Objective To explore time-related changes in renal function,renal injury biomarkers,and renal pathology in rats entering a low-pressure and low-oxygen(LPLO)environment simulating moving from the plains to a plateau.Methods Thirty male Sprague-Dawley rats were divided randomly into five groups(n=6 rats per group).Rats in the Control group were placed outside the chamber under normal pressure and oxygen conditions.Rats in the experimental groups were placed in an LPLO chamber to simulate a plateau environment at 5000 m above sea level,and were maintained in the chamber for 3,7,14,and 28 days,respectively.Serum levels of creatinine(CRE),cystatin C(CysC),neutrophil gelatinase-associated lipocalin(NGAL),kidney injury molecule-1(KIM-1),and interleukin-18(IL-18)were measured as biomarkers of renal injury.Pathological changes in the kidney were observed by hematoxylin and eosin and periodic acid-Schiff staining,with quantitative assessment of the following parameters:average glomerular diameter,peritubular capillary(PTC)density per tubule,tubular injury score,and outer medulla(OM)congestion score.Results NGAL,KIM-1,CysC,and CRE were significantly increased in the experimental compared with the Control group(all P＜0.05).The average glomerulus diameter was significantly reduced in the LPLO 3 d group and significantly increased in the LPLO 14 d group(both P＜0.05).The peritubular capillary(PTC)/tubule ratio was significantly decreased.The renal tubular injury and OM congestion scores were significantly increased(both P＜0.05).Regression analysis showed that PTC/tubule was linearly negatively correlated with the LPLO duration,while CRE,CysC,and pathological indicators(mean glomerular diameter,OM congestion score,renal tubular injury score)were curvilinearly correlated with the duration of LPLO(all P＜0.05).Variables with a curvilinear correlation were analyzed using restricted cubic splines(RCS).Each curve exhibited an inverted-L shape,with inflection points on day 7,indicating that the rate of increase of all indicators was highest within the first 7 days of LPLO,and the rate of increase then slowed from 7 days to 28 days.Conclusions A simulated move from a plains to a plateau environment was associated with significant structural and functional renal damage,but the kidneys then showed a self-adaptive adjustment process towards the plateau environment.

Objective:To investigate the effect of intradialytic cerebral blood flow (CBF) fluctuation on cognitive decline in middle-aged and elderly maintenance hemodialysis (MHD) patients.Methods:It was a prospective cohort study. MHD patients aged ≥50 years from Beijing Shijitan Hospital were enrolled from January 2023 to June 2023. Middle cerebral artery mean flow velocity (MFV) was serially monitored via transcranial Doppler (TCD) during dialysis sessions. Cognitive function was assessed at baseline and after 12-month follow-up using standardized neuropsychological tests: montreal cognitive assessment (MoCA), auditory verbal learning test (AVLT 5), complex figure test (CFT), trail making test-B (TMT-B), Stroop color and word test (SCWT), and symbol digit modalities test (SDMT). ΔMFV was calculated as pre-to-post dialysis MFV difference. Multivariable linear regression was used to analyze the association of ΔMFV and cognition.Results:A total of 121 MHD patients were recruited with an age of (63.63±8.44) years. There were 97 males (80.2%), and the dialysis vintage was (55.08±54.73) months. Significant intradialytic MFV reductions were observed ( P<0.05). At 12 months, cognitive decline manifested in global cognition (MoCA), memory (CFT-memory), executive function (TMT-B, SCWT-C, SCWT-T), attention (SDMT), visuospatial ability (CFT-copy)(all P<0.05). Multivariable linear regression analysis revealed ΔMFV independently predicted declines in: MoCA ( B=0.066, 95% CI 0.018-0.113, P=0.007), AVLT5 ( B=0.050, 95% CI 0.004-0.097, P=0.035), TMT-B ( B=-1.955, 95% CI -3.453--0.457, P=0.011), SCWT-C ( B=0.298, 95% CI 0.112-0.484, P=0.002), SCWT-T ( B=-1.371, 95% CI -2.303--0.439, P=0.004). Conclusions:Hemodialysis induces acute CBF reductions detectable by TCD. Cumulative intradialytic CBF fluctuations may accelerate cognitive deterioration in middle-aged and elderly MHD populations, particularly affecting memory and executive domains.

