Association between Body Mass Index and All-Cause Mortality among Oldest Old Chinese

Healthy Lifestyle and the Likelihood of Becoming a Centenarian

Importance

Previous studies have reported that lifestyle factors were associated with life expectancy and/or mortality, but most of them studied the middle-aged or older age groups (aged ≥60 years), and few focused on people aged 80 years or older.

Objectives

To examine healthy lifestyle and the likelihood of becoming centenarians among people aged 80 years or older in China.

Design, Settings, and Participants

Using data from the Chinese Longitudinal Healthy Longevity Survey, a nationally representative and one of the largest prospective cohorts targeting people aged 80 years or older established in 1998, a community-based, prospective nested case-control study was performed. Data were analyzed from December 1, 2022, to April 15, 2024.

Exposures

A healthy lifestyle score for 100 (HLS-100, ranging from 0 to 6), including smoking, exercise, and dietary diversity, was constructed, with higher scores indicating potentially better health outcomes.

Main Outcomes and Measures

The primary outcome was survivorship to becoming a centenarian by 2018 (the end of follow-up). Information on sociodemographic characteristics, lifestyle factors, and other covariates was collected.

Results

The sample comprised 5222 individuals (61.7% women, mean [SD] age, 94.3 [3.3] years), including 1454 identified centenarians and 3768 controls (died before becoming centenarians) matched by age, sex, and year of entry. During a median follow-up of 5 (IQR, 3-7) years, 373 of 1486 individuals among the lowest HLS-100 (0-2) group and 276 of 851 individuals among the highest HLS-100 (5-6) group became centenarians. The adjusted odds ratio (AOR) comparing the highest vs the lowest HLS-100 groups was 1.61 (95% CI, 1.32-1.96; P < .001 for trend). An association was noted when we further treated centenarians with relatively healthy status as the outcome, as evaluated by self-reported chronic conditions, physical and cognitive function, and mental wellness (AOR, 1.54; 95% CI, 1.05-2.26). Similar results were observed in other sensitivity analyses.

Conclusions and Relevance

In this case-control study of Chinese older adults, adhering to a healthy lifestyle appears to be important even at late ages, suggesting that constructing strategic plans to improve lifestyle behaviors among all older adults may play a key role in promoting healthy aging and longevity.

Association of cooking oil and incident of frailty in older adults: a cohort study

BACKGROUND

Studies examining the potential association between cooking oil and frailty risk in older adults have produced conflicting outcomes. Therefore, our objective was to explore the relationship between cooking oil (vegetable and animal fat oils), changes in oil usage, and the risk of frailty in older adults.

METHODS

We included 4,838 participants aged ≥ 65 years without frailty (frailty index < 0.25) from the 2011 wave of the Chinese Longitudinal Healthy Longevity Survey. Follow-up occurred in the 2014 and 2018 waves. Cox proportional hazard models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to examine the association between cooking oil and frailty. Additionally, we evaluated the effect of switching cooking oil on frailty during the follow-up period.

RESULTS

During a median follow-up of 3.0 (2.8-6.9) years, 1,348 individuals (27.9%) developed frailty. Compared to those using vegetable oil, users of animal fat oil had a lower risk of frailty (HR = 0.72, 95% CI: 0.61-0.85). Participants who switched from vegetable oil to animal fat oil, as well as those consistently using animal fat oil, had lower risks of frailty with HRs of 0.70 (0.52-0.95) and 0.63 (0.51-0.77) respectively, compared to those who consistently used vegetable oil. Conversely, individuals who switched from animal fat oil to vegetable oil experienced an increased risk of frailty (HR: 1.41, 95% CI: 1.01-1.97).

CONCLUSIONS

The utilization of animal fat oil in cooking exhibited a reduced frailty risk among older adults. Conversely, transitioning from animal fat oil to vegetable oil may elevate the risk. These findings propose that substituting vegetable oil with animal fat oil in the diet may safeguard against frailty.

Dietary factors in relation to the risk of cognitive impairment and physical frailty in Chinese older adults: a prospective cohort study

PURPOSE

The study aimed to investigate the independent associations of dietary factors with cognitive impairment (CI) and physical frailty (PF) among Chinese older adults.

METHODS

This study included 10,734 participants (mean age = 78.7 years) free of CI and PF at baseline from the Chinese Longitudinal Health Longevity Survey. Dietary intake was collected using a simplified food frequency questionnaire every 3-4 years. The Chinese version Mini-Mental State Examination was used to assess cognition function, participants with a score below 18 were defined as CI. PF was defined using the activities of daily living, instrumental activities of daily living, and functional limitation-related questions. The outcome was defined as the first onset of either CI or PF. Competing risk models were used to estimate the corresponding hazard ratios (HRs) and the 95% confidence intervals (95% CIs).

RESULTS

During the study follow-up (mean = 8.1 years), a total of 1220 CI cases and 1451 PF cases were newly identified. Higher frequency of fruits intake was associated with a lower hazard of CI (HR = 0.75, 95% CI 0.58-0.97), whereas higher intake of preserved vegetables demonstrated an opposite association (HR = 1.23, 95% CI 1.07-1.42). In terms of PF, we observed a lower risk associated with higher meat and poultry intake (HR = 0.72, 95% CI 0.61-0.88). In particular, a significant protective association of fish and aquatic products intake with PF was observed among participants with ≥ 28 natural teeth (HR = 0.52, 95% CI 0.27-0.99).

CONCLUSION

Our findings suggest divergent roles of major dietary factors in the development of CI and PF among Chinese older adults.

