The obesity paradox is mostly driven by decreased noncardiovascular disease mortality in the oldest old in China: a 20-year prospective cohort study

Metabolic obesity phenotypes and all-cause mortality among the Chinese oldest-old population: a prospective cohort study

BACKGROUND

The obesity paradox has been reported among older adults. However, whether the favorable effect of obesity is dependent on metabolic status remains largely unknown. We aimed to explore the association of metabolic obesity phenotypes and their changes with all-cause mortality among the Chinese oldest-old population.

METHODS

This prospective cohort study included 1207 Chinese oldest old (mean age: 91.8 years). Metabolic obesity phenotypes were determined by central obesity and metabolic status, and participants were classified into metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy non-obesity (MHN), and metabolically unhealthy non-obesity (MUN). The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by Cox regression models.

RESULTS

During 5.3 years of follow-up, 640 deaths were documented. Compared with non-obesity, obesity was associated with a decreased mortality risk among participants with metabolically healthy (HR, 0.75; 95% CI, 0.63-0.91) while this association was insignificant among metabolically unhealthy. Compared to MHO, MHN (HR, 1.27; 95% CI, 1.06-1.53) and MUN (HR, 1.49; 95% CI, 1.10-2.02) were significantly associated with an increased mortality risk. Compared to those with stable MHO, those transited from MHO to MUO demonstrated a higher mortality risk (HR, 1.81; 95% CI, 1.06-3.11).

CONCLUSIONS

MHO predicts better survival among the Chinese oldest-old population. These findings suggest that ensuring optimal management of metabolic health is beneficial and taking caution in weight loss based on the individual body weight for the metabolically healthy oldest-old adults.

Identifying potential causal effects of Parkinson's disease: A polygenic risk score-based phenome-wide association and mendelian randomization study in UK Biobank

There is considerable uncertainty regarding the associations between various risk factors and Parkinson's Disease (PD). This study systematically screened and validated a wide range of potential PD risk factors from 502,364 participants in the UK Biobank. Baseline data for 1851 factors across 11 categories were analyzed through a phenome-wide association study (PheWAS). Polygenic risk scores (PRS) for PD were used to diagnose Parkinson's Disease and identify factors associated with PD diagnosis through PheWAS. Two-sample Mendelian randomization (MR) analysis was employed to assess causal relationships. PheWAS results revealed 267 risk factors significantly associated with PD-PRS among the 1851 factors, and of these, 27 factors showed causal evidence from MR analysis. Compelling evidence suggests that fluid intelligence score, age at first sexual intercourse, cereal intake, dried fruit intake, and average total household income before tax have emerged as newly identified risk factors for PD. Conversely, maternal smoking around birth, playing computer games, salt added to food, and time spent watching television have been identified as novel protective factors against PD. The integration of phenotypic and genomic data may help to identify risk factors and prevention targets for PD.

The distinct impacts of sarcopenic and dynapenic obesity on mortality in middle-aged and older adults based on different adiposity metrics: Results from I-Lan Longitudinal Aging Study

BACKGROUND & AIMS

Sarcopenic obesity (SO) and dynapenic obesity (DO) represent two manifestations of excessive fat accumulation concurrent with compromised muscle mass and function, thereby necessitating an examination of their implications for health. This study aims to investigate the relationship between SO/DO and mortality, taking into account various adiposity measures and existing sarcopenia criteria, with further stratified analyses based on age and gender.

METHODS

The study sample comprised 1779 older adults residing in the community from the I-Lan Longitudinal Aging Study (ILAS). Body composition was assessed via dual-energy X-ray absorptiometry. The diagnosis of sarcopenia was adhered to the 2019 consensus of the Asian Working Group for Sarcopenia, while adiposity was measured by waist circumference (WC), body mass index (BMI), and fat percentage. SO/DO was defined as the coexistence of sarcopenia/dynapenia and obesity. Multivariate Cox proportional hazard regression models were adopted to examine the association between SO or DO, defined by WC, BMI, fat percentage, and mortality.

RESULTS

This 11-year follow-up study of 1779 participants aged 63.9 ± 9.2 years involved 15,068 person-years and 229 deaths. WC-defined SO (HR 1.9, 95% CI 1.1-3.3, p = 0.021) and WC-defined DO (HR 1.4, 95% CI 1.1-1.9, p = 0.022) significantly increased mortality risk, whereas definitions employing alternative adiposity metrics exhibited no statistical significance. WC-defined SO was associated with increased risk of mortality among middle-aged adults, while WC-defined DO was associated with increased risk of mortality among older adults. In sex-specific analysis, WC-defined DO was also associated with increased risk of mortality in men (HR 1.6, 95% CI 1.1-2.4, p = 0.019), while defined by other measurements showed no associations in both sexes.

CONCLUSIONS

The study identified a significant link between SO/DO, defined by WC, and an 11-year mortality risk, advocating for WC-defined adiposity as an obesity measure and personalized interventions considering SO and DO's distinct impacts on mortality in middle-aged and older adults.

Obesity paradox of cardiovascular mortality in older adults in the United States: A cohort study using 1997-2018 National Health Interview Survey data linked with the National Death Index

BACKGROUND

Large-scale, population-based investigations primarily investigating the association between body mass index (BMI) and cardiovascular disease (CVD) mortality among older and younger adults in the United States (U.S.) are lacking.

OBJECTIVE

To evaluate the relationship between BMI and CVD mortality in older (≥65 years) and younger (<65 years) adults and to identify the nadir for CVD mortality.

DESIGN

This cohort study used serial cross-sectional data from the 1997 to 2018 National Health Interview Survey (NHIS) linked with the National Death Index. NHIS is an annual nationally representative household interview survey of the civilian noninstitutionalized U.S.

POPULATION

SETTING

Residential units of the civilian noninstitutionalized population in the U.S.

PARTICIPANTS

The target population for the NHIS is the civilian noninstitutionalized U.S. population at the time of the interview. We included all adults who had BMI data collected at 18 years and older and with mortality data being available. To minimize the risk of reverse causality, we excluded adults whose survival time was ≤2 years of follow-up after their initial BMI was recorded and those with prevalent cancer and/or CVD at baseline.

METHODS

We used the BMI record obtained in the year of the NHIS survey. Total CVD mortality used the NHIS data linked to the latest National Death Index data from the survey inception to December 31, 2019. We performed multivariable Cox proportional hazards regression models to estimate adjusted hazard ratios (aHRs) and 95 % confidence intervals (CIs).

RESULTS

The study included 425,394 adults; the mean (SD) age was 44 (16.7) years. During a median follow-up period of 11 years, 12,089 CVD-related deaths occurred. In older adults, having overweight was associated with a lower risk of CVD mortality (aHR 0.92 [95 % CI, 0.87-0.97]); having class I obesity (1.04 [0.97-1.12]) and class II obesity (1.12 [1.00-1.26]) was not significantly associated with an increased CVD mortality; and having class III obesity was associated with an increased risk of CVD mortality (1.63 [1.35-1.98]), in comparison with adults who had a normal BMI. Yet, in younger adults, having overweight, class I, II, and III obesity was associated with a progressively higher risk of CVD mortality. The nadir for CVD mortality is 28.2 kg/m2 in older adults and 23.6 kg/m2 in younger adults.

CONCLUSION

This U.S. population-based cohort study highlights the significance of considering age as a crucial factor when providing recommendations and delivering self-care educational initiatives for weight loss to reduce CVD mortality.

Associations between socioeconomic status and rates of blood pressure changes among Chinese older adults: a longitudinal community-based cohort study

OBJECTIVES

The relationships between socioeconomic status (SES) and blood pressure changes among older adults in China remain unclear. This study aimed to examine the associations between SES and rates of blood pressure changes among Chinese older adults.

STUDY DESIGN

Community-based, prospective, longitudinal cohort study.

METHODS

This study included 13,541 participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey between 2002 and 2018. SES was assessed by educational level, occupation, household yearly per capita income, and financial support. The estimated annual changes (EACs) of blood pressure were computed as the difference in blood pressure levels between any two adjacent surveys divided by the time interval. Associations between SES and EACs of blood pressure were evaluated using generalised estimating equations.

