Risk factors for cerebrovascular disease mortality among the elderly in Beijing: a competing risk analysis

Cerebrovascular risk factors and their time-dependent effects on stroke survival in the EMMA cohort study

To investigate the time-dependent effects of traditional risk factors on functional disability in all-cause mortality post-stroke, we evaluated data from a long-term stroke cohort. Baseline cerebrovascular risk factors (CVRF) and functionality at 1 and 6 months were evaluated in survivors from a prospective stroke cohort using the modified Rankin scale (m-RS), which classifies participants as improvement of disability, unchanged disability (at least moderate), and worsening disability. Cox regression models considering baseline risk factors, medication use, and functionality 6 months after stroke were fitted to identify their time-dependent effects up to 12 years of follow-up. Adjusted hazard ratios (HR) with 95% confidence intervals (CI) are presented. Among 632 survivors (median age 68, 54% male, 71% first-ever episode), age and functional disability (unchanged and worsening) 6 months after ischemic stroke had time-dependent effects on all-cause mortality risk up to 12 years of follow-up. The most impacting risk factors were unchanged (at least moderate) (HR, 2.99; 95%CI: 1.98-4.52) and worsening disability (HR, 2.85; 95%CI: 1.26-6.44), particularly in the first two years after a stroke event (Time 1: ≥6 mo to <2.5 y). Worsening disability also impacted mortality in the period from ≥2.5 to <7.5 years (Time 2) of follow-up (HR, 2.43 (95%CI: 1.03-5.73). Other baseline factors had a fixed high-risk effect on mortality during follow-up. Post-stroke and continuous medication use had a fixed protective effect on mortality. Functional disability was the main contributor with differential risks of mortality up to 12 years of follow-up.

Cardio-cerebrovascular complications in COVID-19 patients: A retrospective cohort study

Background

Recent studies have highlighted the cardio-cerebrovascular manifestations of coronavirus disease 2019 (COVID-19).

Objective

This study aimed to analyze the likelihood of cardiovascular and cerebrovascular manifestations among patients with COVID-19-positive individuals in South Korea.

Methods

A cohort database for COVID-19 from the National Health Insurance Service was used which included patients diagnosed with COVID-19 between January 1 and June 4, 2020. Individuals who tested COVID-19 positive, notwithstanding the severity of the disease, were designated as cases. COVID-19- negative individuals were used as controls for the study. The exclusion criteria included people who had a history of cardiovascular and cerebrovascular diseases between 2015 and 2019. A new diagnosis of cardiovascular and cerebrovascular complications was considered the primary endpoint. The adjusted incidence rate ratio (IRR) of development of complications was estimated using log-link Poisson regression. The model was adjusted at two levels, the first one included age and sex while the second included age, sex, residence area, and level of income. The hazard ratio (HR) was estimated using Cox-proportional hazard regression analysis while adjusting for all demographic variables and covariates.

Results

Significant results were obtained for acute conditions, such as ischemic heart disease and cerebral hemorrhage. The IRR of COVID-19- positive individuals compared with that of controls for the diagnosis of ischemic heart disease was 1.78 (1.57-2.02; 95% confidence interval [CI]) when adjusted for age and sex. HR was calculated as 3.02 (2.19-4.17; 95% CI) after adjusting for the covariates. In case of cerebral hemorrhage, the adjusted IRR was 2.06 (1.25-3.40; 95% CI) and the adjusted HR was 4.08 (0.90-19.19; 95% CI).

Conclusion

The findings of our study suggest that COVID-19 infection can be a significant risk factor for acute cardiovascular complications, such as ischemic heart disease and acute cerebrovascular complications, such as cerebral infarction, after properly adjusting for covariates.

Age differences in the association of physical leisure activities with incident disability among community-dwelling older adults

Background

The relationship between leisure activities (LA) in old age and prevention of disability has not been fully investigated, and age and gender differences of these relationships are unknown. This study aimed to investigate whether physical and cognitive LA predicted incident disability among community-dwelling older adults by age and gender.

