[Correlation between fetal borderline ventriculomegaly and chromosomal abnormalities]

Objective: To assess the association between fetal borderline ventriculomegaly (VM) diagnosed by prenatal ultrasound and chromosomal abnormality. Methods: Sonographic manifestation and chromosome of 129 cases with borderline VM diagnosed by prenatal sonography were analyzed retrospectively. All subjects were divided into 3 groups, 80 cases (62.0%, 80/129) in isolated VM (IVM) group, 27 cases (20.9%, 27/129) of VM with no additional structural abnormality group (including ultrasonic soft marker, abnormal volume of amniotic fluid and fetal growth restriction) and 22 cases (17.1%, 22/129) of VM with structural abnormality. Furthermore, the IVM group was sub-grouped according to fetal sex, lesion position and degree of expansion. The results of chromosome detection in different sub-group were analyzed statistically. Results: (1) Overall situation: in 129 enrolled cases of borderline VM, 8 cases of chromosomal abnormality were detected by CMA and the positive detection rate was 6.2% (8/129) , of which 2 cases were abnormal karyotype and 6 cases were pathologic copy number variation (p-CNV) . (2) The results of fetal chromosomal abnormalities detected in 3 groups: there were no case of abnormal karyotype and 4 cases of p-CNV in IVM group, the detection rate of chromosome abnormalities was 5.0% (4/80) . One case of abnormal karyotype and 2 cases of p-CNV in VM with no additional structural abnormality group, the detection rate was 11.1% (3/27) . One case of abnormal karyotype and no case of p-CNV in VM with structural abnormality group, the detection rate was 4.5% (1/22) . There were no significant difference among 3 groups (all P>0.05) . Conclusions: The risk of chromosomal abnormaliy increases in fetus with borderline VM. When the fetal VM is found by ultrasound, it is necessary to perform comprehensive scanning and regular follow-up. Fetal chromosomes examination is recommended.

[Analysis of copy number variation by CMA in fetus with increased nuchal translucency]

Objective: To investigated the clinical value of chromosomal microarray analysis (CMA) in fetuses with increased nuchal translucency (NT) . Methods: Totally 101 cases out of 19 261 singleton fetuses who underwent the first trimester (11-13⁺⁶ weeks) ultrasound examination from January 2015 to June 2017 at First Affiliated Hospital of Sun Yat-sen University were diagnosed with NT ≥2.5 mm and underwent invasive prenatal test for fetal karyotype and CMA. According to the combination of other ultrasound abnormalities, the cases were divided into isolated group (67.3%, 68/101) and complicated group (32.7%, 33/101) . In addition, the cases were divided into 5 groups according to the thickness of NT, 2.5-2.9 mm (borderline thickening; 16.8%, 17/101) , 3.0-3.4 mm (33.7%, 34/101) , 3.5-4.4 mm (16.8%, 17/101) , 4.5-5.4 mm (15.8%, 16/101) , and ≥5.5 mm (16.8%, 17/101) . Chi square test was used to detect the different rates of other combined ultrasound abnormalities and abnormal chromosome between 5 groups. Results: The median thickness of NT was 3.4 mm (2.5-8.5 mm) . And 32 cases (31.7%, 32/101) had abnormal karyotype. There was a significant difference in the frequency of abnormal karyotype between the isolated and the complicated group (20.6% vs 54.5%, P<0.01) . Among 69 cases (68.3%, 69/101) of normal karyotype, 3 cases (4.3%, 3/69) were detected with pathogenic copy number variation (CNV) by CMA. Thirty-five cases with chromosomal abnormalities (include abnormal karyotype and pathogenic CNV) , there was a significant difference in the frequency of chromosomal abnormalities between the isolated and the complicated group (23.5% vs 57.6%, P=0.001) . The median age of pregnant women in 5 groups was 35 years (24-39 years) , 33 years (23-46 years) , 31 years (21-46 years) , 33 years (21-41 years) and 35 years (21-43 years) . The rates of chromosomal abnormalities increased with the increase of NT thickness. There was significant difference in the incidence of associated chromosomal abnormalities among 5 groups (P<0.05) . Comparative analysis within the 5 groups, the incidence of associated chromosomal abnormalities between NT 2.5-2.9 mm and ≥5.5 mm was significantly different (P=0.005) , while the differences between the other groups were not significant (P>0.05) . Conclusions: There is a high risk of fetal chromosomal abnormalities in borderline NT thickening (2.5-2.9 mm) at advanced maternal age, but the pathogenic CNV is not detected. Chromosomal microdeletion or microduplication could be further detected in the NT thickening (≥3.0 mm) fetuses with normal karyotype by chromosome microarray analysis, while the positive rate is relatively low, and the variants of unknown significance might be detected.