RESULTS

Lower SES was significantly associated with greater annual increases of blood pressure among Chinese older adults. The effect of SES on EACs of blood pressure was more pronounced among non-hypertensive participants. Compared to EACs among non-hypertensive participants with high SES, multivariable-adjusted EACs among those with low SES increased by 0.57 mmHg (95% confidence interval [CI]: 0.16, 0.99), 0.32 mmHg (95% CI: 0.07, 0.57), and 0.40 mmHg (95% CI: 0.13, 0.66) for systolic blood pressure, diastolic blood pressure, and mean arterial pressure, respectively.

CONCLUSIONS

This study revealed strong associations between SES and EACs of blood pressure among Chinese older adults, especially in the non-hypertensive population. Findings suggest that prevention strategies for hypertension should pay more attention to the older population with low SES.

Body mass index, waist circumference, and mortality in subjects older than 80 years: a Mendelian randomization study

BACKGROUND AND AIMS

Emerging evidence has raised an obesity paradox in observational studies of body mass index (BMI) and health among the oldest-old (aged ≥80 years), as an inverse relationship of BMI with mortality was reported. This study was to investigate the causal associations of BMI, waist circumference (WC), or both with mortality in the oldest-old people in China.

METHODS

A total of 5306 community-based oldest-old (mean age 90.6 years) were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998 and 2018. Genetic risk scores were constructed from 58 single-nucleotide polymorphisms (SNPs) associated with BMI and 49 SNPs associated with WC to subsequently derive causal estimates for Mendelian randomization (MR) models. One-sample linear MR along with non-linear MR analyses were performed to explore the associations of genetically predicted BMI, WC, and their joint effect with all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality.

RESULTS

During 24 337 person-years of follow-up, 3766 deaths were documented. In observational analyses, higher BMI and WC were both associated with decreased mortality risk [hazard ratio (HR) 0.963, 95% confidence interval (CI) 0.955-0.971 for a 1-kg/m2 increment of BMI and HR 0.971 (95% CI 0.950-0.993) for each 5 cm increase of WC]. Linear MR models indicated that each 1 kg/m2 increase in genetically predicted BMI was monotonically associated with a 4.5% decrease in all-cause mortality risk [HR 0.955 (95% CI 0.928-0.983)]. Non-linear curves showed the lowest mortality risk at the BMI of around 28.0 kg/m2, suggesting that optimal BMI for the oldest-old may be around overweight or mild obesity. Positive monotonic causal associations were observed between WC and all-cause mortality [HR 1.108 (95% CI 1.036-1.185) per 5 cm increase], CVD mortality [HR 1.193 (95% CI 1.064-1.337)], and non-CVD mortality [HR 1.110 (95% CI 1.016-1.212)]. The joint effect analyses indicated that the lowest risk was observed among those with higher BMI and lower WC.

CONCLUSIONS

Among the oldest-old, opposite causal associations of BMI and WC with mortality were observed, and a body figure with higher BMI and lower WC could substantially decrease the mortality risk. Guidelines for the weight management should be cautiously designed and implemented among the oldest-old people, considering distinct roles of BMI and WC.

Skeletal muscle mass increases after viral eradication with direct-acting antivirals in patients with chronic hepatitis C: A longitudinal study

BACKGROUND

Results of studies evaluating the effect of viral eradication following direct-acting antiviral (DDA) therapy on skeletal muscle mass of patients with chronic hepatitis C (CHC) are scarce.

AIM

To assess the components of sarcopenia (low muscle mass, low muscle strength and low physical performance) in a cohort of CHC individuals before and after DAA therapy.

METHODS

We performed a longitudinal study of patients with CHC who underwent body composition assessment before (T0), and at 12 (T1) and 48 (T2) weeks after DDA therapy. Bioelectrical Impedance Analysis was used to assess skeletal mass muscle (SM) and phase angle (PhA). SM index (SMI) was calculated by dividing the SM by squared height. Muscle function was evaluated by hand grip strength (HGS) and timed up-and-go (TUG) test. Mixed-effects linear regression models were fitted to SMI, HGS and physical performance and were used to test the effect of HCV eradication by DAA.

RESULTS

62 outpatients (mean age, 58.6 ± 10.8 years; 58% with compensated cirrhosis) were included. Significant decreases in liver fibrosis markers and an increase of 0.20 and 0.22 kg/m2 in the SMI were observed at T1 and T2. Following DAA therapy, an increase of one unit of PhA was associated with a reduction of 0.38 min in TUG.

CONCLUSION

HCV eradication with DAA therapy was associated with a dynamic reduction of non-invasive markers of liver fibrosis and increased muscle mass in 62 patients with CHC who had an undetectable HCV load at 12 weeks after completion of antiviral treatment.

Association of lifestyles and multimorbidity with mortality among individuals aged 60 years or older: Two prospective cohort studies

Lifestyles are associated with all-cause mortality, yet limited research has explored the association in the elderly population with multimorbidity. We aim to investigate the impact of adopting a healthy lifestyle on reducing the risk of all-cause mortality in older individuals with or without multimorbidity in both China and UK. This prospective study included 29,451 and 173,503 older adults aged 60 and over from Chinese Longitudinal Healthy Longevity Survey (CLHLS) and UK Biobank. Lifestyles and multimorbidity were categorized into three groups, respectively. Cox proportional hazards regression was used to estimate the Hazard Ratios (HRs), 95% confidence intervals (95% CIs), and dose-response for all-cause mortality in relation to lifestyles and multimorbidity, as well as the combination of both factors. During a mean follow-up period of 4.7 years in CLHLS and 12.14 years in UK Biobank, we observed 21,540 and 20,720 deaths, respectively. For participants with two or more conditions, compared to those with an unhealthy lifestyle, adopting a healthy lifestyle was associated with a 27%-41% and 22%-42% reduction in mortality risk in the CLHLS and UK Biobank, respectively; Similarly, for individuals without multimorbidity, this reduction ranged from 18% to 41%. Among participants with multimorbidity, individuals with an unhealthy lifestyle had a higher mortality risk compared to those maintaining a healthy lifestyle, with HRs of 1.15 (95% CI: 1.00, 1.32) and 1.27 (95% CI: 1.16, 1.39) for two conditions, and 1.24 (95% CI: 1.06, 1.45) and 1.73 (95% CI: 1.56, 1.91) for three or more conditions in CLHLS and UK Biobank, respectively. Adherence to a healthy lifestyle can yield comparable mortality benefits for older individuals, regardless of their multimorbidity status. Furthermore, maintaining a healthy lifestyle can alleviate the mortality risks linked to a higher number of diseases.

Development and validation of age-specific predictive equations for total energy expenditure and physical activity levels for older adults

BACKGROUND

Predicting energy requirements for older adults is compromised by the underpinning data being extrapolated from younger adults.

OBJECTIVES

To generate and validate new total energy expenditure (TEE) predictive equations specifically for older adults using readily available measures (age, weight, height) and to generate and test new physical activity level (PAL) values derived from 1) reference method of indirect calorimetry and 2) predictive equations in adults aged ≥65 y.

METHODS

TEE derived from "gold standard" methods from n = 1657 (n = 1019 females, age range 65-90 y), was used to generate PAL values. PAL ranged 1.28-2.05 for males and 1.26-2.06 for females. Physical activity (PA) coefficients were also estimated and categorized (inactive to very active) from population means. Nonlinear regression was used to develop prediction equations for estimating TEE. Double cross-validation in a randomized, sex-stratified, age-matched 50:50 split, and leave one out cross-validation were performed. Comparisons were made with existing equations.

