Physical Health Indicators Improve Prediction of Cardiovascular and All-cause Mortality among Middle-Aged and Older People: a National Population-based Study

Development and validation of questionnaire-based machine learning models for predicting all-cause mortality in a representative population of China

Background

Considering that the previously developed mortality prediction models have limited applications to the Chinese population, a questionnaire-based prediction model is of great importance for its accuracy and convenience in clinical practice.

Methods

Two national cohort, namely, the China Health and Nutrition Survey (8,355 individual older than 18) and the China Health and Retirement Longitudinal Study (12,711 individuals older than 45) were used for model development and validation. One hundred and fifty-nine variables were compiled to generate predictions. The Cox regression model and six machine learning (ML) models were used to predict all-cause mortality. Finally, a simple questionnaire-based ML prediction model was developed using the best algorithm and validated.

Results

In the internal validation set, all the ML models performed better than the traditional Cox model in predicting 6-year mortality and the random survival forest (RSF) model performed best. The questionnaire-based ML model, which only included 20 variables, achieved a C-index of 0.86 (95%CI: 0.80-0.92). On external validation, the simple questionnaire-based model achieved a C-index of 0.82 (95%CI: 0.77-0.87), 0.77 (95%CI: 0.75-0.79), and 0.79 (95%CI: 0.77-0.81), respectively, in predicting 2-, 9-, and 11-year mortality.

Conclusions

In this prospective population-based study, a model based on the RSF analysis performed best among all models. Furthermore, there was no significant difference between the prediction performance of the questionnaire-based ML model, which only included 20 variables, and that of the model with all variables (including laboratory variables). The simple questionnaire-based ML prediction model, which needs to be further explored, is of great importance for its accuracy and suitability to the Chinese general population.

Predictive Validity of Motor Fitness and Flexibility Tests in Adults and Older Adults: A Systematic Review

Motor fitness and flexibility have been linked to several health issues. We aimed to investigate the predictive validity of motor fitness and flexibility tests in relation to health outcomes in adults and older adults. Web of Science and PubMed databases were screened for studies published from inception to November 2020. Two authors systematically searched, evaluated, and extracted data from identified original studies and systematic reviews/meta-analysis. Three levels of evidence were constructed: strong, moderate, and limited/inconclusive evidence. In total, 1182 studies were identified, and 70 studies and 6 systematic reviews/meta-analysis were summarized. Strong evidence indicated that (i) slower gait speed predicts falls and institutionalization/hospitalization in adults over 60 years old, cognitive decline/impairment over 55 years old, mobility disability over 50 years old, disability in instrumental activities of daily living (IADL) over 54 years old, cardiovascular disease risk over 45 years old, and all-cause mortality over 35 years old; (ii) impaired balance predicts falls and disability in IADL/mobility disability in adults over 40 years old and all-cause mortality over 53 years old; (iii) worse timed up&go test (TUG) predicts falls and fear of falling over 40 years old. Evidence supports that slower gait speed, impaired balance, and worse TUG performance are significantly associated with an increased risk of adverse health outcomes in adults.

Adding Estimated Cardiorespiratory Fitness to the Framingham Risk Score and Mortality Risk in a Korean Population-Based Cohort Study

BACKGROUND

The added value of non-exercise-based estimation of cardiorespiratory fitness (eCRF) to cardiovascular disease (CVD) risk factors for mortality risk has not been examined in Korean populations.

METHODS

This population-based prospective cohort study examined the relationship of the 10-year Framingham risk score (FRS) for CVD risk and eCRF with all-cause and CVD mortality in a representative sample of Korean adults aged 30 years and older. Data regarding a total of 38,350 participants (16,505 men/21,845 women) were obtained from the 2007-2015 Korea National Health and Nutrition Examination Survey (KNHANES). All-cause and CVD mortality were the main outcomes. The 10-year FRS point sum and eCRF level were the main exposures.

RESULTS

All-cause and CVD mortality was positively correlated with the 10-year FRS point summation and inversely correlated with eCRF level in this study population. The protective of high eCRF against all-cause and CVD mortality was more prominent in the middle and high FRS category than in the low FRS category. Notably, the FRS plus eCRF model has better predictor power for estimating mortality risk compared to the FRS only model.

CONCLUSIONS

The current findings indicate that eCRF can be used as an alternative to objectively measured CRF for mortality risk prediction.

Association between Relative Handgrip Strength and Dyslipidemia in Korean Adults: Findings of the 2014-2015 Korea National Health and Nutrition Examination Survey

BACKGROUND

Grip strength is a convenient method to measure muscle strength. Recently, relative handgrip strength (HGS) was recommended as a clinical predictor of metabolic health and disease, such as dyslipidemia, which is considered a risk factor for cardiovascular disease. The purpose of this study was to characterize the association between relative HGS and dyslipidemia.