Methods

We prospectively observed 8,275 residents aged 65 or above without disability at baseline for 3 years. Incident disability was defined as a new certification of the public long-term care insurance system. LA were classified into two types: physical LA and cognitive LA. The frequency of LA was categorized into frequent (i.e., once a week or more), moderate (i.e., monthly or yearly), and non-engagement. Covariates included age, gender, family number, education, perceived economic situation, body mass index, chronic medical conditions, alcohol consumption, smoking status, regular dental visits, depression, cognitive functioning, and social participation. Multivariable Poisson regression models were used to estimate adjusted cumulative incidence ratio (CIR) and 95% confidence interval (CI) for incident disability. We performed stratified analyses by age groups (i.e., the young-old aged 65–74 and the old-old aged 75–97) and gender (i.e., men and women).

Results

The 3-year cumulative incidence of disability was 7.5%. After adjustment for covariates and mutual adjustment for both types of LA, a significant dose-response relationship between more frequent LA and lower risk of incident disability was found in young-old physical LA (P-trend < 0.001), in old-old cognitive LA (P-trend = 0.012), in male cognitive LA (P-trend = 0.006), and in female physical LA (P-trend = 0.030). Compared with people without LA, adjusted CIR (95% CI) of frequent LA was 0.47 (0.30–0.74) in young-old physical, 0.75 (0.58–0.96) in old-old cognitive, 0.65 (0.46–0.89) in male cognitive, and 0.70 (0.52–0.95) in female physical. Regarding the effect modification according to age and gender, only interaction between age and physical LA significantly prevented incident disability (P for interaction = 0.019).

Conclusion

We found age differences in the association of physical LA with incident disability among community-dwelling older adults. An effective measure to prevent long-term care in the community would be to recommend frequent physical LA for the young-old.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.21-00018.

Homocysteine, hypertension, and risks of cardiovascular events and all-cause death in the Chinese elderly population: a prospective study

BACKGROUND

Increased homocysteine levels are associated with the risk of cardiovascular disease (CVD) and death. However, their prevention has not been effective in decreasing CVD risk. This study investigated the individual and combined associations of hyperhomocysteinemia and hypertension with incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.

METHODS

This prospective study was conducted among 1,257 elderly participants (mean age: 69 years). A questionnaire survey, physical examinations, and laboratory tests were conducted to collect baseline data. Hyperhomocysteinemia was defined as homocysteine level ≥ 15 µmol/L. H-type hypertension was defined as concomitant hypertension and hyperhomocysteinemia. Multivariate Cox regression analysis was used to evaluate individual and combined associations of hyperhomocysteinemia and hypertension with the risks of incident CVD events and all-cause death.

RESULTS

Over a median of 4.84-year follow-up, hyperhomocysteinemia was independently associated with incident CVD events and all-cause death. The hazard ratios (HRs) were 1.45 (95% CI: 1.01−2.08) for incident CVD events and 1.55 (95% CI: 1.04−2.30) for all-cause death. After adjustment for confounding factors, H-type hypertension had the highest HRs for incident CVD events and all-cause death. The fully adjusted HRs were 2.44 for incident CVD events (95% CI: 1.28−4.65), 2.07 for stroke events (95% CI: 1.01−4.29), 8.33 for coronary events (95% CI: 1.10−63.11), and 2.31 for all-cause death (95% CI: 1.15−4.62).

CONCLUSIONS

Hyperhomocysteinemia was an independent risk factor, and when accompanied by hypertension, it contributed to incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.

Homocysteine and the Risk of Cardiovascular Events and All-Cause Death in Elderly Population: A Community-Based Prospective Cohort Study

Background

The association between homocysteine and cardiovascular diseases (CVD) and all-cause death was inconclusive. A community-based prospective cohort study was carried out in Beijing to evaluate this association in elderly population for more effective clinical prediction and primary prevention of CVD.