RESULTS

Equations predicting TEE using the Institute of Medicine method are as follows: For males, TEE = -5680.17 - 17.50 × age (years) + PA coefficient × (6.96 × weight [kilograms] + 44.21 × height [centimeters]) + 1.13 × resting metabolic rate (RMR) (kilojoule/day). For females, TEE = -5290.72 - 8.38 × age (years) + PA coefficient × (9.77 × weight [kilograms] + 41.51 × height [centimeters]) + 1.05 × RMR (kilojoule/day), where PA coefficient values range from 1 (inactive) to 1.51 (highly active) in males and 1 to 1.44 in females respectively. Predictive performance for TEE from anthropometric variables and population mean PA was moderate with limits of agreement approximately ±30%. This improved to ±20% if PA was adjusted for activity category (inactive, low active, active, and very active). Where RMR was included as a predictor variable, the performance improved further to ±10% with a median absolute prediction error of approximately 4%.

CONCLUSIONS

These new TEE prediction equations require only simple anthropometric data and are accurate and reproducible at a group level while performing better than existing equations. Substantial individual variability in PAL in older adults is the major source of variation when applied at an individual level.

Association of anthropometric measures with all-cause and cause-specific mortality in US adults: revisiting the obesity paradox

OBJECTIVE

Previous studies have shown that the obesity paradox exists in a variety of clinical settings, whereby obese individuals have lower mortality than their normal-weight counterparts. It remains unclear whether the association between obesity and mortality risk varies by anthropometric measures. The purpose of this study is to examine the association between various anthropometric measures and all-cause and cause-specific mortality in US adults.

METHODS

This cohort study included data from the National Health and Nutrition Examination Survey between 2009 and 2018, with a sample size of 28,353 individuals weighted to represent 231 million US adults. Anthropometric measurements were obtained by trained technicians using standardized methods. Mortality data were collected from the date of enrollment through December 31, 2019. Weighted Cox proportional hazards models, restricted cubic spline curves, and cumulative incidence analyses were performed.

RESULTS

A total of 2091 all-cause deaths, 606 cardiovascular deaths, 519 cancer deaths, and 966 other-cause deaths occurred during a median follow-up of 5.9 years. The association between body mass index (BMI) and mortality risk was inversely J-shaped, whereas the association between waist-to-height ratio (WHtR) and mortality risk was positively J-shaped. There was a progressive increase in the association between the WHtR category and mortality risk. Compared with the reference category of WHtR < 0.5, the estimated hazard ratio (HR) for all-cause mortality was 1.004 (95% confidence interval [CI] 1.001-1.006) for WHtR 0.50-0.59, 1.123 (95% CI 1.120-1.127) for WHtR 0.60-0.69, 1.591 (95% CI 1.584-1.598) for WHtR 0.70-0.79, and 2.214 (95% CI 2.200-2.228) for WHtR ≥ 0.8, respectively. Other anthropometric indices reflecting central obesity also showed that greater adiposity was associated with higher mortality.

CONCLUSIONS

Anthropometric measures reflecting central obesity were independently and positively associated with mortality risk, eliminating the possibility of an obesity paradox.

The development and validation of a nomogram-based risk prediction model for mortality among older adults

Objective

This research aims to construct and authenticate a comprehensive predictive model for all-cause mortality, based on a multifaceted array of risk factors.

Methods

The derivation cohort for this study was the Chinese Longitudinal Healthy Longevity Survey (CLHLS), while the Healthy Ageing and Biomarkers Cohort Study (HABCS) and the China Health and Retirement Longitudinal Study (CHARLS) were used as validation cohorts. Risk factors were filtered using lasso regression, and predictive factors were determined using net reclassification improvement. Cox proportional hazards models were employed to establish the mortality risk prediction equations, and the model's fit was evaluated using a discrimination concordance index (C-index). To evaluate the internal consistency of discrimination and calibration, a 10x10 cross-validation technique was employed. Calibration plots were generated to compare predicted probabilities with observed probabilities. The prediction ability of the equations was demonstrated using nomogram.

Results

The CLHLS (mean age 88.08, n = 37074) recorded 28158 deaths (179683 person-years) throughout the course of an 8-20 year follow-up period. Additionally, there were 1384 deaths in the HABCS (mean age 86.74, n = 2552), and 1221 deaths in the CHARLS (mean age 72.48, n = 4794). The final all-cause mortality model incorporated demographic characteristics like age, sex, and current marital status, as well as functional status indicators including cognitive function and activities of daily living. Additionally, lifestyle factors like past smoking condition and leisure activities including housework, television viewing or radio listening, and gardening work were included. The C-index for the derivation cohort was 0.728 (95% CI: 0.724-0.732), while the external validation results for the CHARS and HABCS cohorts were 0.761 (95% CI: 0.749-0.773) and 0.713 (95% CI: 0.697-0.729), respectively.

Conclusion

This study introduces a reliable, validated, and acceptable mortality risk predictor for older adults in China. These predictive factors have potential applications in public health policy and clinical practice.

Impact of obesity on intensive care unit outcomes in older patients with critical illness: A cohort study

BACKGROUND

Although the paradoxical association between obesity and improved survival has been reported in a variety of clinical settings, its applicability to intensive care unit (ICU) outcomes in older critically ill patients remains unclear. We sought to examine the association between obesity and 30-day mortality and other adverse outcomes in this population.

METHODS

We analyzed data of older patients (≥ 60 years) in the eICU Collaborative Research Database. Body mass index (BMI) was stratified according to the World Health Organization obesity classification. Logistic regression model was used to estimate adjusted odds ratios (ORs), and cubic spline curve was used to explore the nonlinear association between BMI and 30-day ICU outcomes. Stratified analysis and sensitivity analysis were also performed.

RESULTS

Compared with class I obesity, under- and normal-weight were associated with higher all-cause, cardiovascular and noncardiovascular mortality, and class III obesity was associated with greater all-cause and cardiovascular mortality (OR, 1.18 [95% CI, 1.06-1.32], 1.28 [1.08-1.51]). Obesity classes II and III were associated with higher composite all-cause mortality, mechanical ventilation, or vasoactive drug usage risks (OR, 1.12 [95% CI, 1.04-1.20], 1.33 [1.24-1.43]). Mechanical ventilation was strongly positively associated with BMI. A significant BMI-by-sex interaction was observed for cardiovascular mortality, such that the association between severe obesity and mortality was more pronounced among older men than older women.

CONCLUSIONS

The obesity paradox does not appear to apply to short-term ICU outcomes in older patients with critical illness, mainly due to increased all-cause and cardiovascular mortality in severely obese patients, particularly in men.

Association of systemic inflammation with the obesity paradox in cancer: results from multi-cohort studies

AIMS

This study aimed to explore whether the obesity paradox exists in overall and specific cancers and to investigate the role of systemic inflammation in the obesity paradox.

METHODS

The Cox proportional hazard model was used to explore the relationship between body mass index (BMI) and all-cause mortality. The mediated effect was used to investigate the proportion of systemic inflammation mediating the relationship between BMI and cancer survival risk.

RESULTS

The survival probability showed a step-like increase with an increase in BMI regardless of pathological stage. Approximately 10.8%-24.0% of the overall association between BMI and all-cause mortality in cancer was mediated by inflammation. In the internal validation, we found evidence of the obesity paradox in all body composition obtained using BIA, with inflammation remaining an important mediating factor. Furthermore, we also validated the existence of the obesity paradox of cancer in NHANES. Systemic inflammation remains an important factor in mediating the association between BMI and prognosis in cancer patients.

CONCLUSIONS

The obesity paradox is prevalent in most cancers, except for hepatic biliary cancer and breast cancer. Inflammation may be one of the true features of the obesity paradox in cancer.

Frailty modifies the association of body mass index with mortality among older adults: Kyoto-Kameoka study

BACKGROUND & AIMS

The differences in the association of body mass index (BMI) with mortality between older adults with and without frailty remain unclear. This study investigated this association in community-dwelling older adults with and without frailty.

METHODS

This prospective study included 10,912 adults aged ≥65 years who provided valid responses to a baseline mail survey questionnaire in the Kyoto-Kameoka Study in Japan. The BMI was calculated based on self-reported height and body weight and classified into four categories: <18.5, 18.5-21.4, 21.5-24.9, and ≥25.0 kg/m2. Frailty was evaluated using the validated Kihon Checklist and defined as a score of 7 or higher out of a possible 25 points. Mortality data were collected from 30 July 2011 to 30 November 2016. Hazard ratios (HR) for all-cause mortality were calculated using a multivariable Cox proportional hazards model.