Is waist-calf circumference ratio associated with frailty in older adults? Findings from a cohort study

BACKGROUND

The waist-calf circumference ratio (WCR) has been suggested as a potential indicator of visceral adiposity. Nevertheless, the relationship between WCR and the risk of frailty remains unclear. Therefore, our study aimed to investigate the association between WCR and longitudinal changes in WCR with frailty risk in older adults.

METHODS

We included 2359 participants aged ≥ 65 years without frailty (frailty index [FI] ≤ 0.21) from the Chinese Longitudinal Healthy Longevity Survey in the 2014 wave. The follow-up was conducted in 2018. We investigated the relationship of WCR, waist circumference (WC), and calf circumference (CC) with frailty using both the Cox proportional hazards model and the generalized estimating equation (GEE).

RESULTS

During a median follow-up of 4.0 years, 668 (28.2%) frailty occurred. Those with higher WCR and WC had a significantly increased risk of frailty (fifth quintile compared with first quintile: hazard ratio [HR] = 1.59, 95% confidence interval [CI] 1.24-2.04 for WCR; HR = 1.69, 95% CI 1.27-2.24 for WC), whereas those in the fourth quintile of CC had a lower likelihood of developing frailty compared to those in the first quintile (HR = 0.67, 95% CI 0.50-0.89). Interaction analyses showed that the effects of WCR on frailty were more pronounced in females (P-interaction = 0.016). GEE analyses revealed that increased WCR and WC were associated with a higher risk of frailty (odds ratio [OR] = 1.74, 95% CI 1.43-2.12 for WCR; OR = 1.03, 95% CI 1.02-1.04 for WC), while CC showed opposite results (OR = 0.95, 95% CI 0.93-0.97).

CONCLUSIONS

A higher WCR and WC, as well as a lower CC, were significantly associated with higher frailty. Of these measures, WCR demonstrated the strongest association with frailty, suggesting that having a combination of high central fat and low lean body mass may increase the risk of developing frailty.

Living Alone Increases the Risk of Hypertension in Older Chinese Adults: A Population-Based Longitudinal Study

Background and Objectives

Cross-sectional studies have suggested a potential association between living alone and hypertension risk, but longitudinal evidence remains limited. We aimed to investigate the correlation between living alone, alterations in living arrangements, and hypertension risk among older adults utilizing a population-based longitudinal design.

Research Design and Methods

The study included 8 782 older adults (≥65 years) without hypertension from the Chinese Longitudinal Healthy Longevity Survey. Participants were surveyed during the 2008 and 2011/2012 waves and were subsequently followed up in the next wave. Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg, or a self-reported diagnosis of hypertension by a physician. Cox proportional hazards model was used to explore the association between living alone and hypertension. Additionally, we analyzed how switching living arrangements during the follow-up period affects hypertension.

Results

During a median follow-up of 2.8 (1.7-3.0) years, 2 750 hypertension events occurred. Compared with living with family, the hazard ratio (HR) (95% confidence interval [CI]) of living alone was 1.19 (1.06-1.33) for hypertension. Similarly, persisting in living alone during follow-up increased the risk of hypertension compared to continuing to live with family (HR 1.24; 95% CI: 1.06-1.45). Compared to married participants who continued to live with family, widowed/divorced participants who transitioned from living with family to living alone experienced a higher risk of hypertension (HR 1.21; 95% CI: 1.00-1.47). Stratified analyses showed that living alone was only associated with an increased hypertension risk for participants aged >80, men, and rural residents.

Discussion and Implications

Living alone at baseline or persisting in living alone during follow-up correlated with increased hypertension risk. Divorced or widowed individuals who transitioned from living with family to living alone were still at risk. These results indicate that social support and living arrangements may be important in preventing hypertension in older adults.

Is Chinese Spring Festival a key point for glycemic control of patients with type 2 diabetes mellitus in China?

Objectives

This study aims to explore the long-term trend of fasting blood glucose (FBG) among urban patients with type 2 diabetes mellitus (T2DM) and the impacts of the Chinese Spring Festival on their glycemic control in urban China.

Methods

The general information and longitudinal monitoring data of patients with T2DM in Minhang District, Shanghai China from 15 December 2006 to 31 December 2015 were collected. The FBG records were grouped into three periods, namely, the preholiday period (2 months right before the Chinese Spring Festival), the holiday period (from 28 December to 7 January of the lunar calendar year), and the postholiday period (2 months after the Chinese Spring Festival). The Mann-Kendall trend test and Cochran-Armitage trend test were occupied to explore the long-term trend, and paired t-test and chi-square (χ²) test were used to determine the differences in glycemic level and control rate between the preholiday and postholiday periods, respectively.

Results

From 2007 to 2015, the glycemic control rate in patients with T2DM showed an upward trend (P < 0.001), and the FBG level showed a decreasing trend (P = 0.048). After the Chinese Spring Festival, the glycemic control rate decreased significantly (P < 0.001), and the FBG level increased significantly (P < 0.001) compared to those during the preholiday period. The incidence of hypoglycemia increased during holidays. Patients who were aged 60-69 years, overweight or obese, with hypertension, with a disease duration of <3 years, or with poor glycemic control in one previous year were more likely to be affected by the holiday.

Conclusion

Chinese Spring Festival is a key point for glycemic control of patients with T2DM in China. Intensive holiday-specific diabetic healthcare needs to be further improved, and community-based interventions should be developed and implemented to control the possible holiday effects.

Gender differences in the correlation between body mass index and cognitive impairment among the community-dwelling oldest-old in China: a cross-sectional study

OBJECTIVE

This study investigates gender differences in the correlation between body mass index (BMI) and cognitive impairment among Chinese community-dwelling oldest-old.