Patients and Methods

Participants were randomly selected from Beijing, China. Questionnaire survey, physical examinations, and laboratory tests were carried out to collect baseline information and investigate clinical characteristics. Each participant was predetermined to be followed by 5 years. CVD events and death were collected as primary variables. A Cox regression analysis was performed to assess the risk of CVD events, CVD death, and all-cause death contributed by homocysteine as well as some other risk factors.

Results

A total of 1257 participants with an average age of 69.16 years were enrolled in this study. After adjusting for confounders, the hazard ratios (HRs) and 95% confidence intervals of CVD event, CVD death, and all-cause death caused by intermediate-to-severe hyperhomocysteinemia as compared with normal homocysteine levels were 1.68 (95% CI 1.06–2.67), 1.97 (95% CI 0.95–4.29) and 2.02 (95% CI 1.26–3.24), respectively. Intermediate-to-severe hyperhomocysteinemia increased the risks of CVD event (HR 2.07, 95% CI 1.01–4.26) and all-cause death (HR 3.08, 95% CI 1.56–6.07) among male participants. However, the positive association was not statistically significant among female participants (HR 1.59, 95% CI 0.83–3.04 for CVD event and HR 0.90, 95% CI 0.52–6.07 for all-cause death). Every 5μmol/L increment in homocysteine concentration was shown to be associated with a 4% (HR 1.04, 95% CI 1.01–1.07) and 5% (HR 1.05, 95% CI 1.01–1.07) higher risk of CVD events and all-cause death in all participants. There was no significant association between moderate hyperhomocysteinemia and the risk of the CVD events and all-cause death.

Conclusion

Intermediate-to-severe hyperhomocysteinemia was significantly associated with CVD events and all-cause death in elderly population without a history of ischemia or congestive heart failure (CHF). The positive association was pronounced among males.

High prevalence of obesity-related hypertension among adults aged 40 to 79 years in Southwest China

This study aimed to assess the prevalence and related factors of obesity-related hypertension among adults aged 40 to 79 years in Southwest China. From September 2013 to March 2014, a multi-stage, stratified sampling method was conducted on 10,589 people aged 40 to 79 years and living in Chengdu and Chongqing investigated by using a questionnaire and performing physical and biochemical measurements. The prevalence of obesity-related hypertension and hypertension overall (systolic ≥130 mmHg and/or diastolic ≥80 mmHg or treated hypertension) was 22.8% and 57.4%, respectively, among all participants. For obesity-related hypertension, the prevalence was higher in women than in men (24.7% versus 19.4%, p < 0.001). For people in the age ranges of 40-49, 50-59, 60-69, and ≥70, the prevalence of obesity-related hypertension were 11.8%, 22.6%, 30.7%, and 36.6%, respectively. Participants with obesity-related hypertension as opposed to those with non-obesity-related hypertension had a higher prevalence of hypertriglyceridemia, high low-density lipoprotein cholesterolemia, diabetes, and hyperuricemia (all p < 0.05). Multivariate logistic regression analysis showed that age, female gender, current smoking, hypertriglyceridemia, diabetes and family history of hypertension were all positively correlated with obesity-related hypertension, whereas higher education level and having spouse were negatively correlated with obesity-related hypertension. The prevalence of obesity-related hypertension was high among adults aged 40 to 79 years in Southwest China. Cardiometabolic abnormalities among participants with obesity-related hypertension were more serious and frequently present than in those with non-obesity-related hypertension. Aggressive and holistic strategies aiming at the prevention and treatment of obesity-related hypertension are needed.

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis

OBJECTIVE

To systematically review the literature relating to the impact of multiple co-occurring modifiable risk factors for cognitive decline and dementia.