RESULTS

During the 5.3 year median follow-up period (54,084 person-years), 1352 deaths were recorded. After adjusting for confounders, including lifestyle and medical history, compared with participants with a BMI of 21.5-24.9 kg/m2, those in the lower BMI category had a higher mortality HR, while those with a higher BMI displayed an inverse association with mortality (<18.5 kg/m2: HR: 1.85, 95% confidence interval [CI]: 1.58-2.17; 18.5-21.4 kg/m2: HR: 1.38, 95% CI: 1.21-1.58; and ≥25.0 kg/m2: HR: 0.80, 95% CI: 0.67-0.96). In a model stratified by frailty status, the BMI range with the lowest HR for mortality was 23.0-24.0 kg/m2 in non-frail older adults; however, in frail older adults, a higher BMI was inversely associated with mortality.

CONCLUSIONS

The relationship between BMI and mortality varies between individuals with and without frailty, with those experiencing frailty potentially benefiting from a higher BMI compared to those without frailty. This study suggests that frailty should be assessed when considering the optimal BMI for the lowest mortality risk among older adults.

Influencing Factors on Cardiovascular Health in China

The Annual Report on Cardiovascular Health and Diseases in China (2022) intricate landscape of cardiovascular health in China. This is the first section of the report, which dissects influential factors across diverse domains. The investigation identifies tobacco use as a paramount concern, portraying China as the global epicenter of tobacco consumption. Cigarette smoking, exacerbated by second-hand smoke exposure, emerges as a critical and preventable risk factor, contributing to a surge in attributable deaths over the past three decades. In the realm of dietary nutrition, the study discerns an overall improvement, yet discerns worrisome deviations, notably an escalating fat intake surpassing recommended guidelines. The shifting dietary structure reveals diminished consumption of cereals and vegetables juxtaposed with an uptick in animal foods, while excessive intake of cooking oil and salt persists, straying substantially from endorsed levels. The exploration of physical activity patterns unfolds a nuanced narrative. Varied trends are observed among students, with concerns arising from sedentary behaviors and inadequate adherence to recommended guidelines. The analysis spans a trajectory of declining physical activity in Chinese adults, coupled with an alarming surge in sedentary leisure time, ultimately linking these factors to heightened risks of cardiovascular diseases and increased adiposity. An examination of overweight and obesity trends uncovers a relentless upward trajectory, projecting substantial prevalence by 2030. Noteworthy prevalence rates underscore the imperative for targeted interventions to curtail this burgeoning health crisis, with the anticipated prevalence extending to nearly two-thirds of the adult population. Psychological factors, notably depression, constitute an integral facet of cardiovascular health. Prevalence rates among patients with coronary artery disease and acute myocardial infarction underscore the intricate interplay between mental health and cardiovascular outcomes. Additionally, persistent depressive symptoms are shown to significantly elevate the risk of cardiovascular diseases and mortality. This first section underscores the multifaceted challenges facing cardiovascular health in China, emphasizing the imperative for tailored interventions across tobacco control, dietary habits, physical activity, obesity management, and psychological well-being to mitigate the escalating burden of cardiovascular diseases in the population.

COVID-19-related cardiovascular disease risk due to weight gain: a nationwide cohort study

BACKGROUND

Cardiovascular disease (CVD) is a significant contributor to morbidity and mortality worldwide, with CVD and post-acute COVID-19 associated CVD increasing. It remains unknown whether COVID-19 patients with weight gain are at a high risk for CVD events. Therefore, the primary objective of this study is to investigate the association between weight control and the risk of CVD following COVID-19.

METHODS

The study included 2,024,728 adults who participated in two rounds of health screening between 2017 and 2020. The final cohort, which included 70,996 participants in the COVID-19 group and 212,869 participants in the control group. The adjusted hazard ratio of BMI change to CVD risk was calculated using Cox proportional hazards regression.

RESULTS

We identified a total of 2869 cases of CVD (861 events for COVID-19 group and 2,008 events for the control group). Compared to individuals with a stable BMI, COVID-19 patients without obesity had an increased risk of CVD (adjusted hazard ratio [aHR] = 2.28; 95% confidence interval [CI], 1.15-4.53; p-value = 0.018). Additionally, non-COVID-19 patients with obesity also exhibited a higher risk of CVD (aHR = 1.58; 95% CI, 1.01-2.47; p-value = 0.046).

CONCLUSION

In conclusion, people who gained weight during the pandemic, regardless of their weight category, had a significantly higher risk of CVD associated with COVID-19 compared to those who maintained their weight before the pandemic.

Disparities in overall survival by varying duration of disability in activities of daily living in older people: A population-based cohort from Chinese Longitudinal Healthy Longevity Survey (CLHLS)

OBJECTIVES

To investigate the association between duration of disability in activity of daily living (ADL) and overall survival in older individuals.

DESIGN

A prospective cohort study.

SETTING

Community-based data from Chinese Longitudinal Healthy Longevity Survey.

PARTICIPANTS

In total, 13,560 participants without ADL disability and 2772 participants with ADL disability at baseline were included.

MEASUREMENTS

ADL disability was assessed using Katz index scale, which included six essential ADLs: dressing, bathing, transferring, toileting, continence, and eating. Dependence of each item was scored on a scale of 1, the maximum total score was 6. At baseline, duration of ADL disability was defined as the maximum duration among the six items. The study outcome was overall survival. Accelerated failure time models were constructed to investigate the association between duration of ADL disability and overall survival. Subgroup analyses by sex, age, and multimorbidites, as well as sensitive analyses were conducted.

RESULTS

During 81,868.7 person-years follow-up, 11,092 deaths were recorded. Overall, ADL disability was associated with lower overall survival compared to non-ADL disability. With duration of ADL disability extending, the overall survival strikingly dropped in the first 12 months, reaching its lowest point with adjusted time ratio (TR) at 0.66 (95%CI: 0.61-0.72, p < 0.001), then moderately grew until the 60th month, finally stayed constant thereafter. Participants with ADL scores of 1-3 had higher survival compared to those with scores of 4-6, and both groups followed a similar trend of varied survival to the whole cohort. Moreover, subgroup analyses and sensitivity analyses showed the robustness of these findings.

CONCLUSIONS

Our findings first address a golden time window for the older individuals with ADL disability. More attention should be given to them, especially in the first 12 months since diagnosis, to reduce mortality and extend the lifespan.

Associations Between Mid- to Late-Life Body Mass Index and Chronic Disease-Free Survival: A Nationwide Twin Study

BACKGROUND

Some studies have linked late-life overweight to a reduced mortality risk compared to normal body mass index (BMI). However, the impact of late-life overweight and its combination with mid-life BMI status on healthy survival remains unclear. We aimed to investigate whether and to what extent mid- and/or late-life overweight are associated with chronic disease-free survival.

METHODS

Within the Swedish Twin Registry, 11 597 chronic disease-free twins aged 60-79 years at baseline were followed up for 18 years. BMI (kg/m2) was recorded at baseline and 25-35 years before baseline (ie, midlife) and divided as underweight (<20), normal (≥20-25), overweight (≥25-30), and obese (≥30). Incident chronic diseases (cardiovascular diseases, type 2 diabetes, and cancer) and deaths were ascertained via registries. Chronic disease-free survival was defined as years lived until the occurrence of any chronic diseases or death. Data were analyzed using multistate survival analysis.

RESULTS

Of all participants, 5 640 (48.6%) were overweight/obese at baseline. During the follow-up, 8 772 (75.6%) participants developed at least 1 chronic disease or died. Compared to normal BMI, late-life overweight and obesity were associated with 1.1 (95% CI, 0.3, 2.0) and 2.6 (1.6, 3.5) years shorter chronic disease-free survival. Compared to normal BMI through mid- to late life, consistent overweight/obesity and overweight/obesity only in mid-life led to 2.2 (1.0, 3.4) and 2.6 (0.7, 4.4) years shorter disease-free survival, respectively.

