Prevalence and risk factors of chronic kidney disease: a population study in the Tibetan population

Intermittent high altitude hypoxia induced liver and kidney injury leading to hyperuricemia

About 140 million people worldwide live at an altitude above 2500 m. Studies have showed an increase of the incidence of hyperuricemia among plateau populations, but little is known about the possible mechanisms. This study aims to assess the effects of high altitude on hyperuricemia and explore the corresponding mechanisms at the histological, inflammatory and molecular levels. This study finds that intermittent hypobaric hypoxia (IHH) exposure results in an increase of serum uric acid level and a decrease of uric acid clearance rate. Compared with the control group, the IHH group shows significant increases in hemoglobin concentration (HGB) and red blood cell counts (RBC), indicating that high altitude hyperuricemia is associated with polycythemia. This study also shows that IHH exposure induces oxidative stress, which causes the injury of liver and renal structures and functions. Additionally, altered expressions of organic anion transporter 1 (OAT1) and organic cation transporter 1 (OCT1) of kidney have been detected in the IHH exposed rats. The adenosine deaminase (ADA) expression levels and the xanthione oxidase (XOD) and ADA activity of liver of the IHH exposure group have significantly increased compared with those of the control group. Furthermore, the spleen coefficients, IL-2, IL-1β and IL-8, have seen significant increases among the IHH exposure group. TLR/MyD88/NF-κB pathway is activated in the process of IHH induced inflammatory response in joints. Importantly, these results jointly show that IHH exposure causes hyperuricemia. IHH induced oxidative stress along with liver and kidney injury, unusual expression of the uric acid synthesis/excretion regulator and inflammatory response, thus suggesting a potential mechanism underlying IHH-induced hyperuricemia.

A Case of High-Altitude Renal Syndrome

Wang, Si-Yang, Jun Liang, and Jing-Hong Zhao. A Case of High-Altitude Renal Syndrome. High Alt Med Biol. 00:000-000, 2024.-Epidemiological studies have confirmed that high-altitude exposure increases the risk of proteinuria. The concept of high-altitude renal syndrome (HARS) was proposed in 2011. HARS is a group of clinical syndromes consisting of high-altitude polycythemia, hyperuricemia, systemic hypertension, and microalbuminuria. At present, no standardized and unified treatment methods of HARS have been proposed. We report a case of HARS without other organ involvement in a young man exposed to high altitude. Decreasing the red blood cell count and hemodynamic changes as soon as possible may be of great importance for reducing proteinuria. In addition, angiotensin receptor blockers are effective in the treatment of HARS.

Prevalence of High-Altitude Polycythemia and Hyperuricemia and Risk Factors for Hyperuricemia in High-Altitude Immigrants

Song Zhen, Anxin Zhang, Jie Luo, Guanghai Xiong, Haibo Peng, Rang Zhou, Yuanfeng Li, Hongqiang Xu, Zhen Li, Wei Zhao, and Haoxiang Zhang. Prevalence of high-altitude polycythemia and hyperuricemia and risk factors for hyperuricemia in high-altitude immigrants. High Alt Med Biol. 24:132-138, 2023. Background: Few studies have investigated the epidemiology of chronic mountain sickness (CMS) in high-altitude immigrants. This study evaluated the prevalence of polycythemia and hyperuricemia (HUA) and risk factors for HUA in high-altitude immigrants. Methods: A cross-sectional study was conducted with 7,070 immigrants 15-45 years of age living on the Tibetan Plateau between January and December 2021. Information from routine physical examinations was obtained from each participant. Binary logistic regression analysis was performed to determine the correlation of several risk factors for HUA. Results: The prevalence of high-altitude polycythemia (HAPC) and HUA was 25.8% (28.7% in males and 9.4% in females) and 54.2% (59.9% in males and 22.5% in females), respectively. The highest prevalence of HAPC in males and females was observed in participants 26-30 and 21-25 years of age, respectively. The highest prevalence of HUA in both males and females was observed in participants 26-30 years of age. Binary logistic regression analysis showed that age, sex, and hemoglobin (Hb) concentration were risk factors for HUA, among which age was a negative factor and male sex and Hb concentration were positive factors. Conclusions: Immigrants are more susceptible to HAPC and HUA. The high prevalence of CMS of immigrants may be associated with Hb concentration, age, and sex.

Relationships of beans intake with chronic kidney disease in rural adults: A large-scale cross-sectional study

Background and aims

Dietary factors play an important role in the development of chronic kidney disease (CKD). However, evidence on the relationship of beans consumption with CKD remains limited and inconclusive, especially in the middle-and low-income populations. The current study aimed to investigate the relationships of beans intake with indicators of kidney injury and CKD prevalence in rural adults.

Methods

A total of 20,733 rural adults from the Henan Rural Cohort Study in 2018–2022 were included. The total beans intake was collected using a validated food frequency questionnaire. Indicators of kidney injury and CKD was determined by the estimated glomerular filtration rate and the urinary albumin to creatinine ratio. Generalized linear regression and logistic regression models were applied to estimate the relationship of beans intake with continuous and dichotomized indicators of renal function, respectively.

Results

Of the 20,733 participants, 2,676 (12.91%) subjects were identified as CKD patients. After adjusting for potential confounders, participants in the higher quartiles of beans intake had a lower prevalence of CKD (odds ratio and 95% confidence interval, OR (95%CI); Q2: 0.968(0.866–1.082); Q3: 0.836(0.744–0.939); Q4: 0.854(0.751–0.970)) and albuminuria (Q2: 0.982(0.875–1.102); Q3: 0.846(0.750–0.954); Q4: 0.852 (0.746–0.973)), compared with the Q1. Per 50 g/day increment in beans intake was significantly associated with a 5 and 4% decreased prevalence of albuminuria and CKD, respectively. These inverse relationships were also significant in the subgroups of men, elder, and high-income participants (p < 0.05).

Conclusion

Dietary beans intake was inversely associated with the prevalence of albuminuria and CKD in rural adults, suggesting that promoting soy food intake might help reduce the occurrence of CKD in rural adults.

Prevalence of chronic kidney disease in a city of Northwestern China: a cross-sectional study

AIM

Chronic kidney disease (CKD) is increasingly recognized as a global health issue. There is a paucity of published data on the prevalence and risk factors of CKD in less-developed regions. This study aims to evaluate and update the prevalence and risk factors of CKD in a city of Northwestern China.

METHODS

Based on a prospective cohort study, a cross-sectional baseline survey was conducted between 2011 and 2013. The data on the epidemiology interview, physical examination, and clinical laboratory test were all collected. In this study, 41,222 participants were selected from 48,001 workers in the baseline after excluding objects with incomplete information. The crude and standardized prevalence of CKD were calculated. An unconditional logistic regression model was used to analyze the risk factors associated with CKD among male and female.

RESULTS

One thousand seven hundred eighty-eight people were diagnosed with CKD, including 1180 males and 608 females. The crude prevalence of CKD was 4.34% (4.78% males and 3.68% females). The standardized prevalence was 4.06% (4.51% males and 3.60% females). The prevalence of CKD increased with age and was higher in males than in females. In multivariable logistic regression, CKD was significantly associated with the increasing age, drinking, never or occasionally exercise, overweight or obesity, being unmarried, diabetes, hyperuricemia, dyslipidemia and hypertension.

CONCLUSION

In this study, the prevalence of CKD was lower than that of the national cross-sectional study. Lifestyle, hypertension, diabetes, hyperuricemia and dyslipidemia were the main risk factors of CKD. The prevalence and risk factors differ between male and female.

Two a posteriori dietary patterns are associated with risks of hyperuricemia among adults in less-developed multiethnic regions in Southwest China

Diet is a major determinant of hyperuricemia, but little is known about the association between diet and hyperuricemia in less-developed multiethnic regions (LMERs). This study aimed to assess the hypothesis that dietary patterns (including 2 a-priori and 3 a posteriori dietary patterns) are associated with hyperuricemia in LMERs. The 2 a priori dietary patterns were the Dietary Approaches to Stop Hypertension (DASH) and the alternative Mediterranean diet (aMED). We derived 3 a posteriori dietary patterns from the China Multi-Ethnic Cohort study by principal component factor analysis. Given that those dietary patterns had high geographic discrimination, they were named the Sichuan Basin (economically developed industrial region), Yunnan-Guizhou Plateau (agricultural region), and Qinghai-Tibet Plateau (nomadic region) dietary pattern, respectively. We performed a logistic regression model to investigate associations between dietary patterns and hyperuricemia with potential confounders identified by the directed acyclic graph. Comparing the highest with the lowest quintiles, the Sichuan Basin dietary pattern was positively associated with hyperuricemia, whereas the Yunnan-Guizhou Plateau dietary pattern showed an inverse association with hyperuricemia. For the Qinghai-Tibet Plateau dietary pattern, DASH, or aMED, our results did not show a significant association with hyperuricemia. The results were robust among stratified analyses and different analyzing strategies. The dietary patterns showed great diversity in Southwest China. Both DASH and aMED, which many studies widely recommended, did not show expected beneficial effects on preventing hyperuricemia. However, the plant-based protein dietary pattern in the Yunnan-Guizhou Plateau showed a beneficial association with the risk of hyperuricemia, which can provide insights for dietary guidance in LMERs.