Objective To explore time-related changes in renal function,renal injury biomarkers,and renal pathology in rats entering a low-pressure and low-oxygen(LPLO)environment simulating moving from the plains to a plateau.Methods Thirty male Sprague-Dawley rats were divided randomly into five groups(n=6 rats per group).Rats in the Control group were placed outside the chamber under normal pressure and oxygen conditions.Rats in the experimental groups were placed in an LPLO chamber to simulate a plateau environment at 5000 m above sea level,and were maintained in the chamber for 3,7,14,and 28 days,respectively.Serum levels of creatinine(CRE),cystatin C(CysC),neutrophil gelatinase-associated lipocalin(NGAL),kidney injury molecule-1(KIM-1),and interleukin-18(IL-18)were measured as biomarkers of renal injury.Pathological changes in the kidney were observed by hematoxylin and eosin and periodic acid-Schiff staining,with quantitative assessment of the following parameters:average glomerular diameter,peritubular capillary(PTC)density per tubule,tubular injury score,and outer medulla(OM)congestion score.Results NGAL,KIM-1,CysC,and CRE were significantly increased in the experimental compared with the Control group(all P＜0.05).The average glomerulus diameter was significantly reduced in the LPLO 3 d group and significantly increased in the LPLO 14 d group(both P＜0.05).The peritubular capillary(PTC)/tubule ratio was significantly decreased.The renal tubular injury and OM congestion scores were significantly increased(both P＜0.05).Regression analysis showed that PTC/tubule was linearly negatively correlated with the LPLO duration,while CRE,CysC,and pathological indicators(mean glomerular diameter,OM congestion score,renal tubular injury score)were curvilinearly correlated with the duration of LPLO(all P＜0.05).Variables with a curvilinear correlation were analyzed using restricted cubic splines(RCS).Each curve exhibited an inverted-L shape,with inflection points on day 7,indicating that the rate of increase of all indicators was highest within the first 7 days of LPLO,and the rate of increase then slowed from 7 days to 28 days.Conclusions A simulated move from a plains to a plateau environment was associated with significant structural and functional renal damage,but the kidneys then showed a self-adaptive adjustment process towards the plateau environment.

Objective:To investigate the effect of intradialytic cerebral blood flow (CBF) fluctuation on cognitive decline in middle-aged and elderly maintenance hemodialysis (MHD) patients.Methods:It was a prospective cohort study. MHD patients aged ≥50 years from Beijing Shijitan Hospital were enrolled from January 2023 to June 2023. Middle cerebral artery mean flow velocity (MFV) was serially monitored via transcranial Doppler (TCD) during dialysis sessions. Cognitive function was assessed at baseline and after 12-month follow-up using standardized neuropsychological tests: montreal cognitive assessment (MoCA), auditory verbal learning test (AVLT 5), complex figure test (CFT), trail making test-B (TMT-B), Stroop color and word test (SCWT), and symbol digit modalities test (SDMT). ΔMFV was calculated as pre-to-post dialysis MFV difference. Multivariable linear regression was used to analyze the association of ΔMFV and cognition.Results:A total of 121 MHD patients were recruited with an age of (63.63±8.44) years. There were 97 males (80.2%), and the dialysis vintage was (55.08±54.73) months. Significant intradialytic MFV reductions were observed ( P<0.05). At 12 months, cognitive decline manifested in global cognition (MoCA), memory (CFT-memory), executive function (TMT-B, SCWT-C, SCWT-T), attention (SDMT), visuospatial ability (CFT-copy)(all P<0.05). Multivariable linear regression analysis revealed ΔMFV independently predicted declines in: MoCA ( B=0.066, 95% CI 0.018-0.113, P=0.007), AVLT5 ( B=0.050, 95% CI 0.004-0.097, P=0.035), TMT-B ( B=-1.955, 95% CI -3.453--0.457, P=0.011), SCWT-C ( B=0.298, 95% CI 0.112-0.484, P=0.002), SCWT-T ( B=-1.371, 95% CI -2.303--0.439, P=0.004). Conclusions:Hemodialysis induces acute CBF reductions detectable by TCD. Cumulative intradialytic CBF fluctuations may accelerate cognitive deterioration in middle-aged and elderly MHD populations, particularly affecting memory and executive domains.