CONCLUSIONS

Late-life overweight and obesity may shorten disease-free survival. Further research is needed to determine whether preventing overweight/obesity from mid- to late life might favor longer and healthier survival.

Individualized threshold of the involuntary weight loss in prognostic assessment of cancer

BACKGROUND

Involuntary weight loss (WL) is a common symptom in cancer patients and is associated with poor outcomes. However, there is no standardized definition of WL, and it is unclear what magnitude of weight loss should be considered significant for prognostic purposes. This study aimed to determine an individualized threshold for WL that can be used for prognostic assessment in cancer patients.

METHODS

Univariate and multivariate analyses of overall survival (OS) were performed using Cox proportional hazard models. The Kaplan-Meier method was performed to estimate the survival distribution of different WL levels. Logistic regression analysis was used to determine the relationship between WL and 90-day outcomes. Restricted cubic splines with three knots were used to examine the effects of WL on survival under different body mass index (BMI) conditions.

RESULTS

Among the 8806 enrolled patients with cancer, median survival time declined as WL increased, from 25.1 to 20.1, 17.8 and 16.4 months at <2%, 2-5%, 5-10% and ≥10% WL, respectively (P < 0.001). Multivariate adjusted Cox regression analysis showed that the risk of adverse prognosis increased by 18.1% based on the SD of WL (5.45 U) (HR: 1.181, 95% CI: 1.144-1.219, P < 0.001). Similarly, categorical WL was independently associated with OS in patients with cancer. With the worsening of WL, the risk of a poor prognosis in patients increases stepwise. Compared with <2% WL, all-cause mortalities were 15.1%, 37% and 64.2% higher in 2-5%, 5-10%, and ≥10% WL, respectively. WL can effectively stratify the prognosis of both overall and site-specific cancers. The clinical prognostic thresholds for WL based on different BMI levels were 4.21% (underweight), 5.03% (normal), 6.33% (overweight), and 7.60% (obese). Multivariate logistic regression analysis showed that WL was independently associated with 90-day outcomes in patients with cancer. Compared with patients with <2% WL, those with ≥10% WL had more than twice the risk of 90-day outcomes (OR: 3.277, 95% CI: 2.287-4.694, P < 0.001). Systemic inflammation was a cause of WL deterioration. WL mediates 6.3-10.3% of the overall association between systemic inflammation and poor prognoses in patients with cancer.

CONCLUSIONS

An individualized threshold for WL based on baseline BMI can be used for prognostic assessment in cancer patients. WL and BMI should be evaluated simultaneously in treatment decision-making, nutritional intervention, and prognosis discussions of patients with cancer.

Healthy lifestyle in late-life, longevity genes, and life expectancy among older adults: a 20-year, population-based, prospective cohort study

BACKGROUND

Lifestyle and longevity genes have different and important roles in the human lifespan; however, the association between a healthy lifestyle in late-life and life expectancy mediated by genetic risk is yet to be elucidated. We aimed to investigate the associations of healthy lifestyle in late-life and genetic risk with life expectancy among older adults.

METHODS

A weighted healthy lifestyle score was constructed from the following variables: current non-smoking, non-harmful alcohol consumption, regular physical activity, and a healthy diet. Participants were recruited from the Chinese Longitudinal Healthy Longevity Survey, a prospective community-based cohort study that took place between 1998 and 2018. Eligible participants were aged 65 years and older with available information on lifestyle factors at baseline, and then were categorised into unhealthy (bottom tertile of the weighted healthy lifestyle score), intermediate (middle tertile), and healthy (top tertile) lifestyle groups. A genetic risk score was constructed based on 11 lifespan loci among 9633 participants, divided by the median and classified into low and high genetic risk groups. Stratified Cox proportional hazard regression was used to estimate the interaction between genetic and lifestyle factors on all-cause mortality risk.

FINDINGS

Between Jan 13, 1998, and Dec 31, 2018, 36 164 adults aged 65 years and older were recruited, among whom a total of 27 462 deaths were documented during a median follow-up of 3·12 years (IQR 1·62-5·94) and included in the lifestyle association analysis. Compared with the unhealthy lifestyle category, participants in the healthy lifestyle group had a lower all-cause mortality risk (hazard ratio [HR] 0·56 [95% CI 0·54-0·57]; p<0·0001). The highest mortality risk was observed in individuals in the high genetic risk and unhealthy lifestyle group (HR 1·80 [95% CI 1·63-1·98]; p<0·0001). The absolute risk reduction was greater for participants in the high genetic risk group. A healthy lifestyle was associated with a gain of 3·84 years (95% CI 3·05-4·64) at the age of 65 years in the low genetic risk group, and 4·35 years (3·70-5·06) in the high genetic risk group.

INTERPRETATION

A healthy lifestyle, even in late-life, was associated with lower mortality risk and longer life expectancy among Chinese older adults, highlighting the importance of a healthy lifestyle in extending the lifespan, especially for individuals with high genetic risk.

FUNDING

National Natural Science Foundation of China.

TRANSLATION

For the Mandarin translation of the abstract see Supplementary Materials section.

Subcutaneous adipose tissue alteration in aging process associated with thyroid hormone signaling

BACKGROUND

Functional changes in subcutaneous adipose tissue (SAT) occur earlier in the aging process and play an important role in the occurrence and development of age-related metabolic diseases. The mechanism of this phenomenon is still unclear, and the change in adipose tissue with age is poorly understood.

METHODS

We used transcriptome sequencing (RNA seq) to screen differentially expressed genes at the mRNA level, and analyzed the functional characteristics of the differential genes through GO and KEGG analysis in human SAT of all ages. In order to clarify the specific mechanism of the functional change, we analyzed the chromatin accessibility in the promoter region in the same SAT used in the RNA seq by the assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) and obtained the functional genes in SAT changed with age. To verify these changes, we enlarged our sample content of human SAT. The primary mice adipocytes were extracted and stimulated by thyroid hormone of different concentration to construct an animal model, and the expression of the genes were determined through real-time Polymerase Chain Reaction(RT-PCR). The oxygen consumption test and immunofluorescence staining were used to determine the mitochondrial function of SAT.

RESULTS

RNA-seq showed characteristic gene expression of young and old human SAT, in which 331 genes were up-regulated and 349 genes were down-regulated. ATAC-seq, RNA-seq, combined with the mouse prediction model, determined the functional changed characteristics of seven genes. All these genes expressed differently in SAT of different ages, in which, NCF1, NLRP3, DUOX1 showed positive correlation with age; The expression of IFI30, P2RX1, P2RX6, PRODH, however, decreased with age. And all these genes showed dose dependent alternations under treatment of triiodothyroxine in mice SAT. The oxygen consumption rate revealed significant changes of the mitochondrial function and ROS accumulation in human SAT of different ages.

CONCLUSION

In elderly individuals, the function, in addition to distribution, of SAT undergoes significant changes, primarily in mitochondria, which may be due to insensitivity to thyroid hormone signaling. These results identified seven novel genes regulated by thyroid hormone, exhibiting significant changes in SAT of different age, and are probably related to the dysfunction of the aged SAT due to the mitochondrial damage and ROS accumulation.

Advanced liver fibrosis predicts heart failure and hospitalizations in people with type 2 diabetes: A prospective cohort study from Hong Kong Diabetes Register

AIMS

We aimed to examine the impact of non-alcoholic fatty liver disease (NAFLD) on the clinical outcomes in patients with type 2 diabetes (T2D).

METHODS

Between 2013 and 2014, 1,734 patients with T2D underwent transient elastography (TE) to assess liver status indicated by controlled attenuation parameter (CAP) and liver stiffness measurement (LSM). Liver steatosis was defined by CAP ≥248 dB/m and advanced liver fibrosis by LSM ≥10kPa. In 2019, we assessed their clinical outcomes including hospitalizations and mortality.