Chronic kidney disease is more prevalent among women but more men than women are under nephrological care : Analysis from six outpatient clinics in Austria 2019

BACKGROUND

A discrepancy between sex-specific treatment of kidney failure by dialysis (higher in men) and the prevalence of chronic kidney disease in the general population (higher in women) has been reported internationally, but the prevalence by sex has not been described for Austria. Sex disparity among nephrology outpatients has not been studied.

METHODS

We employed two formulae (2009 CKD-EPI suppressing the race factor, and race-free 2021 CKD-EPI) to estimate the sex distribution of CKD in Austrian primary care, based on creatinine measurements recorded in a medical sample of 39,800 patients from general practitioners' offices (1989-2008). Further, we collected information from all clinic appointments scheduled at nephrology departments of 6 Austrian hospitals (Wien, Linz, Wels, St. Pölten, Villach, Innsbruck) during 2019 and calculated visit frequencies by sex.

RESULTS

Using the 2009 CKD-EPI formula, the prevalence of CKD in stages G3-G5 (estimated glomerular filtration rate < 60 mL/min/1.73 m²) was 16.4% among women and 8.5% among men aged > 18 years who had attended general practitioners' offices in Austria between 1989 and 2008 and had at least one creatinine measurement performed. Using the 2021 CKD-EPI formula, the respective CKD prevalence was 12.3% among women and 6.1% among men. In 2019, 45% of all outpatients at 6 participating nephrology departments were women. The median of nephrology clinic visits in 2019 was two (per year) for both sexes.

CONCLUSION

CKD is more prevalent among Austrian women than men. Men are more prevalent in nephrology outpatient services. Research into causes of this sex disparity is urgently needed.

Probability of chronic kidney disease and associated risk factors in Chinese adults: a cross-sectional study of 9 million Chinese adults in the Meinian Onehealth screening survey

Background

Chronic kidney disease (CKD) is an increasing global health problem, but little is known about the age- and sex-specific prevalence of CKD and the associated risk factors in low- and middle-income populations. We examined the age- and sex-specific prevalence of CKD and the associated risk factors in a population-based study of 9 million Chinese adults.

Methods

The study involved a cross-sectional survey of 9 461 631 adults, >18 years of age, who were recruited in 2017 from 31 provinces in the Meinian Onehealth screening survey. All participants had plasma creatinine measured by standard methods and CKD was defined if the estimated glomerular filtration rate (eGFR) was <60 ml/min/1.73 m².

Results

Overall, among 9.5 million adults [mean age 41 years (standard deviation 13.1)], 88 271 (1.26%) had CKD. The prevalence rate of CKD was 1.20%, 0.04% and 0.02% for stage 3, 4 and 5, respectively. After adjustment for the proportion and prevalence of urban and rural areas, the overall prevalence rate of CKD was 1.07%, indicating that ∼14 million Chinese adults have CKD. The prevalence of CKD increased 3-fold for each 10-year increment in age (1.15%, 3.05% and 13.02% at age 50-59, 60-69 and >70 years, respectively) and was 1.8-fold higher in women than men. The prevalence of CKD was higher in the Southwest region {1.68% [95% confidence interval (CI) 1.12-2.24]} but lower in the Northwest region [0.84% (95% CI 0.61-1.07)] than other regions. If proteinuria is also used as a diagnostic criterion, the prevalence rate increased to 2.16%. Stepwise logistic regression analysis demonstrated that body mass index; history of hypertension, cardiovascular disease or diabetes; and levels of systolic blood pressure, triglycerides, fasting glucose and uric acid were independent risk factors for CKD.

Conclusion

CKD is an important public health problem in Chinese adults and this study highlights the need for public health strategies to detect and reduce modifiable risk factors for prevention of CKD.

Effects of high altitude on renal physiology and kidney diseases

The hypobaric and hypoxic conditions of high-altitude areas exert adverse effects on the respiratory, circulatory and nervous systems. The kidneys have an abundant blood supply (20%–25% of cardiac output) and high blood flow; thus, they are susceptible to the effects of hypoxia. However, the effects of acute and chronic exposure to high altitudes on renal physiology and pathology are not fully understood. Moreover, few studies have investigated the impact of high-altitude exposure on patients with chronic kidney disease or acute kidney injury. In this review, we summarized changes in renal physiology and renal pathology due to high-altitude exposure as well as the impact of high-altitude exposure on existing kidney diseases, with the aim of informing the prevention and treatment of kidney diseases at high altitudes.

Where do you live and what do you do? Two questions that might impact your kidney health

In many cases the social determinants of health need to be assessed through their interaction with environmental factors. This review looks at the impact of physical location and occupation of individuals on their kidney health. It examines the effect of living at high altitude on kidney function and the relationship between extreme cold or hot temperatures and the incidence of kidney injury. It reviews as well the many occupations that have been linked to kidney disease in high-income and low-and-middle-income countries. As a conclusion, this overview proposes preventive recommendations that could be individualized based on weather, altitude, socio-economic level of the country and occupation of the individual.

Prevalence, Management, and Associated Factors of Obesity, Hypertension, and Diabetes in Tibetan Population Compared with China Overall

Tibetans’ life expectancy lags behind China’s average. Obesity and noncommunicable diseases (NCDs) contribute to health disparity, but NCD patterns among Tibetans are unknown. To examine the prevalence, management, and associated factors for obesity, hypertension, and diabetes among Tibetans, compared with China’s average, we systematically searched PubMed and China National Knowledge Infrastructure databases for studies between January 2010 and April 2021. Thirty-nine studies were included for systematic review, among thirty-seven that qualified for meta-analysis, with 115,403 participants. Pooled prevalence was 47.9% (95% CI 38.0–57.8) for overweight/obesity among adults (BMI ≥ 24 kg/m²) and 15.4% (13.7–17.2) among children using Chinese criteria, which are lower than the national rates of 51.2% and 19.0%, respectively. The estimate for hypertension (31.4% [27.1–35.7]) exceeded China’s average (27.5%), while diabetes (7.5% [5.2–9.8]) was lower than average (11.9%). Men had a higher prevalence of the three conditions than women. Residents in urban areas, rural areas, and Buddhist institutes had monotonically decreased prevalence in hypertension and diabetes. Awareness, treatment, and control rates for hypertension and diabetes were lower than China’s average. Urban residence and high altitude were consistent risk factors for hypertension. Limited studies investigated factors for diabetes, yet none exist for obesity. Tibetans have high burdens of obesity and hypertension. Representative and longitudinal studies are needed for tailored interventions. There are considerable variations in study design, study sample selection, and data-analysis methods, as well as estimates of reviewed studies.

Prevalence of hypertension and its relationship with altitude in highland areas: a systematic review and meta-analysis

This systematic review and meta-analysis synthesized the pooled prevalence of hypertension at high altitudes and explored its correlation with altitude using studies published in Chinese and English from database inception to February 2021. A systematic literature search was conducted among bibliographic databases (PubMed, Embase, and Web of Science) and three Chinese databases (CNKI, VIP, and Wanfang data) to identify eligible studies. A random-effects model was used to calculate the overall pooled prevalence of hypertension. The I² statistic was used to assess heterogeneity across studies. Random-effects meta-regression was conducted to investigate covariates that may have influenced between-study heterogeneity. The pooled prevalence of hypertension among the general population in high-altitude areas was 33.0% (95% CI: 29.0-38.0%), with high between-study heterogeneity (I² = 99.4%, P < 0.01). Subgroup analyses showed the pooled prevalence of hypertension in Tibetan individuals was significantly higher than that in non-Tibetan individuals living in the Himalayas and Pamir Mountains (41% vs. 18%). A trend toward an increase in the prevalence of hypertension was found with every 100-m increase in elevation (coefficient: 0.012, 95% CI: -0.001 to 0.025, P = 0.069) only in Tibetan individuals. In addition, in these individuals, we found an increase in mean diastolic BP with each 100-m increase in altitude (coefficient: 0.763, 95% CI: 0.122-1.403, P = 0.025). Our meta-analysis suggests that the pooled prevalence of hypertension among the general population in high-altitude areas is 33.0%. Subjects of Tibetan ethnicity were more prone to developing hypertension at high altitudes. However, a very weak relationship between altitude and the prevalence of hypertension was found only in Tibetan individuals.

Nephrologists' Perspectives on Gender Disparities in CKD and Dialysis

Introduction

Globally, there are more women with chronic kidney disease (CKD), yet they comprise only 40% of patients receiving kidney replacement therapy by dialysis. We aimed to describe the perspectives of nephrologists on gender disparities in access to care and outcomes in CKD and dialysis.

Methods

We conducted semistructured interviews with 51 nephrologists (28, 55% women) from 22 countries from October 2019 to April 2020. Transcripts were analyzed thematically.

Results

We identified 6 themes. Related to women were primary commitment to caregiving (with subthemes of coordinating care, taking charge of health management, deprioritizing own health, centrality of family in decision-making); vigilance and self-reliance (diligence and conscientiousness, stoicism and tolerating symptoms, avoiding burden on family, isolation and coping alone); and stereotyping, stigma, and judgment (body image, dismissed as anxiety, shame and embarrassment, weakness and frailty). Related to men was protecting masculinity (safeguarding the provider role, clinging to control, self-regard, and entitled). Decisional power and ownership included men's dominance in decision-making and women's analytical approach in treatment decisions. Inequities compounded by social disadvantage (financial and transport barriers, without social security, limited literacy, entrenched discrimination, vulnerability) were barriers to care for women, particularly in socioeconomically disadvantaged communities.