DESIGN

A systematic review and meta-analysis of the literature relating to the impact of co-occurring key risk factors for incident cognitive decline and dementia. All abstracts and full text were screened independently by two reviewers and each article assessed for bias using a standard checklist. A fixed effects meta-analysis was undertaken.

DATA SOURCES

Databases Medline, Embase and PsycINFO were searched from 1999 to 2017.

ELIGIBILITY CRITERIA

For inclusion articles were required to report longitudinal data from participants free of cognitive decline at baseline, with formal assessment of cognitive function or dementia during follow-up, and an aim to examine the impact of additive or clustered comorbid risk factor burden in with two or more core modifiable risk factors.

RESULTS

Seventy-nine full-text articles were examined. Twenty-two articles (18 studies) were included reporting data on >40 000 participants. Included studies consistently reported an increased risk associated with greater numbers of intraindividual risk factors or unhealthy behaviours and the opposite for healthy or protective behaviours. A meta-analysis of studies with dementia outcomes resulted in a pooled relative risk for dementia of 1.20 (95% CI 1.04 to 1.39) for one risk factor, 1.65 (95% CI 1.40 to 1.94) for two and 2.21 (95% CI 1.78 to 2.73) for three or more, relative to no risk factors. Limitations include dependence on published results and variations in study outcome, cognitive assessment, length of follow-up and definition of risk factor exposure.

CONCLUSIONS

The strength of the reported associations, the consistency across studies and the suggestion of a dose response supports a need to keep modifiable risk factor exposure to a minimum and to avoid exposure to additional modifiable risks. Further research is needed to establish whether particular combinations of risk factors confer greater risk than others.

PROSPERO REGISTRATION NUMBER

42016052914.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

The risk factors of 9-year follow-up on hypertension in middle-aged people in Tujia-Nationality settlement of China

The aim of this study was to investigate the risk factors of hypertension in middle-aged people within the Tujia-Nationality settlement in China. Demographics questionnaires and fitness tests were performed to identify the risk factors of hypertension in middle-aged people in the years 2005, 2010 and 2014 in the area of southwest Hubei of China. Of the 2428 participants, 568 were classified as hypertensive, giving an overall occurrence of hypertension at 23.4%, and the prevalence of hypertension was the highest in the year 2014 (34.9%). Furthermore, Tujia minority had a significantly higher risk for having hypertension (odds ratio=1.055 with 95% confidence interval (CI): 1.039-1.072; P=0.001) than Han people. Individuals with the lowest level of cardiorespiratory fitness (CRF) had a 2.483-fold risk for hypertension (95% CI, 1.530-4.031; P=0.001). Obesity and overweight individuals increased the risk by 3.470-fold and 2.124-fold, respectively, for having hypertension compared to normal weight people. Finally, white-collar workers had a 58.1 and 31.8% higher risk for hypertension than blue-collar workers in rural and urban areas, respectively. These results demonstrated that the prevalence of hypertension was higher between 2011 and 2014 in the area. The main risk factors for developing hypertension were found to be sex (as woman), Tujia minority, white-collar workers, overweight-obese, those with a middle school education, and those with the lowest CRF.

A competing-risk-based score for predicting twenty-year risk of incident diabetes: the Beijing Longitudinal Study of Ageing study

Few risk tools have been proposed to quantify the long-term risk of diabetes among middle-aged and elderly individuals in China. The present study aimed to develop a risk tool to estimate the 20-year risk of developing diabetes while incorporating competing risks. A three-stage stratification random-clustering sampling procedure was conducted to ensure the representativeness of the Beijing elderly. We prospectively followed 1857 community residents aged 55 years and above who were free of diabetes at baseline examination. Sub-distribution hazards models were used to adjust for the competing risks of non-diabetes death. The cumulative incidence function of twenty-year diabetes event rates was 11.60% after adjusting for the competing risks of non-diabetes death. Age, body mass index, fasting plasma glucose, health status, and physical activity were selected to form the score. The area under the ROC curve (AUC) was 0.76 (95% Confidence Interval: 0.72-0.80), and the optimism-corrected AUC was 0.78 (95% Confidence Interval: 0.69-0.87) after internal validation by bootstrapping. The calibration plot showed that the actual diabetes risk was similar to the predicted risk. The cut-off value of the risk score was 19 points, marking mark the difference between low-risk and high-risk patients, which exhibited a sensitivity of 0.74 and specificity of 0.65.