Increased CD4+CD25-Foxp3+ T cells in Chinese systemic lupus erythematosus: correlate with disease activity and organ involvement

Objective

The increment of CD4+CD25−Foxp3+T cells has been reported in systemic lupus erythematosus (SLE) patients. However, the exact identity of this T cell subset is still unclear. Thus, we analyzed CD4+CD25−Foxp3+T cells and Treg cells (CD4+CD25+Foxp3+ T cells) in a large sample of Chinese SLE patients in different disease states.

Methods

A total of 280 SLE patients and 38 healthy volunteers were enrolled, which included 21 patients with untreated new-onset lupus (UNOL), 13 patients with drug withdrawal more than 6 months and 246 patients with treatments. Phenotypic and functional analysis of peripheral blood CD4+CD25−Foxp3+ T cells and Treg cells were performed by flow cytometry. The correlation of CD4+CD25−Foxp3+T cells and Treg cells with disease activity, clinical indicators and organ involvement were analyzed.

Results

CD4+CD25−Foxp3+ T cells and Treg cells were significantly increased in SLE patients and showed significantly positive correlations with disease activity. CD4+CD25−Foxp3+ T cells were significantly increased in patients with skin and hematologic involvement as well as arthritis. Diverse changes between CD4+CD25−Foxp3+ T cells and Treg cells when faced with different medications, especially HCQ and MMF. CD4+CD25−Foxp3+ T cells expressed more IFN-γ and less CTLA-4 than CD4+CD25+Foxp3+ T cells, which were similar to CD4+CD25+Foxp3− T cells, and expressed similar IL-17, ICOS and Helios to CD4+CD25+Foxp3+ T cells. The synthesis capacity of IL-10 of CD4+CD25−Foxp3+ T cells and the expression of GITR on CD4+CD25−Foxp3+ T cells were between CD4+CD25+Foxp3+ and CD4+CD25+Foxp3− T cells.

Conclusions

Our results indicate that increased CD4+CD25−Foxp3+ T cells in lupus patients, which combined the features of suppression and pro-inflammatory, may serve as a biomarker for disease activity and organ involvement in SLE.

Cohort Profile: The Chongqing Cancer Cohort Study (CCCS) of the Urban Population in Southwest China

Purpose: Urbanization is causing an increasingly negative effect on public health in China. This study was established to examine the associations between socio-economic and environmental exposures and the potential impact of gene-environment interactions and cancer risk of urban population in Chongqing, China. Participants: The cohort was established in Beibei District of Chongqing in southwest China. Between March 2016 and December 2016, we enrolled 57,332 adults who were 40-69 years of age, and collected baseline data on demographic information, socio-economic status, lifestyle, family and personal disease histories through face-to-face interviews using a standardized questionnaire. Regular follow-up including face-to-face interviews will take place every 5 years. Findings to date: Ninety-nine percent (56658/57332) of the participants completed the baseline assessment. The eligible participants had a mean age of 54.8 years, and 51.42% were females. Nearly three-fifths of participants having a normal BMI (18.5 to 23.9 kg/m2) and one-third being overweight (24.0 to 27.9 kg/m2). Among males, 29.58% were smokers and 21.08% were alcohol users. Among females, 1.49% were smokers and 1.66% were alcohol users. Among all participants, 7.03% of males and 9.08% of females reported their family history of cancer. Future plans: The relationships of modifiable risk factors with the cancer risk will be analyzed. Meanwhile, participants will be closely tracked to minimize loss to follow-up. We plan to construct a risk prediction model on cancer and verify the prediction model by genome-wide association studies (GWAS). The successful completion of this cohort study will allow for better targeting of cancer screening to those at highest risk in urban population of China and provide clinicians and policymakers with a practical predication rule.

