI range of 22.5 to 27.4.

CONCLUSION

The risk of all-cause mortality was elevated by 21-108% among participants with BMI ≥30. BMI may not necessarily increase mortality independently of other risk factors in adults, especially older adults, with overweight BMI. Further studies incorporating weight history, body composition, and morbidity outcomes are needed to fully characterize BMI-mortality associations.

Improving Older Adults' Health by Reducing Administrative Burden

Policy Points Administrative burdens, which are the onerous experiences people have when trying to access government benefits and services, reduce older adult's access to health promoting policies. Although considerable attention has been focused on threats to the old-age welfare state, ranging from long-term financing problems to attempts to roll back benefits, administrative barriers to these programs already threaten their effectiveness. Reducing administrative burden is a viable way to improve population health among older adults going forward over the next decade.

Educational Differences in Life Expectancies With and Without Pain

OBJECTIVES

This study computes years and proportion of life that older adults living in the United States can expect to live pain-free and in different pain states, by age, sex, and level of education. The analysis addresses challenges related to dynamics and mortality selection when studying associations between education and pain in older populations.

METHODS

Data are from National Health and Aging Trends Study, 2011-2020. The sample contains 10,180 respondents who are age 65 and older. Pain expectancy estimates are computed using the Interpolated Markov Chain software that applies probability transitions to multistate life tables.

RESULTS

Those with higher educational levels expect not only a longer life but also a higher proportion of life without pain. For example, a 65-year-old female with less than high school education expects 18.1 years in total and 5.8 years, or 32% of life, without pain compared with 23.7 years in total with 10.7 years, or 45% of life without pain if she completed college. The education gradient in pain expectancies is more salient for females than males and narrows at the oldest ages. There is no educational disparity in the percent of life with nonlimiting pain.

DISCUSSION

Education promotes longer life and more pain-free years, but the specific degree of improvement by education varies across demographic groups. More research is needed to explain associations between education and more and less severe and limiting aspects of pain.

An exploration of the challenges of providing person-centred care for older care home residents with obesity

The aim of this study was to explore care home staff's views on the prevalence of obesity in older people and how well prepared they were for any rise in applications for placements. Thematic analysis was used to analyse focus group interview data collected from seven care homes/33 participants in N.E. England. Findings revealed rises in demand by older people with obesity for care home admittance, consistent with rising prevalence of obesity in this demographic nationally. Findings also highlight implications of rising prevalence of obesity in older people, particularly care home staff's ability to deliver person-centred care (PCC) and the importance of appropriate support/recognition of this as an emergent issue to be addressed at a higher executive level and by health/social care authorities. Ways of ensuring PCC are discussed. Given continuing trends towards rising prevalence of obesity in this population, the findings possess broader translational potential.

Association between self-reported body mass index and active life expectancy in a large community-dwelling sample of older U.S. adults

Background

Obesity may have a protective effect (greater survival) in older adults, a finding known as the “obesity paradox.” This study examined the association between self-reported body mass index (BMI) and active life expectancy (ALE) among older U.S. adults.

Methods

Using the Medicare Health Outcomes Survey Cohort 15 (2012 baseline, 2014 follow-up), we estimated life expectancy and ALE by participants’ baseline BMI and age using multi-state models. A participant was classified as in an active state if this person reported having no difficulty for any of these six activities of daily living (ADLs).

Results

Small differences in life expectancy were noted among persons in normal weight (BMI 18.5–24.9 kg/m²), overweight (BMI 25–29.9 kg/m²), and obesity ranges (BMI 30 kg/m² and higher). However, persons with obesity had a significantly lower ALE. ALE at age 65 was 11.1 (11.0–11.2) years for persons with obesity, 1.2 (1.1–1.3) years less than that for the normal weight and overweight persons (12.3 years for both, 12.2–12.4). Persons with class III obesity had a significantly lower life expectancy and ALE than normal weight persons. Although persons with class I or II obesity had a similar life expectancy as normal weight persons, they have a shorter ALE.

Conclusions

Although older adults with obesity have a similar life expectancy as normal weight persons, they have a significantly shorter ALE. Given the complex relationship of BMI and ALE, a “one size fits all” approach to weight management is not advisable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03021-7.

