Summary Background The prevalence of chronic kidney disease is high in developing countries. However, no national survey of chronic kidney disease has been done incorporating both estimated ...glomerular filtration rate (eGFR) and albuminuria in a developing country with the economic diversity of China. We aimed to measure the prevalence of chronic kidney disease in China with such a survey. Methods We did a cross-sectional survey of a nationally representative sample of Chinese adults. Chronic kidney disease was defined as eGFR less than 60 mL/min per 1·73 m2 or the presence of albuminuria. Participants completed a lifestyle and medical history questionnaire and had their blood pressure measured, and blood and urine samples taken. Serum creatinine was measured and used to estimate glomerular filtration rate. Urinary albumin and creatinine were tested to assess albuminuria. The crude and adjusted prevalence of indicators of kidney damage were calculated and factors associated with the presence of chronic kidney disease analysed by logistic regression. Findings 50 550 people were invited to participate, of whom 47 204 agreed. The adjusted prevalence of eGFR less than 60 mL/min per 1·73 m2 was 1·7% (95% CI 1·5–1·9) and of albuminuria was 9·4% (8·9–10·0). The overall prevalence of chronic kidney disease was 10·8% (10·2–11·3); therefore the number of patients with chronic kidney disease in China is estimated to be about 119·5 million (112·9–125·0 million). In rural areas, economic development was independently associated with the presence of albuminuria. The prevalence of chronic kidney disease was high in north (16·9% 15·1–18·7) and southwest (18·3% 16·4–20·4) regions compared with other regions. Other factors independently associated with kidney damage were age, sex, hypertension, diabetes, history of cardiovascular disease, hyperuricaemia, area of residence, and economic status. Interpretation Chronic kidney disease has become an important public health problem in China. Special attention should be paid to residents in economically improving rural areas and specific geographical regions in China. Funding The Ministry of Science and Technology (China); the Science and Technology Commission of Shanghai; the National Natural Science Foundation of China; the Department of Health, Jiangsu Province; the Sichuan Science and Technology Department; the Ministry of Education (China); the International Society of Nephrology Research Committee; and the China Health and Medical Development Foundation.
Summary Background Hypertension is the most prevalent comorbidity in individuals with chronic kidney disease. However, whether the association of the kidney disease measures, estimated glomerular ...filtration rate (eGFR) and albuminuria, with mortality or end-stage renal disease (ESRD) differs by hypertensive status is unknown. Methods We did a meta-analysis of studies selected according to Chronic Kidney Disease Prognosis Consortium criteria. Data transfer and analyses were done between March, 2011, and June, 2012. We used Cox proportional hazards models to estimate the hazard ratios (HR) of mortality and ESRD associated with eGFR and albuminuria in individuals with and without hypertension. Findings We analysed data for 45 cohorts (25 general population, seven high-risk, and 13 chronic kidney disease) with 1 127 656 participants, 364 344 of whom had hypertension. Low eGFR and high albuminuria were associated with mortality irrespective of hypertensive status in the general population and high-risk cohorts. All-cause mortality risk was 1·1–1·2 times higher in individuals with hypertension than in those without hypertension at preserved eGFR. A steeper relative risk gradient in individuals without hypertension than in those with hypertension at eGFR range 45–75 mL/min per 1·73 m2 led to much the same mortality risk at lower eGFR. With a reference eGFR of 95 mL/min per 1·73 m2 in each group to explicitly assess interaction, adjusted HR for all-cause mortality at eGFR 45 mL/min per 1·73 m2 was 1·77 (95% CI 1·57–1·99) in individuals without hypertension versus 1·24 (1·11–1·39) in those with hypertension (p for overall interaction=0·0003). Similarly, for albumin-creatinine ratio of 300 mg/g ( vs 5 mg/g), HR was 2·30 (1·98–2·68) in individuals without hypertension versus 2·08 (1·84–2·35) in those with hypertension (p for overall interaction=0·019). We recorded much the same results for cardiovascular mortality. The associations of eGFR and albuminuria with ESRD, however, did not differ by hypertensive status. Results for chronic kidney disease cohorts were similar to those for general and high-risk population cohorts. Interpretation Chronic kidney disease should be regarded as at least an equally relevant risk factor for mortality and ESRD in individuals without hypertension as it is in those with hypertension. Funding US National Kidney Foundation.