Objective:To analyze the clinical characteristics and risk factors of acute kidney injury (AKI) in portal venous hypertension patients undergoing transjugular intrahepatic portosystemic shunt (TIPS).Methods:It was a retrospective observational study. In this study, the clinical data of portal venous hypertension patients undergoing TIPS at Beijing Shijitan Hospital, Capital Medical University from October 16, 2020 to March 30, 2022 were collected retrospectively. According to the Kidney Disease: Improving Global Outcomes (KDIGO) definition of AKI, patients were divided into AKI group and non-AKI group. The clinical characteristics of the patients were compared between the two groups, and multivariate logistic regression was used to analyze the risk factors of AKI.Results:A total of 384 patients undergoing TIPS were included in this study, whose age was (53.17±13.35) years. Among them, 122 (31.8%) were female, and 32 patients (8.3%) had AKI. Compared to the non-AKI group, the proportion of patients with diabetes mellitus, baseline estimated glomerular filtration rate (eGFR) <60 ml·min -1·(1.73 m 2) -1 and intraoperative hypotension, Child-Pugh score of liver function, preoperative serum creatinine, preoperative blood uric acid, and postoperative portal venous pressure gradient (PPG) were higher in AKI group (all P<0.05), while the levels of hemoglobin and serum albumin were lower (both P<0.05). Multivariate logistic regression results showed that combined diabetes ( OR=3.728, 95% CI 1.262-11.013, P=0.017), baseline eGFR<60 ml·min -1·(1.73 m 2) -1( OR=3.571, 95% CI 1.356-9.400, P=0.010), decreased serum albumin ( OR=0.847, 95% CI 0.738-0.972, P=0.018), increased PPG after TIPS ( OR=1.096, 95% CI 1.002-1.200, P=0.045) and intraoperative hypotension ( OR=7.006, 95% CI 2.023-24.195, P=0.002) were independently associated with postoperative AKI in portal venous hypertension patients undergoing TIPS. Until discharge, 6 patients with AKI (18.8%) had complete renal function recovery, 24 patients (75.0%) partially recovered, and 2 patients (6.3%) did not recover. The length of hospital stay, hospitalization costs, and all-cause mortality in AKI patients were significantly higher than those in the non-AKI group ( P<0.05, respectively). Conclusions:AKI is not uncommon in patients receiving TIPS. The classical risk factors of AKI, such as diabetes and baseline renal dysfunction, and the factors affecting volumes like lower serum albumin level, hypotension during the operation, and higher PPG level are closely related to the incidence of AKI in these patients. AKI significantly increases the all-cause mortality and medical expenses, which is worth early prevention and treatment by clinicians.