Conclusion

Nephrologists perceived that women with CKD faced many challenges in accessing care related to social norms and roles of caregiving responsibilities, disempowerment, lack of support, stereotyping by clinicians, and entrenched social and economic disadvantage. Addressing power differences, challenging systemic patriarchy, and managing unconscious bias may help to improve equitable care and outcomes for all people with CKD.

[Prevalence of chronic kidney disease in Antananarivo, Madagascar]

INTRODUCTION

Chronic kidney disease is defined as an inability of the kidney to perform its normal functions and which persists beyond three months. Nowadays, the estimated glomerular filtration rate based on plasmatic creatinine level remains the gold standard to assess renal function. In Madagascar, we miss national data concerning the epidemiology of chronic kidney disease probably due to the complexity of carrying out the serum creatinine assays. The recent availability of creatinometer using a creatinine strip test with capillary creatinine facilitated the determination of the creatinine level in epidemiological study.

PATIENTS AND METHODS

This simple technique allowed us to plan a pilot study in Antananarivo, the capital of Madagascar. The main objective was to assess the prevalence of chronic kidney disease determined from capillary creatinine level. The secondary objective was to determine the factors associated with chronic kidney disease in Madagascar. It is an analytical cross-sectional study over a period of three months. Chronic kidney disease is defined as a decrease of the glomerular filtration rate of capillary creatinine less than 60mL/min/1.73m² and calculated with Chronic Kidney Disease Epidemiology formula (CKD-EPI). The minimum number of studied population has been assessed and settled at 210 people. Cluster sampling was performed for randomization of participants.

RESULTS

At the end of the study, 210 people were randomized for screening. The average age was 40 years old with 14.9 as standard deviation. The sex ratio (male/female) was 1.76. The prevalence of chronic kidney disease was 13.8% with extreme values of 9,1 and 18.5. With chronic kidney disease, high blood pressure (hypertension) and diabetes were found respectively in 41.3 and 17.2%. Chronic kidney disease affected mainly in 72.4% of population aged 25 to 54 years old.

CONCLUSION

This is the first study in Africa to screen chronic kidney disease using a creatinine strip test. This prevalence is relatively different compared to other African countries. The limits of the study are the absence of a subsequent control and/or double control of the creatinine, which definitively confirms the chronicity of kidney disease, the absence evaluation of the urinary sediments to determine proteinuria. Nevertheless, the results of our study can be used as data awaiting the results of a multicenter studies. To determine the national prevalence of chronic kidney disease, screening in the six provinces is currently in progress.

Prevalence and Associated Factors of Kidney Dysfunction in Patients with Hypertension and/or Diabetes Mellitus from a Primary Care Population in Northwest China

Purpose

The burden of kidney dysfunction (KD) is rapidly increasing in developing countries due to an ongoing epidemic of hypertension and diabetes. We aimed to evaluate the prevalence and associated factors of KD among population with hypertension and/or diabetes from primary care setting.

Methods

This study was part of a cross-sectional study conducted in Northwest China, which aimed to investigate the epidemiological status of hypertension and other chronic noninfectious diseases. Subjects aged ≥18 years old with hypertension and/or diabetes were included in this study. KD was defined as estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73m². Least absolute shrinkage and selection operator and multivariable logistic regression were used to identify factors associated with KD. Sensitivity analysis was performed by comparing the results of different estimated equations for GFR.

Results

A total of 8899 participants with hypertension and/or diabetes were included. Prevalence of KD was 8.69% (n=144) among patients with both hypertension and DM, 3.36% (n=198) among patients with only hypertension, and 5.22% (n=70) among patients with only diabetes. Women showed higher prevalent KD than men. Modifiable factors independently associated with KD among patients with hypertension and/or diabetes included physical activity, duration of hypertension or DM, anemia, fasting plasma glucose and triglyceride. Results of different estimated equations showed similar trends of difference in the prevalence of KD among groups.

Conclusion

KD is common in patients with hypertension and/or DM in Northwest China. More attention should be paid to high-risk patients, especially to those with co-existence of hypertension and DM. Control of blood glucose and triglyceride may further improve KD management in this patient population.

Global REACH 2018: Volume regulation in high-altitude Andeans with and without chronic mountain sickness

The high-altitude maladaptation syndrome known as chronic mountain sickness (CMS) is characterized by polycythemia and is associated with proteinuria despite unaltered glomerular filtration rate. However, it remains unclear if indigenous highlanders with CMS have altered volume regulatory hormones. We assessed N-terminal pro-B-type natriuretic peptide (NT pro-BNP), plasma aldosterone concentration, plasma renin activity, kidney function (urinary microalbumin, glomerular filtration rate), blood volume, and estimated pulmonary artery systolic pressure (ePASP), in Andean males without (n=14; age=39±11) and with (n=10; age=40±12) CMS at 4330 meters (Cerro de Pasco, Peru). Plasma renin activity (non-CMS: 15.8±7.9 vs. CMS: 8.7±5.4 ng/ml; p=0.025) and plasma aldosterone concentration (non-CMS: 77.5±35.5 vs. CMS: 54.2±28.9 pg/ml; p=0.018) were lower in highlanders with CMS compared to non-CMS, while NT pro-BNP was not different between groups (non-CMS: 1394.9±214.3 vs. CMS: 1451.1±327.8 pg/ml; p=0.15). Highlanders had similar total blood volume (non-CMS: 90±15 vs. CMS: 103±18 ml • kg^-1; p=0.071), but Andeans with CMS had greater total red blood cell volume (non-CMS: 46±10 vs. CMS 66±14 ml • kg^-1; p<0.01) and smaller plasma volume (non-CMS 43±7 vs. CMS 35±5 ml • kg^-1; p=0.03) compared to non-CMS. There were no differences in ePASP between groups (non-CMS 32±9 vs. CMS 31±8 mmHg; p=0.6). A negative correlation was found between plasma renin activity and glomerular filtration rate in both groups (group: r=-0.66; p<0.01; non-CMS: r=-0.60; p=0.022; CMS: r=-0.63; p=0.049). A smaller plasma volume in Andeans with CMS may indicate an additional CMS maladaptation to high-altitude, causing potentially greater polycythemia and clinical symptoms.

Are the tribal highlanders protected from hypertension? A meta-analysis on prevalence of hypertension among high altitude tribal population of India

Background

The so-called protected tribal population are also facing burden of noncommunicable diseases. The high altitude tribes are thought to be genetically and environmentally protected from hypertension (HTN) like diseases.

Objective

The objective is to estimate the prevalence of HTN among tribes residing at high altitudes (>6000 feet above sea level) of India.

Methods

The meta-analysis was undertaken during March to August 2018. National Library of Medicine's PubMed database, and Google scholar were comprehensively searched including search terms such as "blood pressure, hypertension and prevalence" combined with "tribal, tribes, high altitude, India." Articles on the prevalence of HTN were searched first and then were segregated on the basis of high altitude (>6000 ft).

Results

Initially, 69 references and a total of 16 abstracts were screened. After applying the inclusion and exclusion criteria on 16, eight studies were included. Meta-analysis of the prevalence of selected studies resulted in a pooled estimate mean prevalence of HTN among tribal population to be 11.43% (95% confidence interval: 6.72%-17.21%).

Conclusion

The role of epidemiological transition needs to be read in the context of social anthropology to identify factors preventing HTN among high altitude tribes.

Impact of twice- or three-times-weekly maintenance hemodialysis on patient outcomes: A multicenter randomized trial

AIM

Maintenance hemodialysis (MHD) frequency is associated with survival and complication rates. Achieving the optimal balance between healthcare, quality of life (QOL), and medical costs is challenging. We compared complications, inflammatory status, nutritional status, and QOL between patients with different MHD frequencies.

MATERIAL AND METHODS

This was a multicenter randomized trial of patients treated between May 2011 and August 2017 at 3 tertiary hospitals in Wenzhou. Patients were grouped according to their treatment schedule over 1 year: twice-weekly or 3-times-weekly. Complications, biochemistry parameters, and QOL (KDQOL-SFTM 1.3 scale) were assessed.

RESULTS

One hundred forty patients were included aged 29 to 68 years (mean age, 50.9 ± 4.3 years). There were no significant differences in infection, heart failure, or cerebral hemorrhage complications between the 2 groups (P = .664). Pre-dialysis hemoglobin, high-sensitivity C-reactive protein, serum albumin, total cholesterol, triglyceride, calcium, phosphate, parathyroid hormone, and ejection fraction were similar in both groups (P > .05). After 1 year of MHD, both groups exhibited significant improvements in these parameters (all P < .05) with no significant differences between groups. Serum creatinine, blood urea nitrogen (BUN), and weekly standard hemodialysis treatment adequacy did not improve after treatment (all P > .05), although a difference in BUN was observed between the 2 groups (P < .001). QOL was superior in the twice-weekly group than in the 3-times-weekly group (all P < .05), except for social support, which was slightly better in the 3-times-weekly group than in the twice-weekly group.