Prediction of the 20-year incidence of diabetes in older Chinese: Application of the competing risk method in a longitudinal study

The competing risk method has become more acceptable for time-to-event data analysis because of its advantage over the standard Cox model in accounting for competing events in the risk set. This study aimed to construct a prediction model for diabetes using a subdistribution hazards model.We prospectively followed 1857 community residents who were aged ≥ 55 years, free of diabetes at baseline examination from August 1992 to December 2012. Diabetes was defined as a self-reported history of diabetes diagnosis, taking antidiabetic medicine, or having fasting plasma glucose (FPG) ≥ 7.0 mmol/L. A questionnaire was used to measure diabetes risk factors, including dietary habits, lifestyle, psychological factors, cognitive function, and physical condition. Gray test and a subdistribution hazards model were used to construct a prediction algorithm for 20-year risk of diabetes. Receiver operating characteristic (ROC) curves, bootstrap cross-validated Wolber concordance index (C-index) statistics, and calibration plots were used to assess model performance.During the 20-year follow-up period, 144 cases were documented for diabetes incidence with a median follow-up of 10.9 years (interquartile range: 8.0-15.3 years). The cumulative incidence function of 20-year diabetes incidence was 11.60% after adjusting for the competing risk of nondiabetes death. Gray test showed that body mass index, FPG, self-rated heath status, and physical activity were associated with the cumulative incidence function of diabetes after adjusting for age. Finally, 5 standard risk factors (poor self-rated health status [subdistribution hazard ratio (SHR) = 1.73, P = 0.005], less physical activity [SHR = 1.39, P = 0.047], 55-65 years old [SHR = 4.37, P < 0.001], overweight [SHR = 2.15, P < 0.001] or obesity [SHR = 1.96, P = 0.003], and impaired fasting glucose [IFG] [SHR = 1.99, P < 0.001]) were significantly associated with incident diabetes. Model performance was moderate to excellent, as indicated by its bootstrap cross-validated discrimination C-index (0.74, 95% CI: 0.70-0.79) and calibration plot.Poor self-rated health, physical inactivity, being 55 to 65 years of age, overweight/obesity, and IFG were significant predictors of incident diabetes. Early prevention with a goal of achieving optimal levels of all risk factors should become a key element of diabetes prevention.

A Novel Risk Score to the Prediction of 10-year Risk for Coronary Artery Disease Among the Elderly in Beijing Based on Competing Risk Model

The study aimed to construct a risk prediction model for coronary artery disease (CAD) based on competing risk model among the elderly in Beijing and develop a user-friendly CAD risk score tool. We used competing risk model to evaluate the risk of developing a first CAD event. On the basis of the risk factors that were included in the competing risk model, we constructed the CAD risk prediction model with Cox proportional hazard model. Time-dependent receiver operating characteristic (ROC) curve and time-dependent area under the ROC curve (AUC) were used to evaluate the discrimination ability of the both methods. Calibration plots were applied to assess the calibration ability and adjusted for the competing risk of non-CAD death. Net reclassification index (NRI) and integrated discrimination improvement (IDI) were applied to quantify the improvement contributed by the new risk factors. Internal validation of predictive accuracy was performed using 1000 times of bootstrap re-sampling. Of the 1775 participants without CAD at baseline, 473 incident cases of CAD were documented for a 20-year follow-up. Time-dependent AUCs for men and women at t = 10 years were 0.841 [95% confidence interval (95% CI): 0.806-0.877], 0.804 (95% CI: 0.768-0.839) in Fine and Gray model, 0.784 (95% CI: 0.738-0.830), 0.733 (95% CI: 0.692-0.775) in Cox proportional hazard model. The competing risk model was significantly superior to Cox proportional hazard model on discrimination and calibration. The cut-off values of the risk score that marked the difference between low-risk and high-risk patients were 34 points for men and 30 points for women, which have good sensitivity and specificity. A sex-specific multivariable risk factor algorithm-based competing risk model has been developed on the basis of an elderly Chinese cohort, which could be applied to predict an individual's risk and provide a useful guide to identify the groups at a high risk for CAD among the Chinese adults over 55 years old.