Spectral Evidence for Emergent Order in Ba_{1-x}Na_{x}Fe_{2}As_{2}

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

Impact of UVA pre-radiation on UVC disinfection performance: Inactivation, repair and mechanism study

Ultraviolet (UV) light emission diode (LED), which is mercury free and theoretically more energy efficient, has now become an alternative to conventional UV lamps in water disinfection industry. In this research, the disinfection performance of a novel sequential process, UVA_365nm LED followed by UVC_265nm LED (UVA-UVC), was evaluated. The results revealed that the responses of different bacterial strains to UVA-UVC varied. Coupled with appropriate dosages of UVC, a 20 min UVA pre-radiation provided higher inactivations (log inactivation) of E. coli ATCC 11229, 15597 and 700891 by 1.2, 1.4 and 1.2 times, respectively than the sum of inactivations by UVA alone and UVC alone. On the contrary, the inactivation of E. coli ATCC 25922, the most UVC sensitive strain, decreased from 3 log to 1.8 log after UVA pre-radiation. A 30 min UVA pre-radiation did not affect the photo repair capacity of the four strains (n = 23, p > 0.1), but their dark repair ability was significantly inhibited (n = 14, p < 0.05). Mechanism study was conducted for two representative strains, E. coli ATCC 15597 and 25922 to understand the observed effect. The hypothesis that UVA pre-radiation promoted the yield of reactive oxygen species (ROS) was rejected. ELISA results indicated that 18% more cyclobutane pyrimidine dimers (CPD) were formed in E. coli ATCC 15597 with UVA pre-radiation (n = 3, p < 0.01), however, the CPD levels of E. coli ATCC 25922 was the same with or without UVA pre-radiation (n = 3, p > 0.01). Considering the results of both dark repair and CPD formation, it was concluded that the increased UV sensitivity of E. coli 15597 was originated from the increased CPD. For E. coli ATCC 25922, the enhanced UV resistance was attributed to the strain's adoption of a survival strategy, translesion DNA synthesis (TLS), when triggered by UVA pre-radiation. The study on UmuD protein, which is a key protein during TLS, confirmed this hypothesis.

Hemoglobin A1c predicts hemorrhagic transformation and poor outcomes after acute anterior stroke

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a major complication of acute ischaemic stroke that is potentially related to clinical deterioration. The objective of this study was to assess whether chronic hyperglycemia is a predictive factor of HT in patients with acute anterior stroke.

METHODS

Patients with acute anterior stroke were included in this study. Hemoglobin A1c (HbA1c) was measured in the morning after hospitalization. HT was detected by computed tomography scans or gradient echo magnetic resonance imaging performed 4 (±2) days after onset. Univariate and multivariate logistic regression analyses were used to assess the risks for HT and short-term outcomes.

RESULTS

Of the 426 patients included, 93 (21.8%) had HT: 61 (14.3%) presented with hemorrhagic infarction and 32 (7.5%) presented with parenchymal hematoma. A total of 54 patients received thrombolytic treatment and 18 (33.3%) were found to have HT. In the multivariate analysis, HbA1c [odds ratio (OR), 1.294; 95% confidence interval (CI), 1.097-1.528], infarction size (OR, 3.358; 95% CI, 1.748-6.449) and thrombolytic therapy (OR, 3.469; 95% CI, 1.757-6.847) were predictors of HT. The predictive effect of HbA1c on HT was still observed in both groups when patients were stratified according to the levels of fasting blood glucose. HbA1c was found to be a predictor of poor outcomes in the multilogistic regression analysis (OR, 1.482; 95% CI, 1.228-1.788).

CONCLUSIONS

Higher HbA1c was independently related to HT and poor neurological outcomes in patients with ischaemic stroke. These findings have significant implications for the treatment of diabetes and glucose management in patients with diabetes mellitus and/or acute ischaemic stroke.