CONCLUSIONS

Twice- and 3-times-weekly MHD resulted in comparable inflammatory and nutritional clinical outcomes and adverse events. QOL was better for the twice-weekly schedule. Even for patients with economic constraints, twice- or 3-times-weekly MHD should be selected with caution after consideration of BUN levels at baseline.

Metabolic syndrome and its relation to dietary patterns among a selected urbanised and semi-urbanised Tibetan population in transition from nomadic to settled living environment

OBJECTIVE

To explore the scope of metabolic syndrome (MetS) and its relationship to the major dietary patterns among an urbanised and semi-urbanised Tibetan population in transition from nomadic to settled settings.

DESIGN

Cross-sectional.

SETTING

Community-based.

PARTICIPANTS

Urbanised and semi-urbanised Tibetan adults (n 920, aged 18-90 years), who have moved from nomadic to settled living environments, answered questionnaires on food consumption frequency and lifestyle characteristics through structured face-to-face interviews and completed anthropometric measurement and metabolic biomarker tests.

RESULTS

MetS prevalence was 30·1 % in males and 32·1 % in females. Low HDL-cholesterol and central obesity were the leading metabolic abnormalities (86·3 and 55·8 %, respectively). Three major dietary patterns - urban, western and pastoral - were identified. Beef/mutton was an important food group for all three identified dietary patterns. In addition, the urban dietary pattern was characterised by frequent consumption of vegetables, tubers/roots and refined carbohydrates; the western pattern was characterised by sweetened drinks, snacks and desserts; and the pastoral pattern featured tsamba (roasted Tibetan barley), Tibetan cheese, butter tea/milk tea and whole-fat dairy foods. Individuals in the highest quintile of urban dietary pattern scores were found to be at a higher risk of developing MetS (OR 2·43, 95 % CI 1·41, 4·18) and central obesity (OR 1·91, 95 % CI 1·16, 3·14) after controlling for potential confounders.

CONCLUSIONS

MetS was common among urbanised and semi-urbanised Tibetan adult population in transition. The urban dietary pattern, in particular, was a risk factor for MetS. To prevent MetS, nutrition interventions need to be tailored to address the variety of local diet patterns to promote healthy eating.

Prevalence and risk factors of chronic kidney disease and diabetic kidney disease in a central Chinese urban population: a cross-sectional survey

Background

This study was conducted to evaluate and update the current prevalence of and risk factors for chronic kidney disease (CKD) and diabetic kidney disease (DKD) in a central Chinese urban population.

Methods

From December 2017 to June 2018, a total of 5231 subjects were randomly enrolled from 3 communities in 3 districts of Zhengzhou. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min.1.73m² or urinary albumin to creatinine ratio ≥ 30 mg/g (albuminuria). Diabetic subjects with systolic blood pressure > 140 mmHg, albuminuria or an eGFR less than 60 mL/min/1.73 m² were classified as having DKD. Participants completed a questionnaire assessing lifestyle and relevant medical history, and blood and urine specimens were taken. Serum creatinine, uric acid, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein and urinary albumin were assessed. The age- and sex-adjusted prevalences of CKD and DKD were calculated, and risk factors associated with the presence of reduced eGFR, albuminuria, DKD, severity of albuminuria and progression of reduced renal function were analyzed by binary and ordinal logistic regression.

Results

The overall adjusted prevalence of CKD was 16.8% (15.8–17.8%) and that of DKD was 3.5% (3.0–4.0%). Decreased renal function was detected in 132 participants (2.9, 95% confidence interval [CI]: 2.5–3.2%), whereas albuminuria was found in 858 participants (14.9, 95% CI: 13.9–15.9%). In all participants with diabetes, the prevalence of reduced eGFR was 6.3% (95% CI = 3.9–8.6%) and that of albuminuria was 45.3% (95% CI = 40.4–50.1%). The overall prevalence of CKD in participants with diabetes was 48.0% (95% CI = 43.1–52.9%). The results of the binary and ordinal logistic regression indicated that the factors independently associated with a higher risk of reduced eGFR and albuminuria were older age, sex, smoking, alcohol consumption, overweight, obesity, diabetes, hypertension, dyslipidemia and hyperuricemia.

Conclusions

Our study shows the current prevalence of CKD and DKD in residents of Central China. The high prevalence suggests an urgent need to implement interventions to relieve the high burden of CKD and DKD in China.

Prevalence and Associated Risk Factors of Chronic Kidney Disease in an Elderly Population from Eastern China

Chronic kidney disease (CKD) is a global major public health problem. Almost all of previous studies evaluating the prevalence of CKD focused on adults, while studies among the elderly were relatively rare, especially in China. The aim of this study was to investigate the prevalence and associated risk factors of CKD among the elderly in Qingdao, China. This was a cross-sectional study with 38,038 inhabitants (aged 60-109) randomly recruited in Qingdao, China. All participants were required to complete a questionnaire for their demographic characteristics. Blood and urine samples of participants were collected, and the albumin and creatinine levels were measured for albuminuria and estimated glomerular filtration rate (eGFR) assessment. The associations between risk factors and indicators of kidney damage were analyzed by logistic regression. A total of 34,588 inhabitants completed the survey. The overall prevalence of CKD was 11.41% (95% confidence interval (CI): 11.07-11.74%) in the elders from Qingdao in 2016. The prevalence of albuminuria and low eGFR (<60 mL/min per 1·73 m²) were 8.47% (95% CI: 8.17-8.76%) and 3.98% (95% CI: 3.78-4.19%), respectively. Older age, hypertension, diabetes, anemia, hyperuricemia, hyperhomocysteinemia, hypertriglyceridemia, obesity, and LDL-C ≥ 4.1 mmol/L were independently associated with the presence of CKD. In conclusion, common chronic non-communicable diseases, including hypertension, diabetes, obesity, hyperhomocysteinemia, hyperuricemia, and hypertriglyceridemia, were associated with greater prevalence of CKD.

Blood pressure level increase with altitude in three argentinean indigenous communities

Objective

To compare blood pressure (BP) levels in three groups of Argentinean Indigenous schoolchildren from similar ethnic backgrounds but living at three different altitudes.

Methods

A cross-sectional study compared 185 (83 females) children aged 5–14 years from San Antonio de los Cobres (SAC), 3750 m above sea level; 46 (23 females) from Cobres, 3450 m; and 167 (83 females) from Chicoana (CH), 1400 m. Anthropometric and BP measurements were performed.

Results

The prevalence of overweight/obesity was lower in SAC (6.5% [12]) and Cobres (4.3% [2]) than in CH (24% [24]) (BMI > 85 percentile per CDC norms). Systolic BP increased significantly with altitude: (SAC 86 mm Hg, Cobres 77 mm Hg, and CH 69 mm Hg). Similar results were obtained with diastolic BP (SAC 57 mm Hg, Cobres 51 mm Hg, and CH 47 mm Hg) and with median arterial pressure (MAP) (SAC 67 mm Hg, Cobres 60 mm Hg, and CH 55 mm Hg). Multiple linear regression analyses showed that altitude was significantly and independently associated with children's systolic BP (beta 10.56; R² = 0.40), diastolic BP (beta 6.27; R² = 0.25) and MAP (beta 7.69; R² = 0.32); adjusted for age, sex, and BMI.

Conclusions

We found that as altitude increased, BP levels increased significantly in indigenous children from similar backgrounds living permanently at different altitudes.

Prevalence of kidney damage in Chinese elderly: a large-scale population-based study

BACKGROUND

In China, both population aging and kidney damage has become emerging public health challenges. Despite the number of elders is huge, data on kidney damage in this population are scarce. The present study aimed to describe the prevalence of kidney damage among older adults in Wuhan, China.

METHODS

To describe the prevalence of kidney damage among Chinese elderly, the health screening data of 350,881 adults older than 65 years in Wuhan, China were collected and analyzed. Kidney damage was defined as eGFR less than 60 mL/min per 1·73 m2 or the presence of proteinuria. Decreased renal function was defined as an eGFR < 60 mL/min/1.73 m2. Proteinuria was defined as urine protein ≥1+ and without urine WBC or nitrite positive. The associated risk factors of eGFR decline and kidney damage were analyzed by multivariate logistic regression.

RESULTS

The age-standardized prevalence of kidney damage, decreased renal function and proteinuria was 17.2, 13.5 and 5.3%. Among the patients, up to 74.4% was stage 3. The prevalence of kidney damage and eGFR decline were higher in suburbs than in urban (18.3% vs 16.0 and 14.6% vs 12.4%). Factors independently associated with kidney damage were age, female, BMI, abdominal circumference, hypertension, diabetes, stroke and coronary heart disease.

CONCLUSIONS

Kidney damage has become an important public health problem in Chinese elderly. More attention should be paid to elderly lived in suburbs or rural area in our further work.

Intrarenal microRNA signature related to the fibrosis process in chronic kidney disease: identification and functional validation of key miRNAs

BACKGROUND

Though the roles of microRNAs (miRNAs) in renal diseases have been extensively investigated, a thorough screening and comparison of miRNAs among different types of chronic kidney disease (CKD) has never been performed.