SETTING

Twenty-three provinces in China. Participants' mini-mental state examination (MMSE) scores <24 were considered cognitive impairment. Furthermore, the assessment standards of BMI status were classified into four categories: obese (BMI >30), overweight (25≤BMI≤30), normal (18.5≤BMI<25) and underweight (BMI <18.5).

PARTICIPANTS

A total of 9218 older adults (age 80+) were included from the 2018 wave of Chinese Longitudinal Healthy Longevity Study.

METHODS

Cognitive impairment, BMI and other covariates consisted of the sociodemographic variables, health behaviours and health status were collected. Cognitive impairment was assessed by the MMSE. Inverse probability weighting procedure was adopted to deal with bias due to dropout.Logistic regression was conducted to examine the correlation between BMI and cognitive impairment.

RESULTS

Among 9218 respondents, 3837 were males. Overall, the percentage of participants with cognitive impairment was 44.7%, with 32.1% among males and 53.7% among females. After controlling for other variables, males who were either overweight or underweight and females who were underweight were found to have higher risk of cognitive impairment among the oldest-old. Age, education, economic status, physical activity, activities of daily living, hypertension as well as heart disease were the predicting factors of cognitive impairment.

CONCLUSIONS

The relationship between BMI and cognitive impairment differs between male and female oldest-old, suggesting that we should pay attention to different BMI groups and adopt precise prevention strategies based on gender.

Health consequences of obesity and projected future obesity health burden in China

OBJECTIVE

This study examined the effects of overweight/obesity on mortality and morbidity outcomes and the disparities, time trends, and projected future obesity health burden in China.

METHODS

Cohort studies that were conducted in China and published in English or Chinese between January 1, 1995, and July 31, 2021, were systematically searched. This study focused on overweight/obesity, type 2 diabetes mellitus (T2DM), hypertension, cardiovascular diseases, metabolic syndrome, cancers, and chronic kidney disease.

RESULTS

A total of 31 cohorts and 50 cohort studies reporting on mortality (n = 20) and morbidities (n = 30) associated with obesity met study inclusion criteria. Overall, BMI was nonlinearly (U-shaped) associated with all-cause mortality and linearly associated with risks of T2DM, cardiovascular diseases, hypertension, cancer, metabolic syndrome, and chronic kidney disease. In 2018, among adults, the prevalence of overweight/obesity, hypertension, and T2DM was 51.2%, 27.5%, and 12.4%, respectively. Their future projected prevalence would be 70.5%, 35.4%, and 18.5% in 2030, respectively. The projected number of adults having these conditions would be 810.65 million, 416.47 million, and 217.64 million, respectively. The urban-rural disparity in overweight/obesity prevalence was projected to shrink and then reverse over time.

CONCLUSIONS

The current health burden of obesity in China is high and it will sharply increase in coming years and affect population groups differently. China needs to implement vigorous interventions for obesity prevention and treatment.

Perioperative blood loss during joint replacement: comparison between patients with and without hemophilia

Background

Although arthroplasty provides satisfactory pain relief, functional improvement, and reduced flexion contracture in patients with hemophilia arthropathy, bleeding remains the primary problem associated with hemophilic arthropathy joint replacement. We aimed to explore the differences in perioperative blood loss (PBL) associated with joint replacement surgery in patients with and without hemophilia.

Methods

This study retrospectively analyzed 61 cases of PBL in patients undergoing joint replacement surgery, including 37 patients with hemophilia and 24 patients without hemophilia. All patients demonstrated severe joint flexion contractures that seriously affected their daily lives and required surgical intervention. PBL was compared between the two groups.

Results

In univariate analysis, the overall (p < 0.001) and hidden (p < 0.001) blood losses were significantly higher for patients with hemophilia than those for patients without hemophilia. However, after adjustment for multiple factors, there was no significant difference in overall blood loss between the two groups (p = 0.731). In addition, sex, age group, and surgical site did not affect blood loss in patients with hemophilia.

Conclusion

Overt bleeding did not increase significantly in patients with hemophilia, compared with that in patients without hemophilia. In terms of blood loss, joint replacement surgery for patients with hemophilia is relatively safe. The results of this study must be verified by a prospective follow-up study with larger sample size.

Trial registration Retrospectively registered.

Association Between Body Mass Index and All-Cause Mortality in a Prospective Cohort of Southern Chinese Adults Without Morbid Obesity

Objective: This prospective study examined the relationship between body mass index (BMI) and all-cause mortality in Chinese adults without morbid obesity.

Methods: We prospectively examined the relationship between BMI and all-cause mortality in 12,608 Southern Chinese adults with age ≥35 years who participated in the National Key R&D Program from 2013–2014 to 2019–2020. Cox proportional hazards models were used to examine the association between BMI and all-cause mortality.

Results: The prevalence of being underweight, normal weight, overweight and having moderate obesity was 7.36%, 55.83%, 28.51% and 8.31%, respectively. A total of 683 (5.65%) deaths occurred during a median follow-up period of 5.61 years. The Cox proportional hazards models indicated that a continuous BMI level was negatively associated with all-cause mortality [adjusted-hazard ratio (HR) per 1 kg/m² increase: 0.96, 95% CI 0.93 to 0.98, p < 0.001]. Furthermore, the HRs of all-cause mortality in the underweight, overweight and moderate obesity groups were 1.31 (1.05, 1.64), 0.89 (0.73, 1.08) and 0.64 (0.44, 0.92), respectively in the confounder model relative to the normal weight group. Survival analysis further confirmed this inverse association of the four BMI categories with mortality.