Time series analysis of the association between ambient temperature and cerebrovascular morbidity in the elderly in Shanghai, China

Research on the association between ambient temperature and cerebrovascular morbidity is scarce in China. In this study, we applied mixed generalized additive model (MGAM) to daily counts of cerebrovascular disease of Shanghai residents aged 65 years or older from 2007-2011, stratified by gender. Weighted daily mean temperature up to lags of one week was smoothed by natural cubic spline, and was added into the model to assess both linear and nonlinear effects of temperature. We found that when the mean temperature increased by 1 °C, the male cases of cerebrovascular disease reduced by 0.95% (95% Confidence Interval (CI): 0.80%, 1.10%) or reduced by 0.34% (95% CI: -0.68, 1.36%) in conditions of temperature was below or above 27 °C. However, for every 1 °C increase in temperature, the female cases of cerebrovascular disease increased by 0.34% (95% CI: -0.26%, 0.94%) or decreased by 0.92% (95% CI: 0.72, 1.11%) in conditions of temperature was below or above 8 °C, respectively. Temperature and cerebrovascular morbidity is negatively associated in Shanghai. MGAM is recommended in assessing the association between environmental hazards and health outcomes in time series studies.

VKORC1 and CD-14 genetic polymorphisms associate with susceptibility to cardiovascular and cerebrovascular diseases

OBJECTIVE

To investigate the associations of VKORC1 rs2359612 and rs9923231 and CD-14 rs2569190 with susceptibility to cardiovascular and cerebrovascular diseases (CCVD).

METHODS

A case-control study was conducted with 614 cases of CCVD patients selected at our hospital between January 2011 and June 2012 as case group and 590 healthy individuals participating physical examination during the same period as control group. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to detect genotypes of VKORC1 and CD-14 genetic polymorphisms. SHEsis software was used to conduct haplotype analysis and logistic regression analysis was used to identify risk factors for CCVD.

RESULTS

The genotype and allele frequencies of VKORC1 rs2359612 and rs9923231 and CD-14 rs2569190 between the case and control groups were statistically different (all P<0.05). Haplotype analysis showed that the frequencies of CAT and TAT haplotypes were significantly higher while the frequencies of TAC and TGC haplotypes were significantly lower in the case group than those in the control group (P = 0.013, 0.029, 0.019 and 0.042, respectively). Logistic regression analysis showed that age, systolic pressure, smoking history and VKORC1 rs2359612 maybe risk factors for CCVD; and body mass index (BMI), diastolic pressure and VKORC1 rs9923231 may be protective factors for CCVD (all P<0.05).

CONCLUSION

VKORC1 rs2359612 and rs9923231, and CD-14 rs2569190 might associate with susceptibility to CCVD. CAT and TAT haplotypes may be risk factors while TAC and TGC haplotype may be protective factors for CCVD.

Is occupation a good predictor of self-rated health in China?

Background

China’s rapidly changing economic landscape has led to widening social inequalities. Occupational status in terms of occupational type and prestige may reflect these socio-structural shifts of social position and be more predictive of self-rated health status than income and education, which may only reflect more gradual acquisitions of social status over time. The goals of this study were to understand the role of occupational status in predicting self-rated health, which is well known to be associated with long-term mortality, as well as compare the occupational status to the other major socioeconomic indicators of income and education.