METHODS

The intrarenal miRNAs were profiled from fresh kidney tissues of patients with biopsy-proven minimal change disease (MCD), focal segmental glomerular sclerosis (FSGS) and diabetic nephropathy (DN) by using microarray. Commonly dysregulated miRNAs were validated by real-time PCR using paraffin-embedded renal tissues from all three types of CKD patients as well as mouse unilateral ureteral obstruction (UUO) model. Two novel miRNAs were selected and annotations of their target genes were performed using GO and KEGG pathway enrichment analysis. Biological functions of three two candidate miRNAs were explored in TGF-β1-induced cell model using human kidney proximal tubular cells (HK-2).

RESULTS

The kidney biopsy samples of three disease types represent different levels of damage and fibrosis, which were the mildest in MCD, moderate in FSGS, and the most severe in DN. 116 miRNAs were identified to be commonly dysregulated, including 40 up-regulated and 76 down-regulated in CKD tissues as compared with healthy donor kidney biopsy tissues. Two novel miRNAs, hsa-miR-3607-3p and hsa-miR-4709-3p, were verified as consistently differentially expressed among all three types of patient samples as well as in mouse model. In vitro, hsa-miR-3607-3p was repressed while hsa-miR-4709-3p was induced by TGF-β1 treatment. Inhibition of hsa-miR-3607-3p or overexpression of hsa-miR-4709-3p promoted TGF-β1-induced migration and F-actin assembling in HK-2 cells, which are characteristics of epithelial-mesenchymal transition (EMT). Further study identified that ITGB8 and CALM3 were the bona fide target genes of hsa-miR-3607-3p and hsa-miR-4709-3p respectively.

CONCLUSIONS

The present identify a unique miRNAs profile that probably relates to the common fibrosis process of CKD. Results of our study suggest that hsa-miR-3607-3p and hsa-miR-4709-3p may represent as promising therapeutic targets against kidney fibrosis.

Prevalence and risk factors of chronic kidney disease and diabetic kidney disease in Chinese rural residents: a cross-sectional survey

We conducted a cross-sectional survey including 23869 participants and aimed to measure the prevalences of and risk factors for chronic kidney disease (CKD) and diabetic kidney disease (DKD) in a Chinese rural population. CKD and DKD status was defined according to the combination of estimated glomerular filtration rate (eGFR) and presence of albuminuria Participant completed a questionnaire involving life-style and relevant medical history, and the blood and urinary specimen were taken. The age- and gender- adjusted prevalences of CKD and DKD were calculated and risk factors associated with the presence of CKD and DKD were analyzed by logistic regression. The overall prevalence of CKD was 16.4% (15.9–16.8%) and of DKD was 2.9% (2.7–3.1%). In participants with diabetes, the overall prevalence of CKD was 35.5% (95% CI = 33.7–37.3%). Factors independently associated with renal damage were age, gender, education, personal income, alcohol consumption, overweight, obesity, diabetes, hypertension and dyslipidemia. Our study shows current prevalences of CKD and DKD in Chinese rural residents. Further researches could identify potential factors explaining the observed differences and implement the interventions to relieve the high burden of CKD and DKD in rural population.

Glomerular Hematuria: Cause or Consequence of Renal Inflammation?

Glomerular hematuria is a cardinal symptom of renal disease. Glomerular hematuria may be classified as microhematuria or macrohematuria according to the number of red blood cells in urine. Recent evidence suggests a pathological role of persistent glomerular microhematuria in the progression of renal disease. Moreover, gross hematuria, or macrohematuria, promotes acute kidney injury (AKI), with subsequent impairment of renal function in a high proportion of patients. In this pathological context, hemoglobin, heme, or iron released from red blood cells in the urinary space may cause direct tubular cell injury, oxidative stress, pro-inflammatory cytokine production, and further monocyte/macrophage recruitment. The aim of this manuscript is to review the role of glomerular hematuria in kidney injury, the role of inflammation as cause and consequence of glomerular hematuria, and to discuss novel therapies to combat hematuria.

Prevalence and risk factors associated with hyperuricemia among working population at high altitudes: a cross-sectional study in Western China

Chronic exposure to high altitude may lead to hyperuricemia. We investigated the prevalence of hyperuricemia and its risk factors among employees in high-altitude areas. A cross-sectional survey with cluster sampling was performed at 23 worksites on the Qinghai-Tibet Plateau. Subjects were evaluated by using questionnaires, anthropometric and laboratory measurements, and abdominal ultrasound. A multilevel logistic regression model and restricted cubic spline were used to explore the associated factors of hyperuricemia. Of the 4198 employees included in the study, the age-standardized prevalence of hyperuricemia was 28.1% (95% confidence interval (CI) 26.7-29.5), with 31.9% (95%CI 30.2-33.6) in men and 17.9% (95%CI 15.7-20.1) in women. Hypertension, hyperlipidemia, and a meat-food pattern were positively associated with hyperuricemia in both sexes, while diabetes, shift work, body mass index, non-alcoholic fatty liver disease, and low intake of fruits and vegetables were significantly associated with hyperuricemia only in men. Furthermore, a nonlinear dose-response association between the number of cardiovascular risk factors (CRFs) and hyperuricemia was observed. Compared with those having 0 CRFs, the full-adjusted odds ratios (ORs) and 95%CIs for 1, 2, and ≥ 3 CRFs were 1.76 (95%CI 1.25-2.47), 2.54 (95%CI 1.81-3.55), and 3.05 (95%CI 2.16-4.31) in men, respectively, and 2.13 (95%CI 1.43-3.17), 2.78 (95%CI 1.71-4.53), and 3.13 (95%CI 1.50-6.55) in women, respectively. Hyperuricemia is common in employees at high-altitude areas. However, working at higher altitudes does not mean necessarily higher risk of hyperuricemia, as dietary factors and clustered CRFs are more significant. Thus, workplace-based lifestyle modifications should be promoted.

Effect of Oral Vitamin C Supplementation on High-Altitude Hyperuricemia in Young Men Initially Migrating to High Altitude: A Pilot Study

OBJECTIVE

Clinical studies have shown that oral vitamin C supplementation can reduce serum uric acid levels in multiple populations and may also improve acute mountain sickness. However, it is unclear whether this protocol can improve high-altitude hyperuricemia. Therefore, we aimed to evaluate the role of vitamin C supplementation on high-altitude hyperuricemia.

METHODS

A preliminary prospective control study was performed in 2015. Young male army recruits (n = 66), who had recently arrived on the Tibetan Plateau for the first time, were recruited for study I. Subjects were assigned to either the vitamin C group, who took an oral daily dose of 500 mg vitamin C for 1 month, or the blank control group, who had no intervention. The levels of serum uric acid, serum creatinine, and blood urea nitrogen were monitored at baseline and at the end of 1 month. In a second study II in 2016 (n = 120), the effect of 500 mg/d vitamin C on high-altitude hyperuricemia was compared with 75 IU/d of vitamin E.

RESULTS

In study I, the level of serum uric acid at 1 month was significantly higher than at baseline (436.1 ± 79.3 μmol/L vs. 358.0 ± 79.8 μmol/L, p < 0.001) and the prevalence of hyperuricemia was also significantly higher (63.6% [95% confidence interval, CI: 52.0%-75.2%] vs. 19.7% [95% CI: 10.1%-29.3%], p < 0.001). Both the level of serum uric acid (411.5 ± 74.2 μmol/L vs. 460.8 ± 54.8 μmol/L, p = 0.003) and the prevalence of hyperuricemia (48.5% [95% CI: 31.4%-65.6%] vs. 78.8% [95% CI: 64.9%-92.7%], p = 0.020) were significantly lower in the vitamin C group than in the blank control group. In study II, the levels of serum uric acid and the frequency of hyperuricemia also increased over 1 month and were similar in the vitamin C and the vitamin E groups at both baseline and 1 month (p > 0.05). The change in serum uric acid was positively correlated with both the changes in serum creatinine (r = 0.599, p < 0.001) and blood urea nitrogen (r = 0.207, p = 0.005).

CONCLUSIONS

These findings indicate that healthy young men develop an increase in serum uric acid within a month of moving from low to high altitude. Oral vitamin C supplementation can safely reduce this increase at a low cost.

Hypoxia-induced hyperpermeability of rat glomerular endothelial cells involves HIF-2α mediated changes in the expression of occludin and ZO-1

This study aimed to investigate the role of hypoxia-inducible factor-2α (HIF-2α) in the expression of tight junction proteins and permeability alterations in rat glomerular endothelial cells (rGENCs) under hypoxia conditions. The expression level of HIF-2α and tight junction proteins (occludin and ZO-1) in rGENCs were examined following 5% oxygen density exposure at different treatment times. HIF-2α lentivirus transfection was used to knockdown HIF-2α expression. Cells were divided into four groups: 1) control group (rGENCs were cultured under normal oxygen conditions), 2) hypoxia group (rGENCs were cultured under hypoxic conditions), 3) negative control group (rGENCs were infected with HIF-2α lentivirus negative control vectors and cultured under hypoxic conditions), and 4) Len group (rGENCs were transfected with HIF-2α lentivirus and cultured under hypoxic conditions). The hypoxia, negative control, and Len groups were kept in a hypoxic chamber (5% O2, 5% CO2, and 90% N2) for 24 h and the total content of occludin and ZO-1, and the permeability of rGENCs were assessed. With increasing hypoxia time, the expression of HIF-2α gradually increased, while the expression of occludin decreased, with a significant difference between groups. ZO-1 expression gradually decreased under hypoxia conditions, but the difference between the 24 and 48 h groups was not significant. The permeability of cells increased following 24-h exposure to hypoxia compared to the control group (P<0.01). The knockdown of HIF-2α expression significantly increased occludin and ZO-1 content compared with hypoxia and negative control groups (P<0.01), while permeability was reduced (P<0.01). Hypoxia increased HIF-2α content, inducing permeability of rGENCs through the reduced expression of occludin and ZO-1.