RESULTS

In this prospective cohort [56% men, mean (±standard deviation) age:60.8±11.5 years; glycated hemoglobin (HbA_1c)7.8±1.6 %], 798 patients had liver steatosis, 296 patients had advanced liver fibrosis and 640 patients had normal liver at baseline. T2D with advanced liver fibrosis had higher body mass index, waist circumference, waist-hip ratio, fasting plasma glucose, HbA_1c, blood pressure and lipid profiles than their counterparts with NAFLD or normal liver (all p<0.05). After a median follow-up of 6.07 (interquartile range:5.84 to 6.30) years, there were 4,403 incident hospitalizations, 32,119 days of hospital stay, and 171 deaths. Using Cox regression analysis, advanced liver fibrosis was associated with increased risk of heart failure (hazard ratio [95% confidence interval] HR:3.07[1.08-8.68], p=0.035) and hospitalizations (HR: 1.39[1.14 -1.70], p=0.001) while liver steatosis was associated with reduced mortality (HR:0.60[0.41-0.87], p=0.007) compared to their counterparts with normal liver after adjustment for potential confounders.

CONCLUSIONS

T2D comorbid with liver steatosis and advanced liver fibrosis are distinct clinical entities with differences in outcomes. Advanced liver fibrosis is an important predictor for worse outcomes including heart failure and hospitalizations in people with T2D.

Sarcopenic obesity: epidemiology, pathophysiology, cardiovascular disease, mortality, and management

Sarcopenic obesity is defined as the coexistence of sarcopenia and obesity in the same individual, characterized by of the co-presence of body fat accumulation and muscle loss. This condition is currently a major concern as it is associated with frailty and disabilities such as cardiovascular disease, fractures, dementia, cancer, and increased all-cause mortality. Particularly, older individuals remain at risk of sarcopenic obesity. Progress at several levels is needed to improve the global prognostic outlook for this condition, including the elaboration and implementation of a more uniform definition that may favor the identification and specification of prevalence by age group. Furthermore, improvements in the understanding of the pathogenesis of sarcopenic obesity may lead to the development of more specific therapeutic interventions to improve prognosis. We reviewed the knowledge on sarcopenic obesity and its associations with cardiovascular diseases and mortality.

A Body Shape Index and Its Changes in Relation to All-Cause Mortality among the Chinese Elderly: A Retrospective Cohort Study

Although recent evidence has revealed that a body shape index (ABSI) is correlated with the incidence of death among different ethnicities, there remains a paucity of studies investigating the impact of ABSI on mortality within the Chinese elderly. Our objective was to ascertain the link between ABSI, as well as its alterations over time, and all-cause mortality among Chinese aged 65 y and above. A total of 3789 participants were enrolled from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Cox regressions and restricted cubic splines were employed to assess the association of ABSI and relative changes with all-cause mortality. When nonlinearity was detected, a restricted cubic spline regression was subsequently conducted to compute hazard ratios and 95% confidence intervals. The median survival time was 46 months, and 1342 individuals (35.4%) were reported to have died. ABSI contributed independently to rising death rates among Chinese old populations according to univariate and multivariate Cox regressions. Statistically significant associations were also found stratified by age, sex, and lifestyle. A U-shaped association of ABSI changes with all-cause mortality (p = 0.027) was observed, indicating that old adults with stable ABSI during the follow-up period experienced the lowest risk of mortality. After multivariable adjustment, participants with a 10% reduction in ABSI changes had an increased 9.4% risk of death, while participants with a 10% rise in ABSI changes had an increased 1.9% risk. ABSI and its changes are predictors for all-cause mortality among the elderly Chinese population, which emphasizes the clinical importance of monitoring ABSI and keeping it stable over time.

Associations of non-traditional cardiovascular risk factors and body mass index with metabolic syndrome in the Chinese elderly population

BACKGROUND

Metabolic syndrome (MetS), a clustering of traditional cardiovascular risk factors (CVRF), is currently one of the major global public health burdens. However, associations between MetS and non-traditional CVRF represented by uric acid (UA), homocysteine (HCY) and hypersensitive C-reactive protein (HsCRP) have not been well explored in the elderly population, especially when considering body mass index (BMI).

METHODS

Participants from the Shanghai Elderly Cardiovascular Health (SHECH) study cohort in 2017 were analyzed. MetS was defined using the modified American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Logistic regression models were used to assess associations of non-traditional CVRF, BMI with MetS.

RESULTS

Of the 4360 participants analyzed, 2378 (54.5%) had MetS, the mean (SD) UA was 331 (86) µmol/L, and the median (IQR) HCY and HsCRP were 15 (13-18) µmol/L and 1.0 (0.5-2.1) mg/L, respectively. Participants with higher non-traditional CVRF tended to have a higher significant risk of MetS (P < 0.001), which did not changed substantially in most population subgroups (P-interaction > 0.05). BMI mediated 43.89% (95%CI: 30.38-57.40%), 37.34% (95% CI: 13.86-60.83%) and 30.99% (95%CI: 13.16-48.83%) of associations of hyperuricemia (HUA), hyperhomocysteinemia (HHCY) and high HsCRP (HHsCRP) with MetS, respectively. Abnormal non-traditional CVRF combined with overweight/obesity greatly increased MetS risk (adjusted OR(95%CI): HUA + Overweight: 5.860(4.059-8.461); 6.148(3.707-10.194); HHCY + Overweight: 3.989(3.107-5.121); HHCY + Obese: 5.746(4.064-8.123); HHsCRP + Overweight: 4.026(2.906-5.580); HHsCRP + Obese: 7.717(4.508-13.210)).

CONCLUSIONS

In the Chinese elderly population, HUA, HHCY, and HHsCRP were all significantly and independently associated with MetS, supporting the potential of focusing on non-traditional CVRF interventions for preventing and controlling MetS. BMI played moderate mediating roles in associations between non-traditional CVRF and MetS, and abnormal non-traditional CVRF combined with overweight/obesity had significant synergistic effects on MetS risk, highlighting the importance of better weight management in the elderly population.

Promotion of Healthy Lifestyles Alone Might Not Substantially Reduce Socioeconomic Inequity-Related Mortality Risk in Older People in China: A Prospective Cohort Study

BACKGROUND

Whether healthy lifestyles mediate the association of socioeconomic status (SES) with mortality in older people is largely unknown.

METHODS

A total of 22,093 older participants (age ≥ 65 years) from 5 waves (2002-2014) of Chinese Longitudinal Healthy Longevity Survey cohort were included for analysis. Mediation analysis of lifestyles on the association of SES with all-cause mortality was conducted.

RESULTS

During a mean follow-up period of 4.92 ± 4.03 years, 15,721 (71.76%) deaths occurred. Compared with high SES, medium SES increased the risk of mortality by 13.5% (HR [total effect]: 1.135, 95% CI 1.067-1.205, p < 0.001), and the total effect was not mediated by healthy lifestyles (mediation proportion: - 0.1%, 95% CI - 3.8 to 3.3%, p = 0.936). The total effect when participants of low SES were compared with participants of high SES was HR = 1.161 (95% CI 1.088-1.229, p < 0.001) for mortality, and the total effect was modestly mediated through healthy lifestyles (mediation proportion: - 8.9%, 95% CI - 16.6 to - 5.1%, p < 0.001). Stratification analyses by sex, age and comorbidities, as well as a series of sensitivity analyses indicated similar results. In addition, mortality risk showed a downward trend with increased number of healthy lifestyles within each SES level (all p for trend < 0.050).

CONCLUSION

Promotion of healthy lifestyles alone can only reduce a small proportion of socioeconomic inequity-related mortality risk in older Chinese people. Even so, healthy lifestyles are important in reducing the overall mortality risk within each SES level.