Multiscale prediction of acoustic properties for glass wools: Computational study and experimental validation

This work is concerned with the multiscale prediction of the transport and sound absorption properties associated with industrial glass wool samples. In the first step, an experimental characterization is performed on various products using optical granulometry and porosity measurements. A morphological analysis, based on scanning electron imaging, is further conducted to identify the probability density functions associated with the fiber angular orientation. The key morphological characterization parameters of the microstructure, which serve as input parameters of the model, include the porosity, the weighted volume diameter accounting for both lengths and diameters of the analyzed fibers (and therefore the specific surface area of the random fibrous material), and the preferred out-of-plane fiber orientation generated by the manufacturing process. A computational framework is subsequently proposed and allows for the reconstruction of an equivalent fibrous network. A fully stochastic microstructural model, parameterized by the probability laws inferred from the database, is also proposed herein. Multiscale simulations are carried out to estimate transport properties and sound absorption. With no adjustable parameter, the results accounting for ten different samples obtained with various processing parameters are finally compared with the experimental data and used to assess the relevance of the reconstruction procedures and the multiscale computations.

A pilot serosurvey of Babesia microti in Chinese blood donors

BACKGROUND AND OBJECTIVES

Babesia spp. are tick-borne, intraerythrocytic protozoan parasites, several of which are transfusion-transmissible. Transfusion-transmitted babesiosis poses serious risk to a diverse patient population, including neonates, patients aged >50 years, the asplenic and the immunocompromised that are over-represented among transfusion recipients. Despite reports of B. microti and B. venatorum in People's Republic of China (PRC), no surveillance of blood donors for Babesia has previously been undertaken. We sought to determine the rates of B. microti seroreactivity in a sample of blood donors in the PRC.

MATERIALS AND METHODS

A pilot serosurvey was conducted of community blood donors (n = 1000) who donated July-August 2016 at Mudanjiang Blood Center (Heilongjiang Province) using indirect fluorescent antibody testing for antibodies against B. microti. The slides were prepared using B. microti-infected hamster blood. Samples that were initially positive to a titre of 64 were subjected to repeat IFA testing. Final seroreactivity was based on repeat reactivity to ≥64.

RESULTS

A total of 1000 individual donor samples were evaluated, comprising 888 whole blood and 112 platelet donations. Thirteen of 1000 (1·3%) donors were seroreactive for B. microti [8 (0·8%) and five (0·05%) at titres of 64 and 128, respectively].

CONCLUSION

Our preliminary findings support the need for expanded Babesia surveillance in Chinese blood donors, replete with molecular evaluation, to evaluate the risk to the blood supply.

Inverse association between plasma homocysteine concentrations and type 2 diabetes mellitus among a middle-aged and elderly Chinese population

BACKGROUND AND AIMS

Plasma homocysteine concentrations have been reported to be associated with type 2 diabetes mellitus (T2DM) with controversial findings. The aim of the present study was to investigate the association between plasma homocysteine concentrations and T2DM.

METHODS AND RESULTS

A cross-sectional study including 19,085 eligible participants derived from the Dongfeng-Tongji cohort was conducted. Plasma homocysteine concentrations were measured by Abbott Architect i2000 Automatic analyzer and T2DM was defined according to American Diabetes Association criteria. Logistic regression model was used to explore the association between plasma homocysteine concentrations and T2DM. The prevalence of T2DM was 19.0% in the whole population (mean age 62.9 years), 21.8% in males, and 17.1% in females. In the multivariable logistic regression analyses, compared with those in the lowest quintile, the OR (95% CI) of T2DM was 1.05 (0.92-1.21), 0.99 (0.86-1.14), 0.90 (0.78-1.05), and 0.77 (0.66-0.90) for quintile 2 to quintile 5 of homocysteine concentrations after adjustment for potential confounders (P for trend < 0.0001). Homocysteine concentrations were associated with decreased T2DM prevalence risk (OR = 0.88 per SD increase of homocysteine concentration; 95% CI: 0.84-0.93). A significant interaction between homocysteine concentrations and drinking status on T2DM prevalence risk was observed (P for interaction = 0.03). The inverse association of plasma homocysteine concentrations with T2DM prevalence risk was observed in non-drinkers but not in current drinkers.

