Age and gender differences in the association between body mass index and all-cause mortality among older Japanese

Predictive value of the random forest model based on bioelectrical impedance analysis parameter trajectories for short-term prognosis in stroke patients

BACKGROUND

The short-term prognosis of stroke patients is mainly influenced by the severity of the primary disease at admission and the trend of disease development during the acute phase (1-7 days after admission).

OBJECTIVE

The aim of this study is to explore the relationship between the bioelectrical impedance analysis (BIA) parameter trajectories during the acute phase of stroke patients and their short-term prognosis, and to investigate the predictive value of the prediction model constructed using BIA parameter trajectories and clinical indicators at admission for short-term prognosis in stroke patients.

METHODS

A total of 162 stroke patients were prospectively enrolled, and their clinical indicators at admission and BIA parameters during the first 1-7 days of admission were collected. A Group-Based Trajectory Model (GBTM) was employed to identify different subgroups of longitudinal trajectories of BIA parameters during the first 1-7 days of admission in stroke patients. The random forest algorithm was applied to screen BIA parameter trajectories and clinical indicators with predictive value, construct prediction models, and perform model comparisons. The outcome measure was the Modified Rankin Scale (mRS) score at discharge.

RESULTS

PA in BIA parameters can be divided into four separate trajectory groups. The incidence of poor prognosis (mRS: 4-6) at discharge was significantly higher in the "Low PA Rapid Decline Group" (85.0%) than in the "High PA Stable Group " (33.3%) and in the "Medium PA Slow Decline Group "(29.5%) (all P < 0.05). In-hospital mortality was the highest in the "Low PA Rapid Decline Group" (60%) compared with the remaining trajectory groups (P < 0.05). Compared with the prediction model with only clinical indicators (Model 1), the prediction model with PA trajectories (Model 2) demonstrated higher predictive accuracy and efficacy. The area under the receiver operating characteristic curve (AUC) of Model 2 was 0.909 [95% CI 0.863, 0.956], integrated discrimination improvement index (IDI), 0.035 (P < 0.001), and net reclassification improvement (NRI), 0.175 (P = 0.031).

CONCLUSION

PA trajectories during the first 1-7 days of admission are associated with the short-term prognosis of stroke patients. PA trajectories have additional value in predicting the short-term prognosis of stroke patients.

Fast walking and physical activity are independent contributors to improved physical function

BACKGROUND AND OBJECTIVES

To clarify whether the presence or absence of fast walking and habitual physical activity are independently associated with the incidence of functional disability.

METHODS

This historical cohort study was comprised of 9,652 (4,412 men, mean age 65 years) individuals aged 39-98 years without functional disability at baseline. Functional disability was determined based on the Japanese long-term care insurance system, which specified requirements for assistance in the activities of daily living. The impact of fast walking and habitual physical activity on the incidence of functional disability was analysed by Cox proportional hazards models.

RESULTS

The follow-up period was a median of 3.7 years during which 165 patients were newly certified as having functional disability. In the multivariate analysis, baseline age in 5-year increments (hazard ratio 2.42 [95% confidence interval 2.18-2.69]), no habitual physical activity (1.56 [1.07-2.27]), and not fast walking (1.89 [1.32-2.69]) significantly increased the risk of functional disability after adjustment for covariates. The stratified analysis showed that compared with physical activity (+), the impact of physical activity (-) on the incidence of functional disability was observed in those aged ≥75 years regardless of fast walking (+). Fast walking (-) significantly increased the risk of disability compared with fast walking (+) in those aged <75 years regardless of a physical activity habit.

CONCLUSION

In Japanese, slow walking speed and lack of a physical activity habit were shown to be independent risk factors for incident functional disability, with their impact differing according to age.

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.

Inverse association between body mass index and all-cause mortality in rural chinese adults: 15-year follow-up of the Anqing cohort study

OBJECTIVE

To investigate the association between body mass index (BMI) and all-cause mortality in a Chinese rural population.

DESIGN

Prospective cohort study.

SETTING

This study was conducted from 2003 to 2018 in Anqing, Anhui Province, China.

PARTICIPANTS

17 851 participants aged 25-64 years (49.4% female) attending physical examinations and questionnaire were included in this study. The inclusion criterion was families having a minimum of three participating siblings. The exclusion criteria included participants without family number and BMI data at baseline.