Conclusion: BMI was negatively associated with all-cause mortality in southern Chinese adults without morbid obesity. Compared to the normal weight category, adults in the moderate obesity category had lower all-cause mortality, whereas being underweight was associated with increased all-cause mortality.

Development, validation, and visualization of a web-based nomogram to predict 5-year mortality risk in older adults with hypertension

Background

Hypertension-related mortality has been increasing in older adults, resulting in serious burden to society and individual. However, how to identify older adults with hypertension at high-risk mortality remains a great challenge. The purpose of this study is to develop and validate the prediction nomogram for 5-year all-cause mortality in older adults with hypertension.

Methods

Data were extracted from National Health and Nutrition Examination Survey (NHANES). We recruited 2691 participants aged 65 years and over with hypertension in the NHANES 1999-2006 cycles (training cohort) and 1737 participants in the NHANES 2007-2010 cycles (validation cohort). The cohorts were selected to provide at least 5 years follow-up for evaluating all-cause mortality by linking National Death Index through December 31, 2015. We developed a web-based dynamic nomogram for predicting 5-year risk of all-cause mortality based on a logistic regression model in training cohort. We conducted internal validation by 1000 bootstrapping resamples and external validation in validation cohort. The discrimination and calibration of nomogram were evaluated using concordance index (C-index) and calibration curves.

Results

The final model included eleven independent predictors: age, sex, diabetes, cardiovascular disease, body mass index, smoking, lipid-lowering drugs, systolic blood pressure, hemoglobin, albumin, and blood urea nitrogen. The C-index of model in training and validation cohort were 0.759 (bootstrap-corrected C-index 0.750) and 0.740, respectively. The calibration curves also indicated that the model had satisfactory consistence in two cohorts. A web-based nomogram was established (https://hrzhang1993.shinyapps.io/dynnomapp).

Conclusions

The novel developed nomogram is a useful tool to accurately predict 5-year all-cause mortality in older adults with hypertension, and can provide valuable information to make individualized intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03087-3.

Prevalence and correlates of obesity among the oldest old. A systematic review, meta-analysis and meta-regression

Thus far, the prevalence and correlates of obesity among the oldest have been identified in several studies. Nevertheless, there is a lack of a systematic review, meta-analysis and meta-regression synthesizing the existing observational studies. Consequently, our aim was to fill this knowledge gap. Three electronic databases were searched (Medline, PsycINFO, CINAHL) and an additional hand search was performed. Observational studies (both, cross-sectional and longitudinal) determining the prevalence and (preferably) the correlates of obesity in the oldest old (≥80 years) were included. Data extraction covered study design, measurement of obesity, analytical approach, sample characteristics and main results. In total, 19 studies were included. Reported prevalence of obesity in the community varied greatly (range 0.7%-71.5%). The pooled prevalence of obesity was 17.8% (95% CI: 13.3%-22.2%), with significant heterogeneity between studies (I²  = 99.7%, P < 0.001). There is evidence of a publication bias. Meta-regressions showed that some of the heterogeneity was explained by the types of measures of obesity and country of the respective sample. In conclusion, obesity remains a key challenge among the oldest old. Future research in this age bracket is urgently required in regions mostly neglected thus far (e.g., South America, Africa or Asia). Moreover, studies based on longitudinal data are required to clarify the determinants of obesity among the oldest old. Furthermore, studies based on objectively recorded obesity (e.g., waist circumference) are also required. Geriatr Gerontol Int 2022; 22: 373-383.

Body mass index and 12-year mortality among older Mexican Americans aged 75 years and older

Background

The role of obesity in mortality in the very old and old-oldest Hispanic population has not been studied. The objective of this study was to examine the effect of body mass index (BMI) on 12-year mortality among older Mexican Americans aged 75 years and older.

Methods

Twelve year prospective cohort study consisting of a population-based sample of 1415 non-institutionalized Mexican American men and women aged 75 and older from 5 southwestern states: Arizona, California, Colorado, New Mexico, and Texas. Data was from Wave 5 of the Hispanic Established Population for the Epidemiologic Study of the Elderly (2004/2005–2016). Socio-demographics, body mass index (BMI), self-reported medical conditions, disability, depressive symptoms, falls, Mini-Mental-State-Examination (MMSE), and Short Physical Performance Battery (SPPB) were assessed at baseline during 2004–2005. BMI (Kg/m²) was classified as underweight (< 18.5), normal weight (18.5 to < 25), overweight (25 to < 30), obesity category I (30 to < 35), and obesity category II/morbid obesity (≥ 35). For assessment of mortality, deaths were ascertained through the National Death Index and report from relatives. Cox proportional hazards regression analysis was performed to estimate the hazard ratio (HR) of 12-year mortality as a function of BMI categories at baseline.

Results

The mean BMI was 27.5 ± 1.7 with participants classified as 1.8% underweight, 30.8% normal weight, 39.2% overweight, 20.7% obesity category I, and 7.6% obesity category II/morbid obesity. Mexican Americans aged ≥75 years with overweight or obesity category I had a reduced HR of death (0.82, 95% CI = 0.70–0.96 and 0.75, 95% CI = 0.62–0.91, respectively) over 12-years of follow-up. The HR of death for underweight and obesity category II/morbid obesity participants was 1.59 (95% CI = 1.03–2.45) and 1.12 (95% CI = 0.85–1.46), respectively. Female participants and those with high scores in the MMSE and SPPB had decreased risk of death.

