Develop and Validate a Prognostic Index With Laboratory Tests to Predict Mortality in Middle-Aged and Older Adults Using Machine Learning Models: A Prospective Cohort Study.

BACKGROUND: Prognostic indices can enhance personalized predictions of health burdens. However, a simple, practical, and reproducible tool is lacking for clinical use. This study aimed to develop a machine learning-based prognostic index for predicting all-cause mortality in community-dwelling older individuals. METHODS: We utilized the Healthy Aging Longitudinal Study in Taiwan (HALST) cohort, encompassing data from 5 663 participants. Over the 5-year follow-up, 447 deaths were confirmed. A machine learning-based routine blood examination prognostic index (MARBE-PI) was developed using common laboratory tests based on machine learning techniques. Participants were grouped into multiple risk categories by stratum-specific likelihood ratio analysis based on their MARBE-PI scores. The MARBE-PI was subsequently externally validated with an independent population-based cohort from Japan. RESULTS: Beyond age, sex, education level, and BMI, 6 laboratory tests (low-density lipoprotein, albumin, aspartate aminotransferase, lymphocyte count, high-sensitivity C-reactive protein, and creatinine) emerged as pivotal predictors via stepwise logistic regression (LR) for 5-year mortality. The area under curves of MARBE-PI constructed by LR were 0.799 (95% confidence interval [95% CI]: 0.778-0.819) and 0.756 (95% CI: 0.694-0.814) for the internal and external validation data sets, and were 0.801 (95% CI: 0.790-0.811) and 0.809 (95% CI: 0.774-0.845) for the extended 10-year mortality in both data sets, respectively. Risk categories stratified by MARBE-PI showed a consistent dose-response association with mortality. The MARBE-PI also performed comparably with indices constructed with clinical health deficits and/or laboratory results. CONCLUSIONS: The MARBE-PI is considered the most applicable measure for risk stratification in busy clinical settings. It holds potential to pinpoint older individuals at elevated mortality risk, thereby aiding clinical decision-making.

Impact of physical activity on disability-free and disabled life expectancies in middle-aged and older adults: Data from the healthy aging longitudinal study in Taiwan.

AIM: Leisure-time physical activity (LTPA) promotes healthy aging; however, data on work-related physical activity (WPA) are inconsistent. This study was conducted to examine the disability-free life expectancy (DFLE) and disabled life expectancy (DLE) across physical activity levels, with a focus on WPA, in middle-aged and older adults. METHODS: Data from 5663 community-dwelling participants aged ≥55 years and enrolled in the Healthy Aging Longitudinal Study in Taiwan were evaluated. Energy expenditures from LTPA and WPA were calculated from baseline questionnaires and categorized into sex-specific cutoffs. Disability was based on repeat measures of participants' activities of daily living and instrumental activities of daily living. Mortality was confirmed via data linkage with the Death Certificate database. DFLE and DLE were estimated from discrete-time multistate life-table models. RESULTS: At age 65, women with low WPA had a DLE of 2.88 years (95% confidence interval [CI], 1.67-4.08), which was shorter than that of women without WPA (DLE, 5.24 years; 95% CI, 4.65-5.83) and with high WPA (DLE, 4.01 years; 95% CI, 2.69-5.34). DFLE and DLE were similar across WPA levels in men. DFLE tended to increase as the LTPA increased in men and women. CONCLUSION: Women with low WPA had shorter DLE than did those with no or high WPA. To reduce the risks of disability associated with physical activity, public policy should advocate for older people to watch the type, amount, and intensity of their activities as these may go ignored during WPA. Geriatr Gerontol Int 2024; 24: 229-239.

Association of leukocyte mitochondrial DNA copy number with longitudinal C-reactive protein levels and survival in older adults: a cohort study.