Population-level impact of adverse early life conditions on adult healthy life expectancy in low- and middle-income countries

Evidence from theories of Developmental Origins of Health and Disease (DOHaD) suggests that experiencing adverse early life conditions subsequently leads to detrimental adult health outcomes. The bulk of empirical DOHaD literature does not consider the nature and magnitude of the impact of adverse early life conditions at the population level. In particular, it ignores the distortion of age and cohort patterns of adult health and mortality and the increased load of chronic illness and disability that ensues. In this paper, we use a microsimulation model combined with empirical estimates of incidence and prevalence of obesity, type 2 diabetes, and associated disability in low- and middle-income countries to assess the magnitude of delayed effects on adult healthy life expectancy and on compression (or expansion) of morbidity at older ages. The main goal is to determine if, in what ways, and to what extent delayed effects due to early conditions can influence cohorts' chronic illness and disability profiles.

Population-level impact of adverse early life conditions on adult healthy life expectancy in low- and middle-income countries

Evidence from theories of Developmental Origins of Health and Disease (DOHaD) suggests that experiencing adverse early life conditions subsequently leads to detrimental adult health outcomes. The bulk of empirical DOHaD literature does not consider the nature and magnitude of the impact of adverse early life conditions at the population level. In particular, it ignores the distortion of age and cohort patterns of adult health and mortality and the increased load of chronic illness and disability that ensues. In this paper, we use a microsimulation model combined with empirical estimates of incidence and prevalence of obesity, type 2 diabetes, and associated disability in low- and middle-income countries to assess the magnitude of delayed effects on adult healthy life expectancy and on compression (or expansion) of morbidity at older ages. The main goal is to determine if, in what ways, and to what extent delayed effects due to early conditions can influence cohorts' chronic illness and disability profiles.

Changes in Body Composition in Older Adults after a Technology-Based Weight Loss Intervention

We conducted a post-hoc analysis of a pre/post, single-arm, non-randomized, multicomponent weight loss intervention in older adults. Fifty-three older adults aged ≥65 with a body mass index ≥ 30 kg/m2 were recruited to participate in a six-month, remote monitoring and video-conferencing delivered, prescriptive intervention consisting of individual and group-led registered dietitian nutrition and physical therapy sessions. We assessed weight, height, and body composition using a SECA 514 bioelectrical impedance analyzer. Mean age was 72.9±3.9 years (70% female) and all had ≥2 chronic conditions. Of those with complete data (n=30), we observed a 4.6±3.5kg loss in weight, 6.1±14.3kg (1.9%) loss in fat mass, and 0.78±1.69L loss in visceral fat (all p<0.05). Fat-free mass (-3.4kg±6.8, p=0.19), appendicular lean mass (-0.25±1.83, p=0.22), and grip strength (+3.46±7.89, p=0.56) did not significantly change. These variables were preserved after stratifying by 5% weight loss. Our intervention led to significant body and visceral fat loss while maintaining fat-free and appendicular lean muscle mass.

The Role of Underweight in Active Life Expectancy Among Older Adults in Japan

OBJECTIVES

It is underweight, rather than overweight or obesity, that has been a pressing public health concern in Japan. This study examines the impact of being underweight on the health of older Japanese men and women, measured by active life expectancy at age 65. Following the Japanese government's guideline, underweight in this study is defined using the body mass index (BMI) value of 20.

METHOD

Data came from five waves (1999-2009) of the Nihon University Japanese Longitudinal Study of Aging (NUJLSOA). We used the Interpolation of Markov Chain approach to estimate the number of years underweight (BMI < 20), normal weight (20 < BMI < 25), and overweight (25 < BMI) individuals were expected to live without difficulty in activities of daily living (ADLs) or instrumental ADLs.

RESULTS

We found differences in life and health expectancies across the three weight categories. Underweight people were expected to live the shortest lives and spend the fewest years in an active state compared with normal and overweight individuals. Results remained unchanged even when accounting for educational attainment, smoking history, and a count of existing chronic conditions.

DISCUSSION

Being underweight is associated with poor quality of life lived among Japanese older adults. This finding suggests the importance of maintaining proper weight and avoids nutritional risks at advanced ages.

Socioeconomic Inequalities in Disability-free Life Expectancy in Older People from England and the United States: A Cross-national Population-Based Study

Background

We examined socioeconomic inequalities in disability-free life expectancy in older men and women from England and the United States and explored whether people in England can expect to live longer and healthier lives than those in the United States.