Methods

Data from the 2010 baseline surveys of the China Family Panel Studies, which utilized multi-stage probability sampling with implicit stratification was used. Logistic regression was used to examine the relationship of various socioeconomic indicators (i.e. occupational status, income, and education) with self-rated health as the primary outcome of interest. A series of models considered the associations of occupational category or occupational prestige with self-rated health.

Results

The final sample consisted of 14,367 employed adults aged 18–60, which was nationally representative of working adults in China. We found that occupation was not a major predictor of self-rated health in China when age, ethnicity, location, marital status, physical and mental health status were controlled for, with the exception of women working in lower grade management and professional jobs (OR = 1.82, 95% CI: 1.03–3.22). In comparison, income followed by education exhibited greater association with self-rated health. The highest income group had the least probability to report poor health (In men: OR = 0.30, 95% CI: 0.21–0.43. In women: OR = 0.44, 95% CI: 0.26–0.73). People educated with junior high school had better self-rated health than those with primary and below education level (In men: OR = 0.62, 95% CI: 0.50–0.75. In women: OR = 0.53, 95% CI: 0.42–0.68). Income, education and occupation were correlated with each other.

Conclusions

Within the context of rapid societal changes in China, income and its implications for greater healthcare access and benefits had the greatest association with self-rated health followed by education. Occupational status was not associated. Occupational categories and prestige should be better adapted to reflect China’s unique sociopolitical and historical context.

Small-animal PET demonstrates brain metabolic change after using bevacizumab in a rat model of cerebral ischemic injury

To evaluate the effect of bevacizumab on cerebral ischemia, we used 2-deoxy-2-(18)F-fluoro-D-glucose ((18)F-FDG) small-animal positron emission tomography (PET) in the middle cerebral artery occlusion (MCAO) rat model. After baseline neurologic function tests and PET studies, MCAO Sprague-Dawley rats received bevacizumab or normal saline (controls). Weekly PET imaging and neurologic function tests showed that the (18)F-FDG accumulation in the bevacizumab group was similar to that in the controls during the first 2 weeks, but lower than in controls at weeks 3 and 4. However, no difference was found in neurological scores between the groups. The number of von Willebrand factor-positive cells in the bevacizumab group was lower than that in controls. The expression of vascular endothelial growth factor was higher than in controls at week 4. These results suggested that bevacizumab does not influence functional recovery in this model of cerebral ischemia during a 4-week period, but inhibits vascular formation and metabolic recovery, which may be considered in cancer patients with a recent ischemic stroke.

Aging, the metabolic syndrome, and ischemic stroke: redefining the approach for studying the blood-brain barrier in a complex neurological disease

The blood-brain barrier (BBB) has many important functions in maintaining the brain's immune-privileged status. Endothelial cells, astrocytes, and pericytes have important roles in preserving vasculature integrity. As we age, cell senescence can contribute to BBB compromise. The compromised BBB allows an influx of inflammatory cytokines to enter the brain. These cytokines lead to neuronal and glial damage. Ultimately, the functional changes within the brain can cause age-related disease. One of the most prominent age-related diseases is ischemic stroke. Stroke is the largest cause of disability and is third largest cause of mortality in the United States. The biggest risk factors for stroke, besides age, are results of the metabolic syndrome. The metabolic syndrome, if unchecked, quickly advances to outcomes that include diabetes, hypertension, cardiovascular disease, and obesity. The contribution from these comorbidities to BBB compromise is great. Some of the common molecular pathways activated include: endoplasmic reticulum stress, reactive oxygen species formation, and glutamate excitotoxicity. In this chapter, we examine how age-related changes to cells within the central nervous system interact with comorbidities. We then look at how comorbidities lead to increased risk for stroke through BBB disruption. Finally, we discuss key molecular pathways of interest with a focus on therapeutic targets that warrant further investigation.