BACKGROUND: Systemic chronic inflammation occurs with age. The association of the leukocyte mitochondrial DNA copy number, a measure of mitochondrial function in aging, with the temporal profile of serum high-sensitivity C-reactive protein and mortality risk remains uncertain. The objectives of this study were to examine the association of the leukocyte mitochondrial DNA copy number with longitudinal high-sensitivity C-reactive protein levels and the association of the longitudinal high-sensitivity C-reactive protein levels with mortality risk. METHODS: This prospective cohort study included 3928 adults aged ≥ 55 years without systemic inflammation in the baseline examination of the Healthy Aging Longitudinal Study in Taiwan, which started in 2009. Each participant received leukocyte mitochondrial DNA copy number measurement using a fluorescence-based quantitative polymerase chain reaction at baseline, serum high-sensitivity C-reactive protein measurements at baseline and the follow-up examination five years later, and the ascertainment of all-cause death (until November 30, 2021). The relationships among the leukocyte mitochondrial DNA copy number, longitudinal serum high-sensitivity C-reactive protein levels, and time to all-cause mortality were examined using the joint longitudinal and survival modeling analysis. RESULTS: Of the 3928 participants (mean age: 69 years; 2060 [52%] were women), 837 (21%) died during follow-up. In the adjusted analysis, one standard deviation lower natural log-transformed baseline leukocyte mitochondrial DNA copy number was associated with an increase of 0.05 (95% confidence interval [CI], 0.02 to 0.08) standard deviation in serum high-sensitivity C-reactive protein in subsequent years. An increase of 1 standard deviation in instantaneous high-sensitivity C-reactive protein levels was associated with a hazard ratio (HR) for all-cause mortality of 1.22 (95% CI, 1.14 to 1.30). Similar results were obtained after further adjusting for baseline high-sensitivity C-reactive protein levels (HR [95% CI], 1.27 [1.16 to 1.38]) and after excluding those with serum high-sensitivity C-reactive protein above 10 mg/L (HR [95% CI], 1.21[1.11 to 1.31]) or 3 mg/L (HR [95% CI], 1.19 [1.06 to 1.31]) during follow-up. CONCLUSIONS: A lower leukocyte mitochondrial DNA copy number was associated with persistently higher high-sensitivity C-reactive protein levels. Moreover, these higher time-varying high-sensitivity C-reactive protein levels were instantaneously associated with a higher risk of death.

Differential relationship of uric acid to mortality and clinical biomarkers of aging according to grip strength in older adults: a cohort study.

Uric acid is both a pro-oxidant and antioxidant. We investigated serum uric acid's association with mortality and aging biomarkers in older adults with varying levels of grip strength. A total of 5329 community-dwelling adults aged ≥55 years underwent assessments of serum uric acid levels, grip strength, and biomarkers of diverse physiological systems. The primary outcome was all-cause mortality. We observed a significant (P < .001) interaction between uric acid levels and grip strength on all-cause mortality risk. Among participants with low grip strength, a nonlinear association (P for nonlinearity = .006) was observed between serum uric acid levels and mortality risk after multivariate adjustment. Compared with participants with neither extreme uric acid levels nor low grip strength, those with a combination of high serum uric acid and low grip strength exhibited greater risks of mortality (adjusted hazard ratio [aHR], 1.52; 95% confidence interval [CI], 1.15-2.02) and deviations in biomarkers of specific systems, so did those with a combination of low serum uric acid and low grip strength (aHR, 1.52; 95% CI, 1.13-2.05). In conclusion, there was a J-shaped association between serum uric acid and the risk of all-cause mortality in older adults. This was primarily true for those with low grip strength.

Comparisons of clinical impacts on individuals with Brugada electrocardiographic patterns defined by ISHNE criteria or EHRA/HRS/APHRS criteria: a nationwide community-based study.

INTRODUCTION: Identifying Brugada electrocardiographic pattern (BrP) early is crucial to prevent sudden cardiac death. Two different diagnostic criteria proposed by International Society for Holter and Noninvasive Electrocardiography (ISHNE) and Heart Rhythm Society/European Heart Rhythm Association/Asia-Pacific Heart Rhythm Society (HRS/EHRA/APHRS) were widely used in clinical practice. The difference in prevalence and prognosis of BrP by applying the two different criteria was never studied before. METHODS: This study was prospectively conducted in a nationwide large-scale stratified random sampling community-based cohort (HALST) from Han Chinese population in Taiwan from December 2008 to December 2012. We compared the prevalence and prognosis of BrP defined by the two diagnostic criteria. RESULTS: A total of 5214 adults were enrolled (2530 men) with mean age of 69.3 years. Four had spontaneous type 1 BrP (0.077%). By the HRS/EHRA/APHRS criteria, 68 individuals have type 2 BrP (1.30%) and 101 have type 3 BrP (1.94%) whereas by the ISHNE criteria, 46 individuals exhibited type 2 BrP (0.88%). When applying the ISHNE criteria, the number of individuals with BrP decreased by 71%. However, all-cause mortality and cardiovascular mortality were not different between individuals with or without BrP, irrespective of the criteria used. CONCLUSIONS: The two different criteria may impact the diagnostic yield of individuals with BrP, but do not affect the prognosis of the individuals with BrP. Key messages Comparing with the use of HRS/EHRA/APHRS criteria, the number of individuals with Brugada ECG patterns was decreased by 71% when applying the ISHNE criteria. The prognosis of individuals with Brugada ECG patterns defined by 2012 ISHNE or 2013 HRS/EHRA/APHRS criteria were not different.