Background Recent studies have indicated that phosphorus may play an independent pathogenic role in chronic kidney disease (CKD) progression, but some of those studies were underpowered and yielded ...inconsistent results. Study Design Systematic review and meta-analysis. Setting & Population Non–dialysis-dependent patients with CKD (transplant recipients were excluded). Selection Criteria for Studies Studies assessing the risk ratio of serum phosphorus level on kidney failure and mortality for non–dialysis-dependent patients with CKD published from January 1950 to June 2014 were included following systematic searching of MEDLINE, EMBASE, and the Cochrane Library. Predictor Serum phosphorus level. Outcome Kidney failure, defined as doubled serum creatinine level, 50% decline in estimated glomerular filtration rate, or end-stage kidney disease. Results In 12 cohort studies with 25,546 patients, 1,442 (8.8%) developed kidney failure and 3,089 (13.6%) died. Overall, every 1-mg/dL increase in serum phosphorus level was associated independently with increased risk of kidney failure (hazard ratio, 1.36; 95% CI, 1.20-1.55) and mortality (hazard ratio, 1.20; 95% CI, 1.05-1.37). Limitations Existence of potential residual confounding could not be excluded. Conclusions This meta-analysis suggests an independent association between serum phosphorus level and kidney failure and mortality among non–dialysis-dependent patients with CKD and suggests that large-scale randomized controlled trials should target disordered phosphorus homeostasis in CKD.
Background Chronic kidney disease (CKD) is considered a serious worldwide public health problem, but data from developing countries are extremely limited. Study Design Cross-sectional study. Setting ...and Participants A representative sample of 13,925 adults in Beijing, China. Predictors Age (18 to 39, 40 to 59, 60 to 69, and >70 years), sex, urban or rural area, history of chronic respiratory infection and cardiovascular disease, hepatitis B virus infection, smoking, family history (diabetes, hypertension, and CKD), nephrotoxic medications, central obesity, diabetic and hypertension status, and dyslipidemia. Outcomes and Measurements CKD was defined as estimated glomerular filtration rate less than 60 mL/min/1.73 m2 or markers of kidney damage. Glomerular filtration rate was estimated by using calibrated serum creatinine level and a formula specific for China. Persistent albuminuria and hematuria were considered markers of kidney damage. Results The prevalence of CKD in adults in Beijing was 13.0% (95% confidence interval CI, 11.9 to 14.2). It therefore was estimated that the number of adults in Beijing with CKD was 1.43 million. In subjects aged 18 to 39, 40 to 59, 60 to 69, and older than 70 years, prevalences of CKD were 10.0% (95% CI, 8.9 to 11.3), 14.2% (95% CI, 13.0 to 15.4), 20.8% (95% CI, 18.1 to 23.9), and 30.5% (95% CI, 26.6 to 34.7), respectively. Factors independently associated with decreased kidney function included older age (odds ratio OR, 1.83; 95% CI, 1.51 to 2.22 per 10-year increase), nephrotoxic medications (OR, 2.19; 95% CI, 1.21 to 3.97), rural area (versus urban area; OR, 0.47; 95% CI, 0.28 to 0.78), history of cardiovascular disease (OR, 2.04; 95% CI, 1.24 to 3.38), high-density lipoprotein cholesterol level less than 40 mg/dL (OR, 3.00; 95% CI, 1.39 to 6.51), and hypertension status (with duration > 10 years; OR, 1.85; 95% CI, 1.19 to 2.88). Limitations Kidney function and indicators of kidney damage were based on single measurements. Conclusions CKD is a public health burden in Beijing.
Background Long-term intake of herbs containing aristolochic acid (AA) has been reported to be associated with increased risk of chronic kidney disease (CKD), whereas population-based studies are ...limited. Study Design Cross-sectional study. Setting & Participants A national representative sample of 47,204 adults in China. Predictor Self-reported long-term use of medications containing AA. Outcomes & Measurements CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 and/or the presence of albuminuria, defined as albumin-creatinine ratio >30 mg/g. Results 467 participants reported long-term AA intake, with a prevalence adjusting for a synthesized weight of 1.5% (95% CI, 1.2%-1.7%). After adjusting for age, sex, and other potential confounders, long-term AA intake was associated with eGFR <60 mL/min/1.73 m2 and albuminuria, with ORs of 1.83 (95% CI, 1.22-2.74) and 1.39 (95% CI, 1.03-1.87), respectively. Further adjustment for intake of nonsteroidal anti-inflammatory drugs did not change ORs substantially. A positive association between accumulated time of AA intake and kidney disease also was observed, with fully adjusted ORs of 1.07 (95% CI, 1.03-1.12) per 6-month longer intake for eGFR <60 mL/min/1.73 m2 and 1.04 (95% CI, 1.01-1.08) per 6-month longer intake for albuminuria. Limitations Self-reported intake of herbs containing AA; the AA content of the preparations by weight was unknown; single measurement of indicators of kidney damage. Conclusions Long-term intake of medications containing AA is prevalent in China and is associated with the presence of CKD.