The influence of vitamin D supplementation and strength training on health biomarkers and chromosomal damage in community-dwelling older adults

Older adults lack of proper physical activity which is often accompanied by vitamin D deficiency. Those factors are known to contribute to health issues in the later years of life. The main goal of this intervention study was to investigate the effect of different vitamin D supplementation strategies for 4 weeks solely or combined with a 10-week strength training program on chromosomal stability in peripheral blood mononuclear cells in community-dwelling older people. One hundred women and men (65-85 years) received either vitamin D3 daily (800 IU), a monthly dose (50.000 IU) or placebo for 17 weeks. All groups received 400 mg calcium daily. The fitness status of the study participants was measured using the 30- second chair stand test, the handgrip strength test and the 6-min walk test. The cytokinesis block micronucleus cytome (CBMN) assay was applied to analyze chromosomal anomalies, including cytotoxic and genotoxic parameters. Changes in antioxidant markers were measured in plasma. Walking distance and chair stand performance improved significantly. Increased levels of the parameters of the CBMN assay were detected for all intervention groups at study end. At baseline micronuclei (MNi) frequency correlated significantly with BMI in both sexes (females: r = 0.369, p = 0.034; males: r = 0.265, p = 0.035), but not with vitamin D serum levels. In females, body fat (r = 0.372, p < 0.001) and functional parameter using the 30-s chair stand test (r = 0.311, p = 0.002) correlated significantly with MNi frequency. Interestingly, not vitamin D supplementation but 10 weeks of resistance training increased MNi frequency indicating elevated chromosomal instability and also adverse effects on antioxidant markers including glutathione and FRAP were detected in the group of community-dwelling older adults.

Leisure Activities, Genetic Risk, and Frailty: Evidence from the Chinese Adults Aged 80 Years or Older

INTRODUCTION

About half of adults aged ≥80 years suffer from frailty. Exercise is considered effective in preventing frailty but may be inapplicable to adults aged ≥80 years due to physical limitations. As an alternative, we aimed to explore the association of leisure activities with frailty and identify potential interaction with established polygenic risk score (PRS) among adults aged ≥80 years.

METHODS

Analyses were performed in a prospective cohort study of 7,471 community-living older adults aged ≥80 years who were recruited between 2002 and 2014 from 23 provinces in China. Leisure activity was assessed using a seven-question leisure activity index and frailty was defined as a frailty index ≥0.25 using a validated 39-item health-related scale. The PRS was constructed using 59 single-nucleotide polymorphisms associated with frailty in a subsample of 2,541 older adults. Cox proportional hazards models were used to explore the associations of leisure activities, PRS with frailty.

RESULTS

The mean age of participants was 89.4 ± 6.6 years (range: 80-116). In total, 2,930 cases of frailty were identified during 42,216 person-years of follow-up. Each 1 unit increase in the leisure activity index was associated with 12% lower risk of frailty (hazard ratio: 0.88 [95% confidence interval, 0.85-0.91]). Participants with high genetic risk (PRS >2.47 × 10-4) suffered from 26% higher risk of frailty. Interaction between leisure activity and genetic risk was not observed.

CONCLUSION

Evidence is presented for the independent association of leisure activities and genetic risk with frailty. Engagement in leisure activities is suggested to be associated with lower risk of frailty across all levels of genetic risk among adults aged ≥80 years.

Body mass index and death by cognitive impairment

BACKGROUND

Epidemiological studies have reported that among participants with impaired cognitive, overweight and mild obesity are associated with substantially improved survival, this finding has been termed the "obesity paradox" and has led to uncertainty about secondary prevention.

AIMS

To explore whether the association of BMI with mortality differed in different MMSE score, and whether the obesity paradox in patient with cognitive impairment (CI) is real.

METHODS

The study used data from CLHLS, a representative prospective population-based cohort study in China, which included 8348 participants aged ≥ 60 years between 2011 and 2018. The independent association between BMI and mortality in differed MMSE score by calculating hazard ratios (HRs) in multivariate Cox regression analysis.

RESULTS

During a median (IQR) follow-up of 41.18 months, a total of 4216 participants died. In the total population, underweight increased the risk of all-cause mortality (HRs, 1.33; 95% CI 1.23-1.44), compared with normal weight, and overweight was associated with a decreased risk of all-cause mortality (HR 0.83; 95% CI 0.74-0.93). However,  compared to normal weight, only underweight was associated with increased mortality risk among participants with MMSE scores of 0-23, 24-26, 27-29, and 30, and the fully-adjusted HRs (95% CIs) for mortality were 1.30 (1.18, 1.43), 1.31 (1.07, 1.59), 1.55 (1.34, 1.80) and 1.66 (1.26, 2.20), respectively. The obesity paradox was not found in individuals with CI. Sensitivity analyses carried out had hardly any impact on this result.

CONCLUSION

We found no evidence of an obesity paradox in patients with CI, compared with patients of normal weight. But underweight individuals may have increased mortality risk whether in the population with CI or not. And overweight/obese people with CI should continue to aim for normal weight.

The role of obesity in sarcopenia and the optimal body composition to prevent against sarcopenia and obesity

Background

Elderly people with low lean and high fat mass, are diagnosed with sarcopenic obesity (SO), and often have poor clinical outcomes. This study aimed to explore the relationship between obesity and sarcopenia, and the optimal proportion of fat and muscle for old individuals.

Methods

Participants aged 60 years or above were instructed to perform bioelectrical impedance analysis to obtain the muscle and fat indicators, and handgrip strength was also performed. Sarcopenia was diagnosed according to predicted appendicular skeletal muscle mass and function. Body mass index (BMI) and body fat percentage (BF%) were used to define obesity. The association of muscle and fat indicators were analyzed by Pearson's correlation coefficient. Pearson Chi-Square test was utilized to estimate odds ratios (OR) and 95% confidence intervals (CI) on the risk of sarcopenia according to obesity status.

Results

1637 old subjects (74.8 ± 7.8 years) participated in this study. Not only fat mass, but also muscle indicators were positively correlated to BMI and body weight (p < 0.05). Absolute muscle and fat mass in different positions had positive associations (p < 0.05). Muscle mass and strength were negatively related to appendicular fat mass percentage (p < 0.05). When defined by BMI (OR = 0.69, 95% CI [0.56, 0.86]; p = 0.001), obesity was a protective factor for sarcopenia, whilst it was a risk factor when using BF% (OR = 1.38, 95% CI [1.13, 1.69]; p = 0.002) as the definition. The risk of sarcopenia reduced with the increase of BMI in both genders. It was increased with raised BF% in males but displayed a U-shaped curve for females. BF% 26.0-34.6% in old females and lower than 23.9% in old males are recommended for sarcopenia and obesity prevention.

Conclusion

Skeletal muscle mass had strong positive relationship with absolute fat mass but negative associations with the percentage of appendicular fat mass. Obesity was a risk factor of sarcopenia when defined by BF% instead of BMI. The management of BF% can accurately help elderly people prevent against both sarcopenia and obesity.

Muscle distribution in relation to all-cause and cause-specific mortality in young and middle-aged adults

BACKGROUND

The relationship between muscle and prognosis, especially that between muscle distribution across different body parts, and the related prognosis is not well established.

OBJECTIVE

To investigate the relationship between muscle distribution and all-cause and cause-specific mortality and their potential modifiers.

DESIGN

Longitudinal cohort study. C-index, IDI, and NRI were used to determine the best indicator of prognosis. COX regression analysis was performed to explore the relationship between variables and outcomes. Interaction and subgroup analyses were applied to identify the potential modifiers.

PARTICIPANTS

A total of 5052 participants (weighted: 124,841,420) extracted from the NHANES 2003-2006 of median age 45 years and constituting 50.3% men were assessed. For validation, we included 3040 patients from the INSCOC cohort in China.

MAIN MEASURES

Muscle mass and distribution. KEY RESULTS: COX regression analysis revealed that upper limbs (HR = 0.41, 95% CI 0.33-0.51), lower limbs (HR = 0.54, 95% CI 0.47-0.64), trunk (HR = 0.71, 95% CI, 0.59-0.85), gynoid (HR = 0.47, 95% CI 0.38-0.58), and total lean mass (HR = 0.55, 95% CI 0.45-0.66) were all associated with the better survival of participants (P trend < 0.001). The changes in the lean mass ratio of the upper and lower limbs and the lean mass ratio of the android and gynoid attenuated the protective effect of lean mass. Age and sex acted as potential modifiers, and the relationship between lean mass and the prognosis was more significant in men and middle-aged participants when compared to that in other age groups. Sensitive analyses depicted that despite lean mass having a long-term impact on prognosis (15 years), it has a more substantial effect on near-term survival (5 years).