Conclusions

This study showed the protective effect of overweight and obesity on mortality in Mexican Americans above 75 years of age, which might have implications when treating older adults with overweight and obesity.

Association of using biomass fuel for cooking with depression and anxiety symptoms in older Chinese adults

BACKGROUNDS

Household air pollution exposure is a crucial public concern and have the potential to seriously affect human health. Using biomass fuels for cooking is the main contributor to household air pollution. However, current evidence linked between cooking with biomass fuels and mental health remains limited.

OBJECTIVES

To explore whether cooking with biomass fuels is associated with depression and anxiety symptoms among older adults in China.

METHODS

We obtained data from Chinese Longitudinal Healthy Longevity Survey (CLHLS). Depressive and anxiety symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10) and the 7-item Generalized Anxiety Disorder Scale (GAD-7), respectively. Primary cooking fuel type was self-reported. We used logistic regression and linear regression to evaluate the effects of cooking with biomass fuels on depression and anxiety.

RESULTS

A total of 13,361 participants aged 65 years and older (mean age, 84.2 ± 11.5 years) were included in the presented study. A positive association was found between cooking with biomass fuels and both depression symptoms (adjusted odds ratio 1.23, 95% CI 1.03 to 1.47) and anxiety symptoms (adjusted odds ratio 1.31, 95% CI 1.02 to 1.68). Biomass fuel users had a higher depression scores (0.33, 95% CI 0.03 to 0.61) and a higher anxiety scores (0.20, 95% CI 0.02 to 0.38) compared to clean fuel users. We found no significant interactions between participant characteristics and biomass fuel use on either depression or anxiety symptoms.

CONCLUSIONS

Cooking with biomass fuels was associated with depression and anxiety symptoms in order adults. Further large prospective cohort studies are warranted to confirm this association.

Behavioral Lifestyles and Survival: A Meta-Analysis

The aim of the study is to determine the association between Behavioral Lifestyles (regular physical activity, healthy diet, sleeping, and weight control) and longevity in the elderly. A search strategy was conducted in the PsycInfo, Medline, PubMed, Web of Science (WoS), and Scopus databases. The primary outcome was mortality/survival. Four variables (mean of participant's age at the baseline of the study, follow-up years of the study, gender, and year of publication) were analyzed to evaluate the role of potential moderators. Ninety-three articles, totaling more than 2,800,000 people, were included in the meta-analysis. We found that the lifestyles analyzed predict greater survival. Specifically, doing regular physical activity, engaging in leisure activities, sleeping 7-8 h a day, and staying outside the BMI ranges considered as underweight or obesity are habits that each separately has a greater probability associated with survival after a period of several years.

Development of the cMIND Diet and Its Association with Cognitive Impairment in Older Chinese People

OBJECTIVES

Cognitive impairment commonly occurs among older people worldwide. Although the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet was associated with better cognitive function and lower risk of cognitive impairment, it could not be applied to older Chinese due to the traditional dietary characteristics in China. We aimed to develop the Chinese version of the MIND (cMIND) diet and verify its association with cognitive impairment among older Chinese individuals.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

We included a total of 11,245 participants from the Chinese Longitudinal Healthy Longevity Study (CLHLS) follow-up survey in 2018. The mean age of the participants at study baseline was 84.06 (±11.46) years.

MEASUREMENTS

We established the cMIND diet based on current evidence in the diet-cognition field, combined with Chinese dietary characteristics. The verification of its association with cognitive impairment was conducted using the data from the CLHLS follow-up survey. Adherence to the cMIND diet was assessed by the cMIND diet score, which was calculated from a food frequency questionnaire. Cognitive impairment was identified by the Mini-Mental State Examination. Instrumental activities of daily living (IADL) disability was defined according to the self-reported performance of eight activities.

RESULTS

The cMIND diet comprised 11 brain-healthy food groups and 1 unhealthy food group. The median cMIND diet score of all participants was 4.5 (from a total of 12 points) and the prevalence of cognitive impairment was 15.2%. Compared with the lowest tertile, the highest tertile score was associated with lower odds of cognitive impairment (odds ratio (OR)=0.60, 95% confidence interval (CI): 0.51-0.72) and IADL disability (OR=0.86, 95% CI: 0.75-0.98) in the full-adjusted model.

CONCLUSION

We developed the cMIND diet that was suitable for older Chinese individuals, and our results suggested that higher adherence to the cMIND diet was associated with reduced odds of cognitive impairment and IADL disability. In view of the limitations of cross-sectional design in the study, further research is clearly warranted.

Effects of Body Mass Index, Waist Circumference, Waist-to-Height Ratio and Their Changes on Risks of Dyslipidemia among Chinese Adults: The Guizhou Population Health Cohort Study