Prevalence and risk factors associated with chronic kidney disease in adults living in 3 different altitude regions in the Tibetan Plateau

BACKGROUND

Living at high altitude may have undesirable effects on the kidney. We explored the chronic kidney disease (CKD) prevalence and risk factors among the residents living at different altitude in Tibetan Plateau.

METHODS

A cross-sectional study was carried out in 2014 to 2016 in Linzhi (2900 m altitude), Lhasa (3650 m) and Anduo (4700 m). Information on the cardiovascular risk factors was collected and blood and urine samples were measured.

RESULTS

The data of 1707 subjects aged ≥35 y were analyzed. The age-standardized prevalence of CKD in Linzhi, Lhasa and Anduo was 27.7% (95% CI: 22.1-33.3%), 18.3% (12.7-24.0%) and 30.4% (23.5-37.3%) in men and 37.7% (31.8-43.6%), 29.5% (24.6-34.4%) and 36.7% (29.0-44.4%) in women, respectively. Multivariable logistic regression showed that age, female gender, systolic blood pressure, fasting serum glucose, with primary school education or lower were associated with higher risk of CKD and living in Lhasa was associated with lower risk of CKD.

CONCLUSION

A higher prevalence of CKD was found in the residents living in the Tibetan Plateau. However, for the highlanders living at higher altitude does not mean higher risk. The CKD risk factors found in this study are similar to those in other studies.

Sex and gender disparities in the epidemiology and outcomes of chronic kidney disease

Improved understanding of sex and gender-specific differences in the aetiology, mechanisms and epidemiology of chronic kidney disease (CKD) could help nephrologists better address the needs of their patients. Population-based studies indicate that CKD epidemiology differs by sex, affecting more women than men, especially with regard to stage G3 CKD. The effects of longer life expectancy on the natural decline of glomerular filtration rate (GFR) with age, as well as potential overdiagnosis of CKD through the inappropriate use of GFR equations, might be in part responsible for the greater prevalence of CKD in women. Somewhat paradoxically, there seems to be a preponderance of men among patients starting renal replacement therapy (RRT); the protective effects of oestrogens in women and/or the damaging effects of testosterone, together with unhealthier lifestyles, might cause kidney function to decline faster in men than in women. Additionally, elderly women seem to be more inclined to choose conservative care instead of RRT. Dissimilarities between the sexes are also apparent in the outcomes of CKD. In patients with predialysis CKD, mortality is higher in men than women; however, this difference disappears for patients on RRT. Although access to living donor kidneys among men and women seems equal, women have reduced access to deceased donor transplantation. Lastly, health-related quality of life while on RRT is poorer in women than men, and women report a higher burden of symptoms. These findings provide insights into differences in the underlying pathophysiology of disease as well as societal factors that can be addressed to reduce disparities in access to care and outcomes for patients with CKD.

Sex and gender disparities in the epidemiology and outcomes of chronic kidney disease

Improved understanding of sex and gender-specific differences in the aetiology, mechanisms and epidemiology of chronic kidney disease (CKD) could help nephrologists better address the needs of their patients. Population-based studies indicate that CKD epidemiology differs by sex, affecting more women than men, especially with regard to stage G3 CKD. The effects of longer life expectancy on the natural decline of glomerular filtration rate (GFR) with age, as well as potential overdiagnosis of CKD through the inappropriate use of GFR equations, might be in part responsible for the greater prevalence of CKD in women. Somewhat paradoxically, there seems to be a preponderance of men among patients starting renal replacement therapy (RRT); the protective effects of oestrogens in women and/or the damaging effects of testosterone, together with unhealthier lifestyles, might cause kidney function to decline faster in men than in women. Additionally, elderly women seem to be more inclined to choose conservative care instead of RRT. Dissimilarities between the sexes are also apparent in the outcomes of CKD. In patients with predialysis CKD, mortality is higher in men than women; however, this difference disappears for patients on RRT. Although access to living donor kidneys among men and women seems equal, women have reduced access to deceased donor transplantation. Lastly, health-related quality of life while on RRT is poorer in women than men, and women report a higher burden of symptoms. These findings provide insights into differences in the underlying pathophysiology of disease as well as societal factors that can be addressed to reduce disparities in access to care and outcomes for patients with CKD.

Higher prevalence of unrecognized kidney disease at high altitude

BACKGROUND

High altitude renal syndrome has been described in populations with excessive erythrocytosis. We evaluated whether high altitude (HA) dwellers might be at increased risk for kidney disease.

METHODS

We performed a cross-sectional study to investigate differences in prevalence of kidney function and metabolic syndrome in healthy subjects living at HA vs. sea level (SL) without any known history of hypertension, diabetes or chronic kidney disease.

RESULTS

We examined 293 subjects, aged 40 to 60 years: 125 SL (154 m) and 168 HA (3640 m) dwellers. HA dwellers had higher serum creatinine, lower estimated glomerular function rate (eGFR) (69.5 ± 15.2 vs. 102.1 ± 17.8 ml/min/1.73 m², p < 0.0001), more proteinuria and higher hemoglobin concentrations compared to SL subjects. HA subjects had a lower prevalence of metabolic syndrome. Hemoglobin concentrations correlated inversely with eGFR in female (p = 0.001) and male (p = 0.03) HA dwellers. Using logistic regression analysis to compare subjects with eGFR < 90 vs. > 90 ml/min/1.73 m², a lower eGFR was associated with female gender (odds ratio adjusted: 5.65 [95% confidence interval: 2.43-13.13]; p = 0.001), high altitude (14.78 [6.46-33.79]; p = 0.001), hemoglobin (1.68 [1.16-2.43]; p = 0.001) and uric acid (1.93 [1.36-2.72]; p = 0.001).

CONCLUSIONS

Dwellers at high altitude who are considered healthy have worse kidney function, a higher prevalence of proteinuria and a lower prevalence of metabolic syndrome compared to people living at SL.

Prevalence of chronic kidney disease in patients with chronic hepatitis B: A cross-sectional survey

Renal safety is a major concern during long-term antiviral treatment for chronic hepatitis B (CHB). This study aimed to investigate the prevalence of chronic kidney disease (CKD) in patients with CHB that had been treated with antiviral therapy. This was a single-centre, cross-sectional study in a real-life cohort in which all patients received antiviral treatment. Serum creatinine-based equations from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) were used to estimate the glomerular filtration rate (GFR). CKD was defined as an eGFR <60 mL/min/1.73 m² or a urinary albumin to creatinine ratio ≥ 3 mg/mmol (defined as albuminuria). Univariate and multivariate analyses were conducted to determine the risk factors of CKD. A total of 1985 patients were included in the analysis from February 2015 to December 2015. The mean age and median duration of antiviral treatment was 42.20 years and 17.05 months, respectively. The overall prevalence of CKD was 7.9% (157/1985), with 44 patients experiencing decreased renal function (eGFR less than 60 mL/min/1.73 m²) and 129 patients with albuminuria. Patients with cirrhosis had a higher prevalence of a decreased GFR (4.3% vs 1.6%, P<.001) and albuminuria (11.1% vs 5.2%, P<.001) than those without cirrhosis. In the multivariate analysis, hypertension (Odds Ratio [OR] 4.564, P<.001), diabetes mellitus (OR 2.688, P<.001) and cirrhosis (OR 1.918, P<.001) were independent factors associated with the presence of CKD. CKD was a clinically significant comorbidity in patients with CHB. Special attention should be paid to cirrhotic patients and patients with the metabolic syndrome.

Chronic Hypobaric Hypoxia Modulates Primary Cilia Differently in Adult and Fetal Ovine Kidneys

Hypoxic environments at high altitude have significant effects on kidney injury. Following injury, renal primary cilia display length alterations. Primary cilia are mechanosensory organelles that regulate tubular architecture. The effect of hypoxia on cilia length is still controversial in cultured cells, and no corresponding in vivo study exists. Using fetal and adult sheep, we here study the effect of chronic hypobaric hypoxia on the renal injury, intracellular calcium signaling and the relationship between cilia length and cilia function. Our results show that although long-term hypoxia induces renal fibrosis in both fetal and adult kidneys, fetal kidneys are more susceptible to hypoxia-induced renal injury. Unlike hypoxic adult kidneys, hypoxic fetal kidneys are characterized by interstitial edema, tubular disparition and atrophy. We also noted that there is an increase in the cilia length as well as an increase in the cilia function in the hypoxic fetal proximal and distal collecting epithelia. Hypoxia, however, has no significant effect on primary cilia in the adult kidneys. Increased cilia length is also associated with greater flow-induced intracellular calcium signaling in renal epithelial cells from hypoxic fetuses. Our studies suggest that while hypoxia causes renal fibrosis in both adult and fetal kidneys, hypoxia-induced alteration in cilia length and function are specific to more severe renal injuries in fetal hypoxic kidneys.