OUTCOME MEASURES

The outcome measure was all-cause mortality. Generalized estimating equation (GEE) regression analysis was performed to determine the association between baseline BMI and all-cause mortality.

RESULTS

During a mean follow-up period of 14.1 years, 730 deaths (8.0%) occurred among men, and 321 deaths (3.6%) occurred among women. The mean BMI for males was 21.3[Formula: see text] kg/m², and for female it was 22.1±3.1 kg/m². Baseline BMI was significantly inversely associated with all-cause mortality risk for per SD increase (OR, 0.79 (95% CI, 0.72 to 0.87) for males; OR, 0.88 (95% CI, 0.76 to 1.01) for females). When BMI was stratified with cut points at 20 and 24 kg/m², compared with the low BMI group, a significantly lower risk of death was found in the high BMI group (BMI ≥24: OR, 0.57 (95% CI, 0.43 to 0.77) in males; 0.65 (95% CI, 0.46 to 0.93) in females) after adjustment for relevant factors.

CONCLUSIONS

In this relatively lean rural Chinese population, the risk of all-cause mortality decreased with increasing BMI. The excess risk of all-cause mortality associated with a high BMI was not seen among this rural population.

Factors Associated with Denture Non-use in Older Adults Requiring Long-Term Care

BACKGROUND

Evidence suggests that denture non-use is significantly associated with activities of daily living, oral function, and cognitive decline. Few studies have focused on the possibility that the indications for denture use may differ depending on the cognitive and physical functions in older adults requiring long-term care.

OBJECTIVES

The aim of this study was to elucidate the factors associated with denture non-use in older adults requiring long-term care.

METHODS

This cross-sectional study comprised 201 older adults (45 men and 156 women; average age = 86.2 ± 7.1 years) requiring long-term care in Japan. Those who did not require denture treatment were classified by dentists into denture-use and denture non-use groups. The severity of dementia was assessed using the Clinical Dementia Rating scale. Multiple logistic regression analyses were conducted to detect the factors significantly associated with denture non-use.

RESULTS

The proportion of participants without dentures was 58.2%. Multiple logistic regression analyses revealed that a moderate dementia (odds ratio [OR], 4.44; 95% confidence interval [CI] 1.18-16.71, p=0.027) and rinsing ability (OR 3.00; 95% CI 1.12-8.06; p=0.030) were significant factors related to the non-use of dentures.

CONCLUSION

Severity of dementia and rinsing ability were significantly associated with non-use of dentures. These findings indicate the necessity of evaluating oral and cognitive functions while planning denture treatment in older adults requiring long-term care.

The Clinical Characteristics of Acute Pancreatitis in Gerontal Patients: A Retrospective Study

Background

The incidence of acute pancreatitis (AP) in ageing patients has increased in recent years, and results regarding the clinical outcomes of these patients are controversial. The aim of this study was to compare the clinical outcomes of AP in ageing patients over 60 years old.

Methods

Eighty patients aged ≥80 years (oldest group) were compared to 393 patients aged 60 to 79 years (older group). The clinical course and biochemical and radiological data were evaluated. The primary endpoints were mortality rate, intensive care unit (ICU) admission rate and in-hospital length of stay (LOS). The secondary endpoints were the incidence of operative treatment and complications of AP.

Results

Abdominal pain (61.3% vs 46.3%, P=0.013) was less common in the oldest group. Jaundice (17.5% vs 8.9%, P=0.021) and dyspnoea (26.3% vs 11.5%, P=0.001) were more obvious in the oldest group than in the older group. The mean BMI was lower in the oldest group than in the older group (21.07±3.18 vs 22.36±2.89, P = 0.001). Age over 80 years (P=0.011) and organ failure (P<0.05) were independent risk factors for mortality. More severe AP (P=0.001), abdominal pain (P=0.033) and organ failure (P<0.05) were associated with the ICU admission rate. Age over 80 years (P=0.001), more severe AP (P=0.001), female sex (P=0.018), jaundice (P=0.038), operative treatment (P<0.05) and organ failure (P<0.05) were risk factors for increased LOS.

Conclusion

The oldest group had a higher death rate and longer LOS than the older group. More attention should be given to the clinical symptoms of this frail population. We propose that more comprehensive and goal-directed attendant diagnostic procedures should be performed to detect the disease early and to improve the outcomes of ageing patients.