This study aimed to assess the effects of different anthropometric indices and their changes on the risk of incident dyslipidemia among the Chinese population. From the Guizhou population health cohort study, 2989 Chinese adults without dyslipidemia at baseline were followed up. Anthropometric parameters including waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), and their changes in the latter two indices, and serum lipids were tested after at least 8 h fasting. Hazard ratio (HR), adjusted hazard ratio (aHR), and 95% confidential interval (CI) were calculated to estimate the association between anthropometric parameters and dyslipidemia risk using multivariate Cox regression. A total of 2089 (69.98%) new dyslipidemia cases were identified over an average follow-up of 7.0 years. Baseline BMI (aHR = 1.12, 95%CI 1.01, 1.23) and WHtR (aHR = 1.06, 95%CI 1.00, 1.13) were positively associated with higher risks of incident dyslipidemia but not WC. Each 5.0 kg/m² increment of BMI or 0.05-unit increment of WHtR was significantly associated with 43% or 25% increased risk of incident dyslipidemia, respectively. The aHRs (95%CI) of incident dyslipidemia for subjects maintaining or developing general obesity were 2.19 (1.53, 3.12) or 1.46 (1.22, 1.75), and 1.54 (1.23, 1.82) or 1.30 (1.06, 1.60) for subjects maintaining or developing abdominal obesity, respectively. Linear trends for aHRs of BMI, WHtR change, and BMI change were observed (p for trend: 0.021, <0.001, <0.001, respectively). BMI, WHtR, and their changes were closely associated with the incidence of dyslipidemia for Chinese adults. Loss in BMI and WHtR had protective effects on incident dyslipidemia, whereas gain of BMI or WHtR increased the dyslipidemia risk. Interventions to control or reduce BMI and WHtR to the normal range are important for the early prevention of dyslipidemia, especially for participants aged 40 years or above, male participants, and urban residents with poor control of obesity.

Combined effect of obesity and low physical performance on the incidence of hypertension in Chinese community-dwelling older population

The combination of having a low physical performance and obesity results in a vicious cycle, but the effect of this combination on the incidence of hypertension is still unknown. This article aims to examine the effect of obesity and low physical performance on the incidence of hypertension in older adults. The sample was comprised of 349 Chinese community-dwelling participants (199 women; mean age 66.30 ± 5.78 years) without hypertension at baseline. Obesity was defined as having a body mass index (BMI) greater than or equal to 28 kg/m². Participants scoring in the top 20% on the Timed Up and Go Test (TUGT) or in the slowest 20% of the 4-m walking test were defined as having a low physical performance. The outcome was new onset hypertension at the 1-year follow-up. We found that 89 (25.5%) of the 349 participants without hypertension at baseline had developed hypertension at their 1-year follow-up. After multivariate adjustments, it was found that the incidence of hypertension was associated with the combination of obesity and having a low physical performance (OR = 7.30, 95% CI = 1.36-39.11), but not solely with obesity (OR = 1.40, 95% CI = 0.68-2.88) or solely with low physical performance (OR = 0.98, 95% CI = 0.29-3.27). Hence, although obesity and low physical performance did not independently affect the incidence of hypertension after one year, the combination of the two can significantly increase the incidence of hypertension in Chinese community-dwelling older adults.

Cooking with biomass fuels increased the risk for cognitive impairment and cognitive decline among the oldest-old Chinese adults (2011-2018): A prospective cohort study

BACKGROUNDS

While the pernicious effects of outdoor air pollution on cognitive ability have been previously examined, evidence regarding household air pollution is scarce.

METHODS

Using data from the Chinese Longitudinal Healthy Longevity Survey, we explored the relationship between cooking with biomass fuel and cognitive impairment and cognitive decline using a Cox proportional hazards model. We further assessed the correlation of biomass fuels and cognitive score using a generalized estimating equation. Cognitive ability was measured based on the Chinese version of the Mini-Mental State Examination (MMSE) and cognitive impairment was defined as MMSE < 24 points and cognitive decline was defined as a reduction of MMSE ≥ 3 points. On follow-up, we investigated the effect of switch-cooking combustibles on cognitive ability.

RESULTS

The mean (SD) age of 4161 participants was 81.7 (10.0) years old. The reported cooking with biomass fuels was correlated with an elevated risk of cognitive impairment (hazard ratio (HR): 1.19, 95% confidence interval (CI): 1.04, 1.37) and cognitive decline (HR: 1.18, 95% CI: 1.04, 1.33). Besides, cooking with biomass fuels was related to a decrease in cognitive score (β: -0.43, 95% CI: -0.73, -0.14). In comparison to persistent biomass fuel users, participants who reported changing their primary cooking fuels from biomass to clean fuels exhibited a reduced risk of cognitive impairment (HR: 0.68, 95% CI: 0.57, 0.82) and cognitive decline (HR: 0.66, 95% CI: 0.56, 0.76) and a higher cognitive score (β: 0.72, 95% CI: 0.17, 1.26). Cooking without ventilated cookstoves was associated with a higher risk of cognitive impairment (HR: 1.31, 95% CI: 1.10, 1.58) and cognitive decline (HR: 1.18, 95% CI: 1.02, 1.38), regardless of types of cooking fuels. Interaction and stratified analyses showed relatively poor cognitive ability in participants who engaged in irregular exercise or were not living with family members.

CONCLUSIONS

Cooking with biomass fuels was correlated with a higher risk of cognitive impairment and cognitive decline. Among the oldest-old population, this risk may, however, be lower for those changing their primary cooking fuels from biomass to clean fuels.

Independent and joint associations of body mass index, waist circumference, waist-height ratio and their changes with risks of hyperuricemia in middle-aged and older Chinese individuals: a population-based nationwide cohort study

Background

Previous reports regarding the predictive power of adiposity indices remain inconsistent, and longitudinal studies on this top are limited. The associations of hyperuricemia risk with changes in obesity status, as well as the joint effects of baseline adiposity indices and body adiposity change on hyperuricemia risk are not fully elucidated. This study aimed to explore the independent and joint associations of baseline adiposity indicators and body adiposity change with hyperuricemia risk among middle-aged and older population in China.

Methods

A total of 2895 participants aged ≥ 45 years from the baseline survey of the China Health and Retirement Longitudinal Study were followed up for 4 years. Anthropometric parameters (weight, height, and waist circumference) and serum uric acid were obtained using standard devices. Adjusted odds ratio and 95% confidential interval were calculated to estimate the associations between predictor variables and hyperuricemia risk using multivariate logistic regression.

