Heat exposure and hospitalizations for chronic kidney disease in China: a nationwide time series study in 261 major Chinese cities

Background:Climate change profoundly shapes the population health at the global scale.However,there was still insufficient and inconsistent evidence for the association between heat exposure and chronic kidney disease(CKD).Methods:In the present study,we studied the association of heat exposure with hospitalizations for cause-specific CKD using a national inpatient database in China during the study period of hot season from 2015 to 2018.Standard time-series regression models and random-effects Meta-analysis were developed to estimate the city-specific and national averaged associations at a 7 lag-day span,respectively.Results:A total of 768,129 hospitalizations for CKD was recorded during the study period.The results showed that higher temperature was associated with elevated risk of hospitalizations for CKD,especially in sub-tropical cities.With a 1℃ increase in daily mean temperature,the cumulative relative risks(RR)over lag 0-7 d were 1.008[95% confidence interval(CI)1.003-1.012]for nationwide.The attributable fraction of CKD hospitalizations due to high temperatures was 5.50%.Stronger associations were observed among younger patients and those with obstructive nephropathy.Our study also found that exposure to heatwaves was associated with added risk of hospitalizations for CKD compared to non-heatwave days(RR=1.116,95%CI 1.069-1.166)above the effect of daily mean temperature.Conclusions:Short-term heat exposure may increase the risk of hospitalization for CKD.Our findings provide insights into the health effects of climate change and suggest the necessity of guided protection strategies against the adverse effects of high temperatures.

Mineral and Bone Disorder and Its Association with Cardiovascular Parameters in Chinese Patients with Chronic Kidney Disease

Background：Mineral and bone disorder （MBD）,especially hyperphosphatemia,is an independently risk factor for adverse prognosis in patients with chronic kidney disease （CKD）.However,CKD-MBD among Chinese population was poorly studied.This study aimed to investigate the status of MBD and its association with cardiovascular parameters in Chinese patients with predialysis CKD.Methods：Chinese Cohort Study of Chronic Kidney Disease （C-STRIDE） is a prospective multicenter cohort study involving predialysis CKD patients in China.Markers of MBD,including serum phosphorus,calcium,and intact parathyroid hormone,were measured in baseline samples at the patients＆#39; entry.The association between serum phosphorus and abdominal aortic calcification （AAC）,left ventricular hypertrophy （LVH） were examined by logistic regression models.Results：Altogether 3194 predialysis patients with mean estimated glomerular filtration of 51.8 ± 33.1 ml·min^- 1· 1.73 m^- 2 were included.The proportion of patients with hyperphosphatemia were 2.6%,2.9%,6.8%,and 27.1% in CKD Stages 3a,3b,4,and 5,respectively.Moreover,71.6% of the patients with hyperphosphatemia did not receive any phosphate-binder （PB）.Lateral abdominal X-rays were obtained in 2280 patients,9.8% of the patients were diagnosed as having AAC.Altogether 2219 patients had data of echocardiography,and 13.2% of them were diagnosed with LVH.Multivariate logistic regression analysis showed that serum phosphorus was independently associated with the presence of AAC and LVH.Conclusions：In Chinese patients with CKD,the percentage of hyperphosphatemia is comparable to that of other countries while the usage of PBs is suboptimal.The prevalence of vascular calcification in Chinese patients is relatively lower compared with the Caucasian population.

ncidence, Development, and Prognosis of Diabetic Kidney Disease in China： Design and Methods

Background： Although that glomerulonephritis is the major cause of end-stage renal disease in developing countries such as China, the increasing prevalence of diabetes has contributed to the changing spectrum of predialysis chronic kidney disease. Recent studies have revealed an increased proportion of patients with diabetic kidney disease （DKD） in hemodialysis populations in large cities in China. However, studies regarding the clinical phenotype of DKD in China are extremely limited. The incidence, development, and prognosis of diabetic kidney disease （INDEED） study aims to investigate the incidence, progression, and prognosis of DKD, as well as the associated genetic, behavioral, and environmental factors and biomarkers in patients with DKD in China. Methods： INDEED study is a prospective cohort study based on all participants with diabetes in the Kailuan study, which is a general population-based cohort study in northern China. Altogether, over 10,000 participants with diabetes will be followed biennially. Questionnaires documenting general characteristics, behavioral and environmental factors, and medical history will be administrated. Anthropometric measurements and a series of laboratory tests will be peribrmed in one central laboratory. The DNA, plasma, and urine samples of every participant will be stored in a biobank for future research. Conclusions： INDEED study will provide essential information regarding the clinical phenotype and prognosis of patients with DKD in China and will be valuable to identity factors and biomarkers associated with patients with DKD in China.

Association between serum uric acid level and mortality in China

Background:Whether there is an association between serum uric acid(SUA)level and risk of mortality in the general population remains unclear.Based on the China National Survey of Chronic Kidney Disease linked to mortality data,a population-based cohort study was performed to investigate the association between SUA level and all-cause mortality,cardiovascular disease(CVD)mortality,and cancer mortality in China.Methods:The survival status of participants in the cross-sectional survey was identified from January 1,2006 to December 31,2017.Only 33,268 individuals with complete SUA data among the 47,204 participants were included in the analysis.We determined the rates of all-cause mortality,CVD mortality,and cancer mortality.We used Cox proportional hazards regression models to evaluate the effect of the SUA level on mortality.Results:During a total of 297,538.4 person-years of follow-up,1282 deaths occurred.In the Cox proportional hazards regression model,the rate of all-cause mortality,CVD mortality,and cancer mortality had a U-shaped association with SUA levels only in men,whereas no significant associations were detected in women.For all-cause mortality in men,the multivariable-adjusted hazard ratios(HRs)in the first,second,and fourth quartiles compared with the third quartile were 1.31(95%confidence interval[CI]1.04–1.67),1.17(95%CI 0.92–1.47),and 1.55(95%CI 1.24–1.93),respectively.For CVD mortality,the corresponding HRs were 1.47(95%CI 1.00–2.18),1.17(95%CI 0.79–1.75),and 1.67(95%CI 1.16–2.43),respectively.For the cancer mortality rate,only a marginally significant association was detected in the fourth quartile compared with the third quartile with an HR of 1.43(95%CI 0.99–2.08).Conclusions:The association between SUA and mortality differed by sex.We demonstrated a U-shaped association with SUA levels for all-cause and CVD mortalities among men in China.