CONCLUSION

Plasma homocysteine concentrations were inversely correlated with T2DM among a middle-aged and elderly Chinese population.

Associations between daily cooking duration and the prevalence of diabetes and prediabetes in a middle-aged and elderly Chinese population: A cross-sectional study

Experimental and epidemiological studies indicated that ambient air pollution was positively associated with diabetes. Few studies investigated the associations between household air pollution, for example, daily cooking duration and diabetes or prediabetes. We conducted a cross-sectional study to investigate the associations of daily cooking duration with the prevalence of diabetes and prediabetes among a middle-aged and elderly population. A total of 26 089 individuals (11 250 males and 14 839 females) derived from the Dongfeng-Tongji cohort study were included. Daily cooking duration was assessed by questionnaire. Diabetes and prediabetes were identified according to the criterion of American Diabetes Association. No significant association was observed between daily cooking duration and the prevalence risk of diabetes (odds ratio[OR] = 0.97, 95% confidence interval[CI]: [0.81-1.16], P for trend = .74); however, longer daily cooking duration was associated with higher prevalence risk of prediabetes (OR = 1.26, 95% CI: 1.07-1.47; P for trend = .003) and hyperglycemia (OR = 1.21, 95% CI: 1.05-1.41; P for trend = .005). Our study suggested that daily cooking duration was not associated with diabetes but with higher prevalence risk of prediabetes/hyperglycemia in a middle-aged and elderly Chinese population.

Use of olmesartan and enteropathy outcomes: a multi-database study

BACKGROUND

Multiple case reports suggest that olmesartan may be linked to sprue-like enteropathy; however, few epidemiological studies have examined this association and results have been mixed.

AIM

To assess whether olmesartan is associated with a higher rate of enteropathy vs other angiotensin II receptor blockers (ARBs).

METHODS

We conducted a cohort study among ARB initiators in 5 US claims databases representing different health insurance programmes. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for enteropathy-related outcomes, including coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy, comparing olmesartan initiators to initiators of other ARBs after propensity score (PS) matching.

RESULTS

We identified 1 928 469 eligible patients. The unadjusted incidence rates were 0.82, 1.41, 1.66 and 29.20 per 1000 person-years for coeliac disease, malabsorption, concomitant diagnoses of diarrhoea and weight loss, and non-infectious enteropathy respectively. HRs after PS matching comparing olmesartan to other ARBs were 1.21 (95% CI, 1.05-1.40), 1.00 (95% CI, 0.88-1.13), 1.22 (95% CI, 1.10-1.36) and 1.04 (95% CI, 1.01-1.07) for each outcome. HRs were larger for patients aged 65 years and older (eg for coeliac disease, 1.57 [95% CI, 1.20-2.05]), for patients receiving treatment for more than 1 year (1.62 [95% CI, 1.24-2.12]), and for patients receiving higher cumulative olmesartan doses (1.78 [95% CI, 1.33-2.37]).

CONCLUSIONS

This large-scale, multi-database study found a higher rate of enteropathy in olmesartan initiators as compared to initiators of other ARBs, although the absolute incidence rate was low in both groups.

Deep sequencing reveals the molecular pathology characteristics between primary uterine leiomyoma and pulmonary benign metastasizing leiomyoma

PURPOSE

Pulmonary benign metastasizing leiomyoma (PBML), a rare condition of smooth muscle tumor, originates from women with a history of uterine leiomyoma (LM). Numerous genetic studies of uterine LM have been reported; however, there are few cytogenetic and molecular descriptions of PBML. Therefore, molecular subtyping is necessary to understand the pathogenesis of metastasizing sites.

METHODS

Driver gene exon-capture sequencing was performed on one patient's peripheral blood, paraffin samples from primary uterine LM, and lung metastasizing leiomyoma 8 years later.

RESULTS

The results showed that the same missense mutations of BLMH, LRP2, MED12, SMAD2, and UGT1A8 were concurrently mutated in the primary uterine LM and the PBML. Moreover, a splice mutation of PTEN (c.492+1G>A) was uniquely identified in the lung metastasis of the patient.