Results

Of the 2895 participants, 293 (10.12%) cases of hyperuricemia were identified. Increased baseline body mass index (BMI), waist circumference, and waist-height ratio (WHtR) were significantly associated with higher risks of hyperuricemia. A slightly greater but non-significant area under the curve value was observed for waist circumference (0.622) than for BMI (0.611) and WHtR (0.614) (P = 0.447). Compared to subjects with stable adiposity status, participants with weight loss of ≥ 4 kg or waist circumference loss of ≥ 6 cm had a 56% or 55% lower risk of hyperuricemia, and those with weight gain of > 4 kg had a 1.62-fold higher risk of hyperuricemia. Compared to those without obesity, participants with incident or persistent obesity were more likely to develop hyperuricemia. Additionally, regardless of stable or increased weight/waist circumference during follow-up, individuals with obesity at baseline had a higher risk of incident hyperuricemia.

Conclusion

This study demonstrates that BMI, waist circumference, and WHtR equally predict the development of hyperuricemia, and weight loss and waist circumference reduction are favorable in preventing hyperuricemia.

Synergistic Impact of Body Mass Index and Cognitive Function on All-Cause Mortality in Older Adults: A Nationwide Longitudinal Study

BACKGROUND

Body mass index (BMI) and cognitive function are independent predictors of mortality risk. However, little is known about the combined impact of BMI and cognitive function on the risk of all-cause mortality in older adults. In this study, we aimed to examine the associations between BMI, cognitive function, and all-cause mortality, including between-factor interactions, in the general population of older adults in China.

METHODS

We used the data between 2011 and 2018 from the Chinese Longitudinal Healthy Longevity Survey that included adults aged ≥65 years residing in the 23 provinces of China. The association between BMI and cognitive function on all-cause mortality was examined with the Cox proportional hazards regression model.

RESULTS

The study included 8,293 Chinese older adults. Low BMI (underweight) and cognitive impairment were associated with the highest risk of death after adjustments [hazard ratio (HR) = 2.18; 95% confidence interval (CI), 1.96-2.41]; this combined effect was more prominent among adults aged <100 years and women. In addition, there was an interaction effect of BMI and cognitive impairment on all-cause mortality (P <0.001). Concurrently, among older adults with normal cognition, the risk of mortality related to underweight was higher than among their cognitively impaired counterparts [55% (normal cognition) vs. 38% (cognitive impairment)].

CONCLUSIONS

Low BMI (underweight) and cognitive impairment were independently and jointly associated with increased risk of all-cause mortality among Chinese older adults, and females showed a stronger effect in this association. The association between BMI and mortality was more pronounced in the participants with normal cognition than in their cognitively impaired counterparts.

Relationship Between Metabolic Syndrome and Cognitive Function: A Population-Based Study of Middle-Aged and Elderly Adults in Rural China

INTRODUCTION

To explore the relationship between metabolic syndrome (MetS) and cognitive impairment in a low-income and low-education population.

METHODS

All residents aged ≥45 years in a low-income population in Tianjin, China, were eligible to participate in this study. The Mini-Mental State Examination (MMSE) scale was used to conduct a preliminary screening and assessment of the participants' cognitive statuses. The MMSE components are orientation, registration, attention and calculation, recall, and language.

RESULTS

In this population, the prevalences of MetS and cognitive impairment were 54.1% and 44.5%, respectively. In the overall population, the registration score was 0.105 points lower in the elevated triglycerides (TG) group than in the normal TG group (β, -0.105; 95% confidence interval [CI]: -0.201, -0.010; P=0.030). In men, high TG was associated with registration scores that were 0.152 points lower than those in the normal TG group (95% CI: -0.281, -0.022; P=0.022), while larger WC and lower HDL-C had positive effects on cognitive scores (all P<0.05). However, in women, there were no significant differences between cognitive scores and MetS or its components.

CONCLUSION

In this population, first, TG had a great impact on cognition, even greater than the impact of MetS on cognition. Second, the impact of MetS components on cognition was more obvious in men, and not all of the effects were negative. Therefore, the effect of MetS on cognition may need to be analyzed separately for different populations, and it may be that the effect of a single component is greater than the overall effect. When formulating prevention strategies for cognitive impairments, population differences must also be taken into consideration.

Body mass index and all-cause mortality in older adults: A scoping review of observational studies

In older age, body composition changes as fat mass increases and redistributes. Therefore, the current body mass index (BMI) classification may not accurately reflect risk in older adults (65+). This study aimed to review the evidence on the association between BMI and all-cause mortality in older adults and specifically, the findings regarding overweight and obese BMI. A systematic search of the OVID MEDLINE and Embase databases was conducted between 2013 and September 2018. Observational studies examining the association between BMI and all-cause mortality within a community-dwelling population aged 65+ were included. Seventy-one articles were included. Studies operationalized BMI categorically (n = 60), continuously (n = 8) or as a numerical change/group transition (n = 7). Reduced risk of mortality was observed for the overweight BMI class compared with the normal BMI class (hazard ratios [HR] ranged 0.41-0.96) and for class 1 or 2 obesity in some studies. Among studies examining BMI change, increases in BMI demonstrated lower mortality risks compared with decreases in BMI (HR: 0.83-0.95). Overweight BMI classification or a higher BMI value may be protective with regard to all-cause mortality, relative to normal BMI, in older adults. These findings demonstrate the potential need for age-specific BMI cut-points in older adults.