Endothelial Epas1 Deficiency Is Sufficient To Promote Parietal Epithelial Cell Activation and FSGS in Experimental Hypertension

FSGS, the most common primary glomerular disorder causing ESRD, is a complex disease that is only partially understood. Progressive sclerosis is a hallmark of FSGS, and genetic tracing studies have shown that parietal epithelial cells participate in the formation of sclerotic lesions. The loss of podocytes triggers a focal activation of parietal epithelial cells, which subsequently form cellular adhesions with the capillary tuft. However, in the absence of intrinsic podocyte alterations, the origin of the pathogenic signal that triggers parietal epithelial cell recruitment remains elusive. In this study, investigation of the role of the endothelial PAS domain-containing protein 1 (EPAS1), a regulatory α subunit of the hypoxia-inducible factor complex, during angiotensin II-induced hypertensive nephropathy provided novel insights into FSGS pathogenesis in the absence of a primary podocyte abnormality. We infused angiotensin II into endothelial-selective Epas1 knockout mice and their littermate controls. Although the groups presented with identical high BP, endothelial-specific Epas1 gene deletion accentuated albuminuria with severe podocyte lesions and recruitment of pathogenic parietal glomerular epithelial cells. These lesions and dysfunction of the glomerular filtration barrier were associated with FSGS in endothelial Epas1-deficient mice only. These results indicate that endothelial EPAS1 has a global protective role during glomerular hypertensive injuries without influencing the hypertensive effect of angiotensin II. Furthermore, these findings provide proof of principle that endothelial-derived signaling can trigger FSGS and illustrate the potential importance of the EPAS1 endothelial transcription factor in secondary FSGS.

[Chronic kidney disease: associated factors, etiologies, clinical and biological parameters at Lubumbashi city in Democratic Republic of Congo]

INTRODUCTION

Chronic kidney disease is fast becoming a worldwide public health problem due to the increase of hypertension and diabetes mellitus, its main risk factors. In countries like DRC where majority of population are in the low income bracket, very few studies about this disease, usually diagnosed at a very advanced stage have been conducted. As a result of such, cases are not always properly taken care of and managed.

METHODS

We opted for a descriptive cross-sectional study and it was conducted during the period from July 2014 to July 2015 at CMDC dialysis service. Were included all patients with glomerular filtration rate lower than 60ml / min / 1,73 m2 or high level of creatinine longer than three months during the study period Goal. This study aims at describing the sociodemographic characteristics, risk factors and biological parameters of patients admitted for kidney failure.

RESULTS

We selected 60 patients. The average age was 51, 38 + / _ 13, 47 with the most affected included age group between 50-59 years. 51, 67% had completed secondary education and 40% higher. Risk factors of renal damage were the HTA 66, 64%, 25% diabetes mellitus, use of nephrotoxic products 35%, HIV infection 11, 67%, 10% obesity, sickle cell disease 3, 3%. The birth weight birth of our patients as well as existing renal disease in family were unknown factors. 85% of our patients had hemoglobin levels below 12 g%.

CONCLUSION

From this observation, it appears that the age of our patients did not differ from that observed in other low-income communities. The level of education of our patients is higher compared to other studies. It would be better to develop strategies for early detection of kidney disease to avoid ending hemodialysis remains a very expensive treatment.

Associations of estimated glomerular filtration rate and blood urea nitrogen with incident coronary heart disease: the Dongfeng-Tongji Cohort Study

Estimated glomerular filtration rate (eGFR) has been reported to be associated with risk of incident coronary heart disease (CHD), and blood urea nitrogen (BUN) has been shown to be a strong predictor of mortality in patients with heart failure (HF). However, such epidemiological evidence from Chinese population was still limited. We used Cox proportional-hazards regression models to investigate the associations of eGFR and BUN with risk of incident CHD in the prospective Dongfeng-Tongji (DFTJ) cohort. After fully adjusted for potential confounders, a 10-unit decline in eGFR was associated with higher risk for CHD (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.01-1.09); compared with individuals with normal eGFR levels (eGFR ≥ 90 ml/min per 1.73 m2), individuals with a mild-to-severe eGFR decline (15 to 60 ml/min per 1.73 m2) were at significantly greater risk for CHD (HR 1.25, 95% CI 1.05-1.48; P = 0.011). Compared with individuals in the lowest tertile of BUN, those in the highest tertile were at significantly greater risk for CHD (HR 1.17, 95% CI 1.03-1.33; P = 0.014). In conclusion, a mild-to-severe decline in eGFR or a raised level of BUN might be associated with increased risk of incident CHD in middle-aged and elderly Chinese populations.

The association between urbanization and reduced renal function: findings from the China Health and Nutrition Survey

BACKGROUND

While chronic kidney disease (CKD) is a growing public health concern in low- and middle-income countries, such as China, few studies have investigated the association between urbanization and the occurrence of CKD in those countries.

METHODS

We investigated the association between urbanization and estimated glomerular filtration rate (eGFR), an important CKD risk marker. Data came from the China Health and Nutrition Survey wave 2009, in which we collected fasting serum, individual and household data along with community level urbanization data, which was used to derive a study-specific urbanization measure, in 218 communities across nine provinces. A total of 3644 men and 4154 women participants aged 18 years or older were included in the analysis. Reduced renal function was defined as eGFR of less than 60 mL/min/1.73 m2 measured using serum creatinine concentration (mg/dL).

RESULTS

After adjusting for socio-demographic (e.g., age, education and household income), a sex-stratified multilevel logistic model revealed that living in a more urbanized community was associated with higher odds of reduced eGFR (odds ratio [OR] = 1.38 per one-standard deviation [SD] increase in the CHNS specific urbanization index, 95% confidence interval [CI] = 1.11-1.73 for men; OR = 1.35, 95% CI = 1.11-1.62 for women). After adjusting for behavioral variables (i.e., alcohol consumption, smoking, physical activity and diet), as well as obesity and cardiometabolic risk factors, the association was attenuated in men (OR = 1.25, 95% CI = 0.98-1.59), but remained statistically significant in women (OR = 1.24, 95% CI = 1.01-1.52).

CONCLUSION

Our findings suggest that living in an urban environment is linked with higher odds of reduced renal function independently of behavioral and cardiometabolic risk factors, which have been shown to increase along with urbanization.

Association of Urinary Activity of MMP-2 with Microalbuminuria in an Isolated Sample of Subjects Living in High Altitude Rural Locations in México

Hernández-Hernández, Magda Elena, Jaime Morales-Romero, Clara Luz Sampieri, Diego Jesús Luna Lozano, Isidra del Carmen Valencia Lezama, Mónica Janett Muñoz Contreras, and Arturo Rodríguez Hernández. Association of urinary activity of MMP-2 with microalbuminuria in an isolated sample of subjects living in high altitude rural locations in México. High Alt Med Biol. 18:209-218, 2017.-Matrix metalloproteinases (MMP) are implicated in remodeling of the renal extracellular matrix. In a cross-sectional study we evaluated renal impairment in general population of high-altitude rural locations in México. Multivariable analysis was performed to identify the association between MMP-2 and MMP-9 and microalbuminuria. Twenty-eight (20.9%) subjects with renal impairment (WRI) and 106 (79.1%) without renal impairment were included. No differences were found relating to sex, location, marital status, current habits, weight, height, body mass index, waist size in males, creatinine in males, and uric acid. In contrast, differences were found among age, level of education, waist size in general and in females, creatinine in general and in females, urinary albumin, urea, glucose, total cholesterol, and triglycerides. Proportions of hypertension, type 2 diabetes mellitus, central abdominal obesity, hypertriglyceridemia, and hypercholesterolemia were greater in the group WRI. Presence of urinary MMP-2 or of both urinary gelatinases and arbitrary unit (AU) values ≥P₉₀ were associated with microalbuminuria. We conclude that AU values ≥P₉₀ of urinary MMP-2 (OR = 20.1, p = 0.002) is associated with microalbuminuria.

Innovative non-invasive model for screening reduced estimated glomerular filtration rate in a working population

AIM

Most of the existing risk scores for identifying people with reduced estimated glomerular filtration rate (eGFR) involve laboratory-based factors, which are not convenient and cost-effective to use in a large population-based screening programme. We aimed at using non-invasive variables to identify subjects with reduced eGFR in a Chinese working population.

METHODS

Two study populations were recruited in 2012 and 2015, respectively. The 2012 study population (n = 14 374) was randomly separated as the training dataset (n = 9621) or the internal testing dataset (n = 4753) at a ratio of 2:1, and the 2015 study population (n = 4371) was used as the external testing dataset. Stepwise logistic regression analysis with age, gender, hypertension and body mass index (BMI) status were first performed in the training dataset and then validated in both internal and external testing dataset. A nomogram was further developed based on the final model.

RESULTS

Results showed that older females with higher BMI status were more likely to have reduced eGFR. The model had excellent discrimination (AUC: 0.887 [95%CI: 0.865, 0.909] in the internal validation and 0.880 [95%CI: 0.829, 0.931] in the external validation) and calibration (Hosmer-Lemeshow test, P = 0.798 and 0.397 for internal and external dataset, respectively). The probability of having reduced eGFR increased gradually from <0.1% at a total score of 0 to 26% at a total score of 58 shown in the nomogram.