CONCLUSION

Muscle mass and its distribution affect the prognosis with a more significant impact on the near-term than that on the long-term prognosis. Age and sex acted as vital modifiers.

Doubly labelled water-calibrated energy intake associations with mortality risk among older adults

BACKGROUND

The body mass index (BMI) is closely related to mortality risk, and energy intake (EI) is essential for maintaining energy balance in weight control. However, self-reported EI has been shown to lead to a systematic underestimation. Total energy expenditure measured using the doubly labelled water (DLW) method is considered an objective biomarker of EI and the gold standard for its estimation in individuals with stable body weight. We aimed to examine the association between DLW-calibrated EI and BMI on overall mortality risk in older adults.

METHODS

A prospective cohort study was performed using data of 8051 (4267 women and 3784 men) Japanese older adults from the Kyoto-Kameoka Study in Japan. Calibrated EI was calculated from the estimated EI using a food frequency questionnaire and equation developed based on DLW. Participants were classified by quartiles based on their EI stratified by sex. BMI was calculated using self-reported height and body weight. Mortality data were collected between 30 July 2011 and 30 November 2016. Statistical analysis was performed using the multivariable-adjusted Cox proportional hazard model with a restricted cubic spline.

RESULTS

The 8051 participants' mean (standard deviation) age and BMI were 73.5 (6.1) years and 22.6 (3.0) kg/m2 , respectively. The mean (standard deviation) EI with and without calibration was 1909 (145) kcal/day and 1569 (358) kcal/day in women and 2383 (160) kcal/day and 1980 (515) kcal/day in men, respectively. During the median 4.75 years of follow-up (36 552 person-years), 661 deaths were recorded. In both women (hazard ratio [HR], 0.63; 95% confidence interval [CI] [0.41, 0.98]) and men (HR, 0.62; 95% CI [0.44, 0.87]), after adjusting for confounders, the top quartile as compared with the bottom calibrated EI quartile showed a negative association with risk of all-cause mortality. The lowest HR for all-cause mortality was 1900-2000 kcal/day in women and 2400-2600 kcal/day in men. However, after adjusting for BMI, no significant association was observed between the calibrated EI and the risk of death. These associations could not be confirmed in the uncalibrated EI. The HR for mortality was minimal at a BMI of 23 kg/m2 in both men and women, with or without adjustment for the calibrated EI.

CONCLUSIONS

Calibrated EI was negatively associated with mortality risk but not uncalibrated EI. This may be mediated by an increase in body weight over time. Caution is required when interpreting the association between EI and mortality risk without adjusting for self-reported measurement errors and outcomes.

Deciphering the "obesity paradox" in the elderly: A systematic review and meta-analysis of sarcopenic obesity

Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age-related sarcopenia and obesity, has become a pressing issue. This systematic review and meta-analysis summarize the current clinical evidence relevant to SO. PubMed, Embase, and Web of Science were searched, and 106 clinical studies with 167,151 elderlies were included. The estimated prevalence of SO was 9% in both men and women. Obesity was associated with 34% reduced risk of sarcopenia (odds ratio [OR] 0.66, 95% CI 0.48-0.91; p < 0.001). The pooled hazard ratio (HR) of all-cause mortality was 1.51 (95% CI 1.14-2.02; p < 0.001) for people with SO compared with healthy individuals. SO was associated with increased risk of cardiovascular disease and related mortality, metabolic disorders, cognitive impairment, arthritis, functional limitation, and lung diseases (all ORs > 1.0, p < 0.05). The attenuated risk of sarcopenia in elderlies with obesity ("obesity paradox") was dependent on higher muscle mass and strength. Apart from unifying the diagnosis of SO, more research is needed to subphenotype people with obesity and sarcopenia for individualized treatment. Meanwhile, the maintenance of proper body composition of muscle and fat may delay or attenuate the adverse outcomes of aging.

Changes in daily sleep duration and subsequent risk of mortality among older people

BACKGROUND

Single self-reported measures of daily sleep duration are associated with adverse health outcomes; however, the association between changes in daily sleep duration and all-cause mortality has not been thoroughly evaluated among a large group of older people.

METHODS

Using data from the Chinese Longitudinal Healthy Longevity Surveys, a total of 8588 older participants were included in the present study. Changes in daily sleep duration were assessed using annual changes, and Cox regression analysis examined the association of the annual changes with mortality.

RESULTS

The median age of the study population was 82.00 (IQR: 72.00, 90.00) years, and 3974 (46.27%) participants were men. During a median follow-up period of 3.81 (IQR: 2.03, 6.74) years, 5100 (59.39%) deaths were recorded. After adjusting for initial daily sleep duration and other confounders, there was a non-linear relationship between annual changes in daily sleep duration and all-cause mortality. Annual changes were not associated with mortality before 0.0 h/year, and mortality risk increased after 0.0 h/year, specially after 1 h/year (adjusted HR: 1.32 per 1-hour/year increment, 95% CI: 1.18-1.47). Compared to the stable group (annual changes between -1 and 1 h), adjusted HRs for mortality were 0.98 (95% CI: 0.89-1.08) for the shorter group (annual decline more than 1 h) and 1.29 (95% CI: 1.19-1.41) for the longer group (annual increase greater than 1 h), respectively. Stratified and sensitivity analyses suggested robustness of the results.

CONCLUSIONS

The present study suggested there was a non-linear relationship between annual changes in daily sleep duration and all-cause mortality among older people: longer changes were associated with higher mortality; while, shorter changes were not associated with mortality. Specially, mortality risk increased significantly with longer than 1 h of annual changes. The findings highlight the importance of closely monitoring the changes in daily sleep duration among older people.

The path to healthy ageing in China: a Peking University-Lancet Commission

Around the world, populations are ageing at a faster pace than in the past and this demographic transition will have impacts on all aspects of societies. In May 2020, the UN General Assembly declared 2021–2030 the Decade of Healthy Ageing, highlighting the importance for policymakers across the world to focus policy on improving the lives of older people, both today and in the future. While rapid population ageing poses challenges, China’s rapid economic growth over the last forty years has created space for policy to assist older persons and families in their efforts to improve health and well-being at older ages. As China is home to 1/5 of the world’s older people, China is often held up as an example for other middle-income countries. This Commission Report aims to help readers to understand the process of healthy ageing in China as a means of drawing lessons from the China experience. In addition, with the purpose of informing the ongoing policy dialogue within China, the Commission Report highlights the policy challenges on the horizon and draws lessons from international experience.

Relationship between physical activity and incidence of dementia in people aged 50 and over in Europe

OBJECTIVE

The aim of this study was to analyse the relationship between physical activity and the incidence of dementia in a cohort of people aged 50 years or older without dementia from different countries in Europe between the years 2013 and 2015.

METHODS

Prospective longitudinal design study (2013-2015) with a sample of 46,141 people without dementia in 2013 who participated in the SHARE project in waves 5 and 6, where 15 European countries participated. We defined dementia as a self-report of Alzheimer's disease, organic brain syndrome, senility, or any other serious memory impairment during follow-up. The frequency of moderate, vigorous and moderate-to-vigorous physical activity in 2013 was obtained from a validated questionnaire. Incidences of dementia by year (between 2013 and 2015) were calculated for each category of physical activity. Poisson regression models with robust variance were fitted for the association between physical activity and dementia.

RESULTS

The incidence of dementia was 7.4 [95%CI = 6.8-7.9] cases per 1000 persons per year. Very frequent moderate physical activity is a protective factor for dementia independently of the frequency of vigorous physical activity and inversely. The risk of dementia was 2.36 [95%CI = 1.77-3.14] higher in people who hardly ever, or never did moderate-to-vigorous physical activity comparing to people engaged in it more than once a week independently of the baseline cognitive level.

CONCLUSION

Physical activity is associated with the incidence of dementia in people aged 50 and over in both men and women in Europe.