CONCLUSION

This study indicates that the metastatic lung lesions were derived from the same malignant cell clone of uterine LMs and later acquired the novel driver mutations in the evolution of the tumor. In addition, driver gene sequencing can discriminate somatic driver mutations as biological indicators of potential malignant leiomyoma and can identify pathogenic variation driver mutations, which could be used for individualized therapy.

[Relationship between Myofibril Fragmentation Index and Postmortem Interval]

OBJECTIVES

To study the relationship between myofibril fragmentation index （MFI） of human skeletal muscle and postmortem interval （PMI）.

METHODS

The protein concentrations of human right biceps brachii muscle and right quadriceps femoris muscle were obtained at different PMI, and detected at room temperature by biuret method. The MFI of skeletal muscle at 540 nm was measured by ultraviolet spectrophotometer. Regression analysis was performed with time of death as independent variable （x） and MFI as dependent variable （y）.

RESULTS

In early PMI, the MFI of human skeletal muscle increased obviously according to the prolongation of PMI, and peaking by 12 h and then tended to steady. Within 12 h after death, the regression equations of right biceps brachii muscle and right quadriceps femoris muscle were y=32.660+3.227 x（r=0.987 9） and y=32.380+3.495 x（r=0.983 9）, respectively.

CONCLUSIONS

There's high correlation between MFI and PMI. Combining with forensic practice, MFI can be used for the estimation of early PMI （especially in 12 h）.

Direct observation of the topological spin configurations mediated by the substitution of rare-earth element Y in MnNiGa alloy

The evolution of topological magnetic domains microscopically correlates the dynamic behavior of memory units in spintronic application. Nanometric bubbles with variation of spin configurations have been directly observed in a centrosymmetric hexagonal magnet (Mn_0.5Ni_0.5)₆₅(Ga_1-yY_y)₃₅ (y = 0.01) using Lorentz transmission electron microscopy. Magnetic bubbles instead of biskyrmions are generated due to the enhancement of quality factor Q caused by the substitution of rare-earth element Y. Furthermore, the bubble density and diversified spin configurations are systematically manipulated via combining the electric current with perpendicular magnetic fields. The magnetic bubble lattice at zero field is achieved after the optimized manipulation.

BMI, Waist Circumference and All-Cause Mortality in a Middle-Aged and Elderly Chinese Population

OBJECTIVE

To investigate the association of obesity and all-cause mortality in a sample of middle-aged and elderly population.

DESIGN AND SETTING

Information of participants was collected in the Dongfeng-Tongji study, a perspective cohort study of Chinese occupational population. The main outcome was risk of death after 8.5 years of follow-up.

PARTICIPANTS AND MEASUREMENTS

We examined the association of BMI, waist circumference (WC, and waist-height ratio (WHtR) with all-cause mortality in the Dongfeng-Tongji cohort study (n=26,143). Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality. Area under the receiver operating characteristic curves and net reclassification improvement (NRI) were used to calculate the power of prediction models.

RESULTS

During a mean of 8.5 years of follow-up, 2,246 deaths were identified. There is a U-shaped association of BMI with all-cause mortality in the middle-aged and elderly Chinese population. Compared with individuals with normal BMI, underweight was positively (HR=2.16, 95% CI: 1.73, 2.69) while overweight (HR=0.75, 95% CI: 0.67, 0.84) and obesity (HR=0.67, 95% CI: 0.56, 0.79) were negatively associated with all-cause mortality after adjustment for potential confounders including WC. In contrast, WC (Q5 vs. Q1, HR=1.55, 95% CI: 1.29, 1.86) and WHtR (Q5 vs.Q1, HR=1.69, 95% CI: 1.40, 2.04) were positively associated with mortality after further adjustment for BMI (P trend < 0.001). Addition of both BMI and WC into the all-cause mortality predictive model significantly increased AUC (P =0.0002) and NRI (NRI = 2.57%, P = 0.0007).

CONCLUSIONS

BMI and WC/WHtR were independently associated with all-cause mortality after mutual adjustment. Combination of BMI and WC/WHtR improved the predictive ability of all-cause mortality risk in the middle-aged and elderly population.