Objective:To investigate the changes and associated factors of cerebral blood flow in middle-aged and elderly patients undergoing maintenance hemodialysis (MHD).Methods:This was a prospective observational study. End-stage renal disease (ESRD) patients undergoing MHD aged over 50 years at Beijing Shijitan Hospital, Capital Medical University from January 2023 to June 2023 were included. General clinical data of the selected individuals were collected, and dialysis related indicators were recorded and calculated. Mean flow velocity (MFV) of the middle cerebral arterial was measured by transcranial Doppler sonography (TCD) to represent cerebral blood flow throughout dialysis. Hemodialysis-related variables were collected. The MFV values of bilateral middle cerebral artery were measured through temporal windows at 7 time points: 15 minutes before dialysis (T1), 15 minutes (T2), 30 minutes (T3), 60 minutes (T4), 120 minutes (T5), 180 minutes (T6) during dialysis, and the endpoint of dialysis (T7), and the average values were recorded. The ΔMFV was calculated as pre-minus endpoint values of MFV. The Spearman rank correlation method was used to analyze the correlations between ΔMFV and dialysis-related variables, and multiple linear regression method was used to analyze the related factors of the changes in MFV.Results:This study included a total of 123 patients undergoing MHD, aged (63.63±8.44) years (range 50-85 years), including 99 males (80.5%). TCD examination demonstrated a decline trend in MFV throughout dialysis. The MFV at T7 was significantly lower than that at T1 ( Z=-7.650, P<0.001). The Spearman correlation analysis showed that the decline in MFV was correlated with ultrafiltration volume ( r=0.356), ultrafiltration rate ( r=0.371), the difference in systolic pressure (pre-analysis minus post-dialysis, r=0.251), the difference in mean arterial pressure (pre-dialysis minus post-dialysis, r=0.194), combined diabetes ( r=0.293), dialysis vintage ( r=0.220), Kt/V ( r=0.287), and serum albumin ( r=-0.295). Multiple linear regression analysis showed that combined with diabetes ( B=3.889, 95% CI 1.373-6.405, P=0.003), decreased serum albumin ( B=-0.456, 95% CI -0.877--0.036, P=0.034), increased ultrafiltration rate ( B=11.099, 95% CI 6.402-15.797, P<0.001) and the decline in systolic pressure ( B=0.062, 95% CI 0.008-0.116, P=0.026) were significantly associated with the decline in MFV throughout dialysis. Conclusions:In middle and elderly patients with ESRD undergoing hemodialysis, there is a decline trend in cerebral blood flow during hemodialysis. The combination of diabetes, lower serum albumin, higher ultrafiltration rate, and intradialytic systolic pressure decline are the risk factors influencing the intradialytic decline of cerebral blood flow.

Objective To explore the relationship between hyperkalemia and adverse outcomes in elderly maintenance hemodialysis(MHD)patients.Methods A retrospective cohort trial was conducted on 177 MHD patients aged≥60 years in the hemodialysis center of Beijing Shijitan Hospital,Capital Medical University.Baseline data were collected.The mean age was(77.28±14.25)years,among them 109 cases were males(61.6%).According to the peak serum potassium within 4 months,patients were divided into the K+＜5.0 mmol/L group(38 cases,21.5%),the 5.0-5.5 mmol/L group(42 cases,23.7%)and the K+≥5.5 mmol/L group(97 cases,54.8%).Based on the frequency of hyperkalemia within 4 months,patients were divided into the 0,1-2 and 3-4 frequency groups.All of patients were followed up for 1 year.The end point events were all-cause mortality and cardiovascular disease(CVD)mortality.Kaplan-Meier survival analysis was used to compare the cumulative survival rate between the 3 groups.A multivariate Cox regression model was employed to analyze the relationship between the degree and frequency of hyperkalemia with all-cause and CVD mortality.Results The mean follow-up time of 177 patients was 12(1-12)months,20(11.3%)patients died of all-cause death and 14(7.9%)of CVD death.Kaplan Meier survival curve showed cardiovascular mortality rate and all-cause mortality were significantly increased in the K+5.0-5.5 mmol/L group and the K+≥5.5 mmol/L group(both P＜0.05).Multivariate Cox regression analysis indicated that,as a continuous variable,peak potassium levels were independently associated with an increased risk of all-cause death and CVD death(P＜0.001).As a categorical variable,the all-cause mortality risk and CVD mortality risk were significantly higher in both the K+5.0-5.5 mmol/L group and the K+≥5.5 mmol/L group than those in the K+＜5.0 mmol/L group(P＜0.05),and those were significantly higher in the 1-2 and 3-4 frequency groups than those in the 0 frequency group of hyperkalemia(P＜0.05).Conclusion Serum potassium>5.0 mmol/L in elderly MHD patients is an independent risk factor for all-cause and CVD mortality.It is recommended to adjust the upper limit of the normal range of serum potassium to 5.0 mmol/L.