METHODS

We included 6,027 adults (2,934 men, 3,093 women) aged 30-69 years who participated in the Korea National Health and Nutrition Examination Survey in 2014 and 2015. Relative HGS was obtained by dividing the HGS by body mass index. Complex sampling analysis was conducted to compare the general characteristics of participants according to the quartiles of relative HGS. Logistic regression analysis was used to examine the association between quartiles of relative HGS and dyslipidemia.

RESULTS

After adjustment for age, prevalence of diabetes mellitus, prevalence of hypertension, alcohol consumption, smoking status, exercise, income, and education level, relative HGS was inversely associated with dyslipidemia in both men and women. In multivariable logistic regression analysis, the odds ratios (95% confidence intervals) for dyslipidemia in quartiles 1, 2, and 3 relative to quartile 4 were 1.36 (1.00-1.83), 1.29 (0.98-1.70), 1.23 (0.95- 1.60) in men and 1.81 (1.30-2.50), 1.81 (1.32-2.47), 1.39 (1.07-1.81) in women, respectively.

CONCLUSION

Relative HGS was inversely associated with dyslipidemia risk in Korean adults. Muscle-strengthening exercise is recommended to enhance health outcomes.

Derivation and validation of 10-year all-cause and cardiovascular disease mortality prediction model for middle-aged and elderly community-dwelling adults in Taiwan

Prediction model mainly focused on specific diseases, such as diabetes, hypertension, cardiovascular disease, or patients with cancer, or populations of Europe and America, thereby limiting its generalization. This study aimed to develop and validate a 10-year mortality risk score by using data from a population-representative sample of adults. Data were collected from 2,221 Taichung Community Health study participants aged ≥40 years. The baseline period of the study was 2004, and all participants were followed up until death or in 2016. Cox’s proportional hazards regression analyses were used to develop the prediction model. A total of 262 deaths were ascertained during the 10-year follow-up. The all-cause mortality prediction model calculated the significant risk factors, namely, age, sex, marital status, physical activity, tobacco use, estimated glomerular filtration rate, and albumin-to-creatinine ratio, among the baseline risk factors. The expanded cardiovascular disease (CVD) mortality prediction model consisted of six variables: age, sex, body mass index, heart disease plus heart disease medication use, stroke plus medication use, and ankle–brachial index. The areas under receiver operating curves of the 3-, 5- and 10-year predictive models varied between 0.97, 0.96, and 0.88 for all-cause mortality, and between 0.97, 0.98, and 0.84 for expanded CVD mortality. These mortality prediction models are valid and can be used as tools to identify the increased risk for mortality.

PM2.5 air pollution contributes to the burden of frailty

Frailty is common among older people and results in adverse health outcomes. We investigated whether exposure to PM_2.5 is associated with frailty. This cross-sectional study involved 20,606 community-dwelling participants aged ≥ 65 years, residing in New Taipei City, Taiwan. Analytic data included phenotypic frailty, disease burden by Charlson Comorbidity Index (CCI), urban or rural residence, and household income. PM_2.5 exposure was calculated from air quality monitoring records, with low exposure defined as the lowest quartile of the study population. 1,080 frail participants (5.2%) were older, predominantly female, had more comorbidities, lived rurally, and had low PM_2.5 exposure (all p < 0.001). In multinomial logistic regression analyses, the likelihood of high PM_2.5 exposure was higher in prefrail (OR 1.4, 95% CI 1.3–1.5) and frail adults (OR 1.5, 95% CI 1.2–1.9) than in robust individuals, with stronger associations in those who were male (frail: OR 2.1, 95% CI 1.5–3.1; prefrail: OR 2.2, 95% CI 1.9–2.6), ≥ 75 years old (frail: OR 1.8, 95% CI 1.3–2.4; prefrail: OR 1.5, 95% CI 1.3–1.8), non-smokers (frail: OR 1.6, 95% CI 1.3–2.0; prefrail: OR 1.4, 95% CI 1.2–1.5), had CCI ≥ 2 (frail: OR 5.1, 95% CI 2.1–12.6; prefrail: OR 2.1, 95% CI 1.2–3.8), and with low household income (frail: OR 4.0, 95% CI 2.8–5.8; prefrail: OR 2.7, 95% CI 2.2–3.3). This study revealed a significant association between PM_2.5 exposure and frailty, with a stronger effect in vulnerable groups.