Methods

We used harmonized data from the Gateway to Global Aging Data on 14,803 individuals aged 50+ from the U.S. Health and Retirement Study (HRS) and 10,754 from the English Longitudinal Study of Ageing (ELSA). Disability was measured in terms of impaired activities and instrumental activities of daily living. We used discrete-time multistate life table models to estimate total life expectancy and life expectancy free of disability.

Results

Socioeconomic inequalities in disability-free life expectancy were of a similar magnitude (in absolute terms) in England and the United States. The socioeconomic disadvantage in disability-free life expectancy was largest for wealth, in both countries: people in the poorest group could expect to live seven to nine fewer years without disability than those in the richest group at the age of 50.

Conclusions

Inequalities in healthy life expectancy exist in both countries and are of similar magnitude. In both countries, efforts in reducing health inequalities should target people from disadvantaged socioeconomic groups.

Hypothalamic gene transfer of BDNF promotes healthy aging

The aging process and age-related diseases all involve metabolic decline and impaired ability to cope with adversity. Environmental enrichment (EE)-a housing environment which recapitulates aspects of active lifestyle-exerts a wide range of health benefits in laboratory rodents. Brain-derived neurotrophic factor (BDNF) in the hypothalamus orchestrates autonomic and neuroendocrine processes, serving as one key brain mediator of EE-induced resistance to obesity, cancer, and autoimmunity. Recombinant adeno-associated virus (AAV)-mediated hypothalamic BDNF gene transfer alleviates obesity, diabetes, and metabolic syndromes in both diet-induced and genetic models. One recent study by our lab demonstrates the efficacy and safety of a built-in autoregulatory system to control transgene BDNF expression, mimicking the body's natural feedback systems in middle-age mice. Twelve-month old mice were treated with autoregulatory BDNF vector and monitored for 7months. BDNF gene transfer prevented age-associated metabolic decline by: reducing adiposity, preventing the decline of brown fat activity, increasing adiponectin while reducing leptin and insulin in circulation, improving glucose tolerance, increasing energy expenditure, alleviating hepatic steatosis, and suppressing inflammatory genes in the hypothalamus and adipose tissues. Furthermore, BDNF treatment reduced anxiety-like and depression-like behaviors. This chapter summarizes this work and discusses potential roles that hypothalamic BDNF might play in promoting healthy aging.

The Impact of Smoking and Obesity on Disability-Free Life Expectancy in Older Australians

BACKGROUND

Smoking and obesity are 2 modifiable risk factors for disability. We examine the impact of smoking and obesity on disability-free life expectancy (DFLE) at older ages, using 2 levels of disability.

METHOD

We used the DYNOPTA dataset, derived by harmonizing and pooling risk factors and disability outcomes from 5 Australian longitudinal aging studies. We defined mobility disability as inability to walk 1 km, and more severe (activities of daily living [ADL]) disability by the inability to dress or bathe. Mortality data for the analytic sample (N = 20 401; 81.2% women) were obtained from Government Records via data linkage. We estimated sex-specific total life expectancy, DFLE, and years spent with disability by Interpolated Markov Chain (IMaCh) software for each combination of smoking (never vs ever), obesity (body mass index ≥30 vs 18.5 to <30), and education (left school age 14 or younger vs age 15 or older).

RESULTS

Compared to those without either risk factor, high educated nonobese smokers at age 65 lived shorter lives (men and women: 2.5 years) and fewer years free of mobility disability (men: 2.1 years; women: 2.0 years), with similar results for ADL disability. Obesity had the largest effect on mobility disability in women; high educated obese nonsmoking women lived 1.3 years less than nonsmoking, not obese women but had 5.1 years fewer free of mobility disability and 3.2 fewer free of ADL disability. Differences between risk factor groups were similar for the low educated.

CONCLUSIONS

Our findings suggest eliminating obesity would lead to an absolute reduction of disability, particularly in women.

The COVID-19 Pandemic: Lessons for Financially Fragile and Aging Societies

The current COVID-19 crisis teaches organizations and households harsh lessons about the necessity of having buffers, to deal with the consequences of the COVID-19 virus. The financial fragility of households and the rising proportion of people becoming obese calls for intensified efforts, both by individuals and employers to create financial buffers and keep on investing in health. The financial fragility of organizations is a wake-up call that a short-term focus on efficiency can be counterproductive and may overturn the efforts to start working longer.