Association between biomass fuel use and risk of hypertension among Chinese older people: A cohort study

BACKGROUNDS

Previous studies linking biomass fuel use to hypertension have been inconsistent. We investigated the association between biomass fuel use and the risk of hypertension and blood pressure measures in older Chinese people.

METHODS

The prospective cohort study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) included participants aged 65 years and older in 2011/2012 who were followed up until 2014 in 23 provinces in China. We explored the association between biomass fuel use and hypertension using the Cox proportional hazards model and examined the relationship of biomass fuel use with blood pressure measures using the generalized estimating equation. Additionally, we examined the effect of switching cooking fuels on hypertension during the follow-up.

RESULTS

Among 3754 participants who were without hypertension at baseline, the mean age was 86 years old, and 47.5% of participants were men. Reported use of biomass fuel for cooking (50.2%) was associated with a higher risk of hypertension (incidence rate (IR) per 100 person-years: 13.15 versus 12.99, hazard ratio (HR) = 1.15, 95% confidence interval (CI) = 1.01-1.31). Biomass fuel use was related to systolic blood pressure (SBP) (β 1.10 mmHg, 95% CI: 0.48-1.72), diastolic blood pressure (DBP) (β 1.02 mmHg, 95% CI: 0.61-1.43) and mean arterial pressure (MAP) (β 1.03 mmHg, 95% CI: 0.63-1.43) elevation. Compared with persistent clean fuel users, participants who reported switching from clean to biomass fuels for cooking had a noticeably higher risk of hypertension (IR per 100 person-years: 14.27 versus 12.81, HR 1.49, 95% CI: 1.16-1.90) and higher SBP (3.71 mmHg), DBP (2.44 mmHg) and MAP (2.86 mmHg). Interaction and stratified analyses showed greater effect estimates of SBP and MAP in the oldest oldpeople (≥85).

CONCLUSIONS

The use of biomass fuel for cooking was associated with greater hypertension risk, and the risk may be higher among those who switched from clean fuels to biomass fuels in the Chinese elderly population. Biomass fuel use was associated with a statistically significant but small absolute increase in blood pressure measures.

Sensory Impairment and All-Cause Mortality Among the Oldest-Old: Findings from the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

OBJECTIVES

To investigate the association between sensory impairment and all-cause mortality among the oldest-old (aged 80 and older) in China.

DESIGN

Prospective cohort study.

SETTING

Community-based setting in 22 provinces of China.

PARTICIPANTS

A total of 8788 older adults aged 80 and over at baseline with complete hearing and vision function data were included as the study population.

MEASUREMENTS

Sensory impairment was categorized as no sensory impairment, hearing impairment (HI) only, vision impairment (VI) only and dual sensory impairment (DSI) according to hearing and vision function. Deaths were identified through interviews by close family members. Cox proportion hazards regression models were used to examine the association of sensory impairment with mortality, adjusting for socio-demographic data, life style factors and health status.

RESULTS

The mean age was 92.3 ± 7.6 years old, and 60.1% of participants were female. Among 8788 participants, 9.8% were recognized as DSI, 9.7% were HI only and 10.4% with VI only. Comparing with participants with no sensory impairment, those with VI only (HR=1.10, 95% CI=1.01-1.20) and DSI (HR=1.21, 95% CI=1.09-1.35) were significantly associated with higher risk of all-cause mortality in the fully adjusted model.

CONCLUSION

Our results demonstrated that VI only and DSI were significantly associated with higher risk of mortality among Chinese older adults aged 80 and over. The finding advocated that it is necessary to identify and manage sensory impairments for the advanced ages to reduce mortality risks.

Cognitive decline and mortality among community-dwelling Chinese older people

BACKGROUND

Whether cognitive decline is related to a higher risk of death independent of the initial cognitive function is inconclusive. Evidence of the association between cognitive decline and mortality among Chinese older people is limited. We aimed to examine whether cognitive decline, assessed by the rate of decrease in the Mini-Mental State Examination (MMSE) score, was associated with mortality independent of initial cognitive function (baseline MMSE score) among Chinese older people.

METHODS

We established two successive and non-overlapping cohorts of older adults nested within the Chinese Longitudinal Healthy Longevity Survey (CLHLS), an ongoing, open, community-based cohort survey conducted every 2-3 years. Cognitive function was measured using the Chinese version of the MMSE. A total of 11,732 older adults who completed two consecutive cognitive function examinations were included and followed for 3 years. A Cox proportional hazards model was used to examine the association of cognitive decline with mortality after adjusting for sociodemographic characteristics, health behaviours, comorbidities and initial cognitive function.

RESULTS

The mean age was 82.5 years old, and 44.9% (5264/11732) of participants were men. After adjusting for baseline MMSE scores and other covariates, the rate of change in MMSE scores over 3 years was monotonically and positively associated with subsequent 3-year mortality. Compared to those with stable cognitive function, participants with rapid cognitive decline (decline faster than average, a reduction of MMSE scores > 1.62 points/year) had a 75% higher risk of death (hazard ratio = 1.75, 95% confidence interval 1.57-1.95). The association between cognitive decline and mortality was stronger among relatively younger Chinese older people (aged 65-79 years versus 80 years and over) and those with normal cognitive function at baseline (MMSE scores ≥ 24 versus < 24 points), respectively, but did not differ by cohort and sex.

CONCLUSION

Faster cognitive decline was associated with higher mortality independent of initial cognitive function, especially among those aged 65-79 years and those with normal cognitive function at baseline. The association was consistent across two successive cohorts. Our findings indicate the practical significance of monitoring cognitive change in older adults.