Effect of relative handgrip strength on cardiovascular disease among Korean adults aged 45 years and older: Results from the Korean Longitudinal Study of Aging (2006-2016)

BACKGROUND

Aging causes both structural and functional changes in the skeletal muscle, and is associated with changes in body composition form, which results in an increased incidence of cardiovascular death. Handgrip strength (HGS) is a simple, fast, reliable, and cost-effective tool for measuring muscle strength.

OBJECTIVE

We aimed to investigate which index was most suitable for predicting cardiovascular disease (CVD), and suggested the optimal cut-off points based on the handgrip strength index. In addition, we aimed to identify the effects of weak HGS, as determined by applying the optimal cut point on the occurrence of CVD.

METHOD

A total of 8494 older men and women aged over 45 years from the Korean Longitudinal Study of Aging (KLoSA) were included in this study at baseline. We performed general estimating equations (GEE) with independent correlation structure to assess whether handgrip strength is longitudinally related to occurrence of CVDs such as heart disease or stroke reported from 1 st to 6th wave of KLoSA.

RESULTS

The relative HGS was strongly associated with CVD in both sexes, and the best fit model was in that in comparison to dominant HGS and absolute HGS. In addition, we calculated the optimal cut point for CVD based on the relative HGS in this study (men: 2.52 and women: 1.55, respectively), and demonstrated that low HGS, as determined by applying relative HGS cut points, was associated with a higher OR for CVD compared to normal HGS; the associations observed were consistent between the sexes.

CONCLUSIONS

Our findings suggest that HGS has the potential to be a valuable screening tool for cardiovascular risk in clinical settings; this is advantageous in situations where blood sampling is not possible since HGS is easily measured and highly reproducible. It is necessary to pay attention to weak grip strength against body size in the elderly population.

Relationship between peak expiratory flow and incidence of frailty, deaths and falls among nursing home residents: Results of the SENIOR cohort

OBJECTIVE

To correlate peak expiratory flow (PEF) with the incidence of frailty, deaths and falls among nursing home residents.

METHODS

This is a 1-year longitudinal analysis performed on the clinical data of the SENIOR cohort. PEF, measured by peak flow meter, was considered as "low" when the observed value was ≤80% of the theoretical value. Physical capacity was evaluated using Short Physical Performance Battery, balance and gait using Tinetti test and muscle strength using a dynamometer. The incidence of frailty was defined as the transition from a "robust" or "prefrail" status to a "frail" status following Fried's criteria. Deaths and falls were also collected.

RESULTS

Among 646 subjects included at baseline (83.2 ± 9 years and 72.1% women), 297 (45.7%) displayed a low PEF. In this subgroup, physical capacity (p-values from 0.01 to <0.001), muscle strength (p < 0.001), balance and gait score (p < 0.001) were significantly lower compared to subjects displaying normal PEF. Subjects who became frail after one year displayed a lower % of the theoretical PEF value compared to those that did not (88.52 ± 45.06 vs 102.78 ± 50.29, respectively, p = 0.03). After adjustment for potential confounding variables (calf circumference, Tinetti test, SPPB test and handgrip strength), PEF was no longer associated with the occurrence of frailty. There was no association between PEF and mortality and falls.

CONCLUSION

In a nursing home setting, PEF is not an independent factor associated with the incidence of frailty, deaths and falls.

Relative handgrip strength in relation to depressive mood and suicidal ideation in Koreans using the 2015 KNHANES data

OBJECTIVES

This study aimed to examine the association of relative handgrip strength (RHGS) with depressive mood and suicidal ideation.

METHODS

A cross-sectional study was conducted among 2167 men and 2643 women (aged 50.9 years ± 16.7 years) who participated in the 2015 Korean National Health and Nutrition Examination Survey. RHGS was defined by the handgrip strength/body mass index (BMI) ratio. Depressive mood and suicidal ideation were assessed using self-reported questionnaires. Logistic regression analysis was conducted after adjusting for sex, concurrent illness, age, education, income, smoking status, alcohol use, physical activity, and depressive mood (in the analysis for suicidal ideation).

RESULTS

Among participants, 4.0% men and 5.7% women reported serious suicidal ideation while 9.5% men and 16.0% women reported serious depressive mood. After adjusting for confounding factors, RHGS was associated with depressive mood (odds ratio [95% confidence interval] per RHGS [kg/BMI], 0.82 [0.69-0.99]) and suicidal ideation (0.73 [0.54-0.99]). In sex-specific relationship, RHGS was associated with depressive mood and suicidal ideation in women (0.71 [0.55-0.93] and 0.54 [0.34-0.85], respectively) but not in men.