Objective This study aimed to explore the relationships between residential greenness and cardiometabolic risk factors among rural adults in Xinjiang Uygur Autonomous Region(Xinjiang)and thus provide a theoretical basis and data support for improving the health of residents in this region. Methods We recruited 9,723 adult rural residents from the 51st Regiment of the Third Division of the Xinjiang Production and Construction Corps in September 2016.The normalized difference vegetation index(NDVI)was used to estimate residential greenness.The generalized linear mixed model(GLMM)was used to examine the association between residential greenness and cardiometabolic risk factors. Results Higher residential greenness was associated with lower cardiometabolic risk factor prevalence.After adjustments were made for age,sex,education,and marital status,for each interquartile range(IQR)increase of NDVI500-m,the risk of hypertension was reduced by 10.3%(OR=0.897,95%CI=0.836-0.962),the risk of obesity by 20.5%(OR=0.795,95%CI=0.695-0.910),the risk of type 2 diabetes by 15.1%(OR=0.849,95%CI=0.740-0.974),and the risk of dyslipidemia by 10.5%(OR=0.895,95%CI=0.825-0.971).Risk factor aggregation was reduced by 20.4%(OR=0.796,95%CI=0.716-0.885)for the same.Stratified analysis showed that NDVI500-m was associated more strongly with hypertension,dyslipidemia,and risk factor aggregation among male participants.The association of NDVI500-m with type 2 diabetes was stronger among participants with a higher education level.PM10 and physical activity mediated 1.9%-9.2%of the associations between NDVI500-m and obesity,dyslipidemia,and risk factor aggregation. Conclusion Higher residential greenness has a protective effect against cardiometabolic risk factors among rural residents in Xinjiang.Increasing the area of green space around residences is an effective measure to reduce the burden of cardiometabolic-related diseases among rural residents in Xinjiang.

Objective To explore the relationship between geriatric nutritional risk index(GNRI)and adverse outcomes in elderly patients undergoing maintenance hemodialysis(MHD).Methods A prospective cohort trial was conducted on 337 MHD patients aged ≥60 years in hemodialysis centers of 11 hospitals in Beijing from April to June 2017.Their baseline data were collected,and they were divided into non-malnutrition(GNRI≥98,226 cases),mild malnutrition(92≤GNRI＜98,81 cases),and major malnutrition groups(GNRI＜92,30 cases).All of them were followed up until June 2018.The endpoint events were all-cause mortality and cardiovascular disease(CVD)mortality.Kaplan-Meier survival analysis was used to compare the cumulative survival rate among the 3 groups.Multivariate Cox regression model was employed to analyze the relationship of GNRI with all-cause and CVD mortality.Results The mild and major malnutrition groups had significantly lower BMI,serum albumin level and GNRI(P＜0.01).During the median follow-up of 52(4.4-52.0)weeks,56(16.6％)patients died of all-cause death and 25(44.6％)of CVD death.Kaplan-Meier survival curve showed significant differences in all-cause mortality(x2=30.484,P＜0.01)and CVD mortality(x2=22.398,P＜0.01)in the 3 groups.Multivariate Cox regression analysis indicated that,as a continuous variable,elevated GNRI was a protective factor for all-cause mortality(HR=0.910,95％CI:0.870-0.952,P=0.000)and CVD mortality(HR=0.895,95％CI:0.852-0.940,P=0.000),and as a categorical variable,mild and major malnutri-tion were independently correlated with all-cause and CVD mortality(P＜0.05).Conclusion GNRI is an independent risk factor for all-cause and CVD mortality in elderly MHD patients.Mo-nitoring the nutritional status using GNRI can predict the risk of adverse prognosis.