Summary Background Chronic kidney disease is an important cause of global mortality and morbidity. Data for epidemiological features of chronic kidney disease and its risk factors are limited for ...low-income and middle-income countries. The International Society of Nephrology's Kidney Disease Data Center (ISN-KDDC) aimed to assess the prevalence and awareness of chronic kidney disease and its risk factors, and to investigate the risk of cardiovascular disease, in countries of low and middle income. Methods We did a cross-sectional study in 12 countries from six world regions: Bangladesh, Bolivia, Bosnia and Herzegovina, China, Egypt, Georgia, India, Iran, Moldova, Mongolia, Nepal, and Nigeria. We analysed data from screening programmes in these countries, matching eight general and four high-risk population cohorts collected in the ISN-KDDC database. High-risk cohorts were individuals at risk of or with a diagnosis of either chronic kidney disease, hypertension, diabetes, or cardiovascular disease. Participants completed a self-report questionnaire, had their blood pressure measured, and blood and urine samples taken. We defined chronic kidney disease according to modified KDIGO (Kidney Disease: Improving Global Outcomes) criteria; risk of cardiovascular disease development was estimated with the Framingham risk score. Findings 75 058 individuals were included in the study. The prevalence of chronic kidney disease was 14·3% (95% CI 14·0–14·5) in general populations and 36·1% (34·7–37·6) in high-risk populations. Overall awareness of chronic kidney disease was low, with 409 (6%) of 6631 individuals in general populations and 150 (10%) of 1524 participants from high-risk populations aware they had chronic kidney disease. Moreover, in the general population, 5600 (44%) of 12 751 individuals with hypertension did not know they had the disorder, and 973 (31%) of 3130 people with diabetes were unaware they had that disease. The number of participants at high risk of cardiovascular disease, according to the Framingham risk score, was underestimated compared with KDIGO guidelines. For example, all individuals with chronic kidney disease should be considered at high risk of cardiovascular disease, but the Framingham risk score detects only 23% in the general population, and only 38% in high-risk cohorts. Interpretation Prevalence of chronic kidney disease was high in general and high-risk populations from countries of low and middle income. Moreover, awareness of chronic kidney disease and other non-communicable diseases was low, and a substantial number of individuals who knew they were ill did not receive treatment. Prospective programmes with repeat testing are needed to confirm the diagnosis of chronic kidney disease and its risk factors. Furthermore, in general, health-care workforces in countries of low and middle income need strengthening. Funding International Society of Nephrology.
Background Increased carotid artery intima-media thickness (IMT) predicts future vascular events in the general population. However, the relationship between IMT and chronic kidney disease (CKD) ...seldom was tested in subjects with early-stage CKD. Study Design Cross-sectional study. Setting & Participants 1,046 residents in 1 district of Beijing participated in the study. Outcomes & Measurements Carotid artery IMT was measured by means of high-resolution B-mode ultrasonography. Estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease Study equation based on data for Chinese patients with CKD. Albuminuria was evaluated by means of urinary albumin-creatinine ratio on a morning spot urine sample. Results Compared with subjects with eGFR greater than 90 mL/min/1.73 m2 (>1.50 mL/s/1.73 m2 ), subjects with eGFR of 60 to 89 mL/min/1.73 m2 (1.00 to 1.49 mL/s/1.73 m2 ) and 30 to 59 mL/min/1.73 m2 (0.50 to 0.99 mL/s/1.73 m2 ) had higher mean IMT (0.74 ± 0.27 versus 0.82 ± 0.30 versus 0.94 ± 0.38 mm; P < 0.001). IMTs of subjects with albuminuria tended to be higher than the mean value (0.79 ± 0.29 versus 0.93 ± 0.38 mm; P < 0.001). eGFR and urinary albumin-creatinine ratio significantly correlated with IMT in univariable analysis, but not after adjusting for traditional cardiovascular disease risk factors. Limitations Selection bias and low prevalence of CKD might affect the strength of the study. Conclusions In this Chinese population older than 40 years, carotid artery IMT was significantly higher in subjects with early-stage CKD. The greater prevalence of cardiovascular disease risk factors in patients with CKD appeared to account for the higher carotid artery IMT.
Chronic kidney disease is growing as a global public health problem. With more than 1.3 billion people, China is the world's largest and most populous country. Understanding the epidemiology of ...chronic kidney disease in China could be helpful to predict its impact on the health care system and to establish comprehensive strategies to reduce its burden.