CONCLUSIONS

Poorer RHGS indicates higher risk of depressive mood as well as suicidal ideation regardless of depressive mood among women.

Relationship Between Handgrip Strength and Nonalcoholic Fatty Liver Disease: Nationwide Surveys

BACKGROUND

The association of handgrip strength with nonalcoholic fatty liver disease (NAFLD) has not been studied yet. This study investigated the relationship between handgrip strength and NAFLD in South Korean adults.

METHODS

Referring to the Korea National Health and Nutrition Examination Survey 2014 and 2015 database, South Korean adults (n = 8001, women: 55.5%) aged 19-80 years having complete data were considered for this study. Relative handgrip strength (RHGS) [average handgrip strength of both hands divided by body mass index (BMI)], hepatic steatosis index (HSI), BMI, and components of metabolic syndrome were measured. Demographics, treatment of concurrent illnesses, and health-related behaviors were assessed by using standardized questionnaires. NAFLD was defined by the HSI >36.0, alcohol consumption <20 grams/day, and negative biomarkers for chronic hepatitis B and C.

RESULTS

The prevalence of NAFLD was 30.3% ± 0.7%. Complex sample logistic regression analysis revealed that individuals with lower RHGS [per 1 standard deviation (SD) decrease] manifested higher odds of suffering from NAFLD (adjusted odds ratio: 1.47, 95% confidence interval: 1.35-1.60). Furthermore, lower RHGS was associated with higher odds for NAFLD throughout the strata of sex, age group, education, BMI category, metabolic syndrome, treatment history of illnesses, smoking status, alcohol consumption, or physical activity. The odds for NAFLD increased in the range of 1.40-1.63 with 1 SD decrease in RHGS according to the strata.

CONCLUSIONS

This study of South Korean adults suggests that lower handgrip strength is associated with NAFLD regardless of sociodemographic characteristics, weight status, metabolic syndrome, concurrent illnesses, and lifestyle.

Cognitive frailty predicting all-cause mortality among community-living older adults in Taiwan: A 4-year nationwide population-based cohort study

BACKGROUND

Cognitive frailty (CF) featured as frailty plus cognitive impairment was deemed to be a novel target for dementia and disable prevention. The study was intended to investigate the epidemiology of CF and the association between CF and all-cause mortality.

METHODS

The national representative cohort study was comprised of 1,103 community-living middle-aged and older adults. CF was defined as the co-existence of dynapenia (weakness and/or slowness) and cognitive impairment (1.5 standard deviations below the age-, sex- and education-matched norms in cognitive tests) without known neurodegenerative diseases. Dynapenia was defined by the Asian Working Group for Sarcopenia and cognitive function was assessed by the Short Portable Mental Status Questionnaire.

RESULTS

The prevalence of CF was 8.6% in this study. Subjects with CF were older, more likely to be women, having less regular exercise, fewer educational years, more depressive symptoms and greater multimorbidity. Compared to robust individuals, CF was significantly associated with all-cause mortality (HR: 3.1, 95% CI:1.3-7.7, p = 0.012).

CONCLUSION

Dynapenia and cognitive impairment synergistically contribute to the mortality risk for the participants in this study. Further study is needed to explore the underlying pathophysiology and the reversibility of CF.

Dysmobility Syndrome and Risk of Mortality for Community-Dwelling Middle-Aged and Older Adults: The Nexus of Aging and Body Composition

Dysmobility syndrome is a newly proposed concept to comprehensively consider bone-muscle-adiposity as a whole to associate with mortality and other adverse outcomes in the older adults. Little was known in Asian populations since the body composition was highly related to ethnicity. The study aimed to evaluate the association between dysmobility syndrome and mortality and to explore the most optimal operational definition for dysmobility syndrome. The prevalence of dysmobility syndrome was 3.9–10.1% based on different operational definitions of adiposity and skeletal muscle index. Subjects with dysmobility syndrome were older, more often to be women, having higher adiposity, lower lean body mass and bone mineral density. Multivariate Cox proportional hazard model showed that dysmobility and pre-dysmobility syndrome had higher risk of mortality than the robust group (Hazard ratio (HR): 11.3, 95% confidence interval (CI): 1.2–109.1; and HR 8.7, 95% CI 1.1-67.3, respectively). Overall, the modified operational definition of dysmobility syndrome in Asian populations using FNIH-adjusted skeletal muscle mass and waist circumference-defined adiposity may be the most optimal model for mortality prediction. Taking the nexus of body composition as a whole to evaluate the mortality risk of older adults is an important improvement beyond sarcopenia and osteoporosis.