CONCLUSION

Non-invasive variables could help identify individuals at high risk of reduced eGFR for further kidney function testing or intervention, aiding in decision-making and resource allocation in large population screening.

Global Prevalence of Chronic Kidney Disease - A Systematic Review and Meta-Analysis

Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems and is an independent risk factor for cardiovascular disease (CVD). All stages of CKD are associated with increased risks of cardiovascular morbidity, premature mortality, and/or decreased quality of life. CKD is usually asymptomatic until later stages and accurate prevalence data are lacking. Thus we sought to determine the prevalence of CKD globally, by stage, geographical location, gender and age. A systematic review and meta-analysis of observational studies estimating CKD prevalence in general populations was conducted through literature searches in 8 databases. We assessed pooled data using a random effects model. Of 5,842 potential articles, 100 studies of diverse quality were included, comprising 6,908,440 patients. Global mean(95%CI) CKD prevalence of 5 stages 13·4%(11·7-15·1%), and stages 3-5 was 10·6%(9·2-12·2%). Weighting by study quality did not affect prevalence estimates. CKD prevalence by stage was Stage-1 (eGFR>90+ACR>30): 3·5% (2·8-4·2%); Stage-2 (eGFR 60-89+ACR>30): 3·9% (2·7-5·3%); Stage-3 (eGFR 30-59): 7·6% (6·4-8·9%); Stage-4 = (eGFR 29-15): 0·4% (0·3-0·5%); and Stage-5 (eGFR<15): 0·1% (0·1-0·1%). CKD has a high global prevalence with a consistent estimated global CKD prevalence of between 11 to 13% with the majority stage 3. Future research should evaluate intervention strategies deliverable at scale to delay the progression of CKD and improve CVD outcomes.

Prevalence, awareness, and treatment of anemia in Chinese patients with nondialysis chronic kidney disease: First multicenter, cross-sectional study

This was the first multicenter, cross-sectional survey to assess the prevalence of anemia, patient awareness, and treatment status in China. Data of patients with chronic kidney disease (CKD; age, 18-75 years; both out- and inpatients) from 25 hospitals in Shanghai, seeking medical treatment at the nephrology department, were collected between July 1, 2012 and August 31, 2012. The prevalence, awareness, and treatment of anemia in patients with nondialysis CKD (ND-CKD) were assessed. Anemia was defined as serum hemoglobin (Hb) levels ≤12 g/dL in women and ≤13 g/dL in men. A total of 2420 patients with ND-CKD were included. Anemia was established in 1246 (51.5%) patients: 639 (51.3%) men and 607 (48.7%) women. The prevalence of anemia increased with advancing CKD stage (χtrend = 675.14, P < 0.001). Anemia was more prevalent in patients with diabetic nephropathy (68.0%) than in patients with hypertensive renal damage (56.6%) or chronic glomerulonephritis (46.1%, both P < 0.001). Only 39.8% of the anemic patients received treatment with erythropoietin and 27.1% patients received iron products; furthermore, 22.7% of the patients started receiving treatment when their Hb level reached 7 g/dL. The target-achieving rate (Hb at 11-12 g/dL) was only 8.2%. Of the 1246 anemia patients, only 7.5% received more effective and recommended intravenous supplementation. Anemia is highly prevalent in patients with ND-CKD in China, with a low target-achieving rate and poor treatment patterns. The study highlights the need to improve multiple aspects of CKD management to delay the progression of renal failure.

Anthropometric measurements and markers of renal function in adults and older adults

Objective: To determine whether anthropometric indicators are associated with markers of renal function in adults and older adults. Methods: This cross-sectional study included 279 adults and older adults attending eight primary healthcare units in eastern Goiânia, Góias. Sociodemographic, lifestyle, and clinical data were collected using a standard questionnaire. Body mass index was categorized as overweight (≥25 kg/m²) or non-overweight. Waist circumference was classified as normal or high; chronic kidney disease was defined as a glomerular filtration rate below 60 mL/minutes/1.73 m²; micro/macroalbuminuria was defined as an albumin/creatinine ratio above 30 mg/g. The association between anthropometric indicators and renal function markers was assessed by multiple linear regression analysis. Results: Chronic kidney disease was present in 8.9% and micro/macroalbuminuria in 34.8% of the sample. The prevalence of overweight was 57.0%. Waist circumference and body mass index were positively associated with glomerular filtration rate, characterized as glomerular hyperfiltration. Microalbuminuria was positively associated with body mass index in women. Conclusion: The prevalences of chronic kidney disease and overweight were high in the study population. Overweight was positively associated with glomerular filtration rate.

Hypoxia: The Force that Drives Chronic Kidney Disease

In the United States the prevalence of end-stage renal disease (ESRD) reached epidemic proportions in 2012 with over 600,000 patients being treated. The rates of ESRD among the elderly are disproportionally high. Consequently, as life expectancy increases and the baby-boom generation reaches retirement age, the already heavy burden imposed by ESRD on the US health care system is set to increase dramatically. ESRD represents the terminal stage of chronic kidney disease (CKD). A large body of evidence indicating that CKD is driven by renal tissue hypoxia has led to the development of therapeutic strategies that increase kidney oxygenation and the contention that chronic hypoxia is the final common pathway to end-stage renal failure. Numerous studies have demonstrated that one of the most potent means by which hypoxic conditions within the kidney produce CKD is by inducing a sustained inflammatory attack by infiltrating leukocytes. Indispensable to this attack is the acquisition by leukocytes of an adhesive phenotype. It was thought that this process resulted exclusively from leukocytes responding to cytokines released from ischemic renal endothelium. However, recently it has been demonstrated that leukocytes also become activated independent of the hypoxic response of endothelial cells. It was found that this endothelium-independent mechanism involves leukocytes directly sensing hypoxia and responding by transcriptional induction of the genes that encode the β2-integrin family of adhesion molecules. This induction likely maintains the long-term inflammation by which hypoxia drives the pathogenesis of CKD. Consequently, targeting these transcriptional mechanisms would appear to represent a promising new therapeutic strategy.

Glucose intolerance associated with hypoxia in people living at high altitudes in the Tibetan highland

OBJECTIVES

To clarify the association between glucose intolerance and high altitudes (2900-4800 m) in a hypoxic environment in Tibetan highlanders and to verify the hypothesis that high altitude dwelling increases vulnerability to diabetes mellitus (DM) accelerated by lifestyle change or ageing.

DESIGN

Cross-sectional epidemiological study on Tibetan highlanders.

PARTICIPANTS

We enrolled 1258 participants aged 40-87 years. The rural population comprised farmers in Domkhar (altitude 2900-3800 m) and nomads in Haiyan (3000-3100 m), Ryuho (4400 m) and Changthang (4300-4800 m). Urban area participants were from Leh (3300 m) and Jiegu (3700 m).

MAIN OUTCOME MEASURE

Participants were classified into six glucose tolerance-based groups: DM, intermediate hyperglycaemia (IHG), normoglycaemia (NG), fasting DM, fasting IHG and fasting NG. Prevalence of glucose intolerance was compared in farmers, nomads and urban dwellers. Effects of dwelling at high altitude or hypoxia on glucose intolerance were analysed with the confounding factors of age, sex, obesity, lipids, haemoglobin, hypertension and lifestyle, using multiple logistic regression.

RESULTS

The prevalence of DM (fasting DM)/IHG (fasting IHG) was 8.9% (6.5%)/25.1% (12.7%), respectively, in all participants. This prevalence was higher in urban dwellers (9.5% (7.1%)/28.5% (11.7%)) and in farmers (8.5% (6.1%)/28.5% (18.3%)) compared with nomads (8.2% (5.7%)/15.7% (9.7%)) (p=0.0140/0.0001). Dwelling at high altitude was significantly associated with fasting IHG+fasting DM/fasting DM (ORs for >4500 and 3500-4499 m were 3.59/4.36 and 2.07/1.76 vs <3500 m, respectively). After adjusting for lifestyle change, hypoxaemia and polycythaemia were closely associated with glucose intolerance.

CONCLUSIONS

Socioeconomic factors, hypoxaemia and the effects of altitudes >3500 m play a major role in the high prevalence of glucose intolerance in highlanders. Tibetan highlanders may be vulnerable to glucose intolerance, with polycythaemia as a sign of poor hypoxic adaptation, accelerated by lifestyle change and ageing.

Prevalence of Hypertension in a Tribal Land Locked Population at High Altitude

Introduction. Extensive pubmed search reveals paucity of data on prevalence of hypertension in tribal population at high altitude. The data is all the more scarce from our part of India. Studies among tribal populations at high altitudes provide an interesting epidemiological window to study human evolution and adaptation to hypobaric hypoxia. Material and Methods. 401 participants above the age of 20 years were evaluated for blood pressure using a stratified simple random technique among villages located at high altitude. Results. Out of a total of 401 individuals studied 43 (males: 35; females: 8) were identified as hypertensive yielding a crude prevalence of 10.7%. The prevalence was higher in males (35/270; 12.9%) as compared to females (8/131; 6%). Prevalence was the highest in the age group of 30-39 among males (16/35; 45.7%) while it was the highest in the age group of 40-49 among females (7/8; 87%). Conclusions. Prevalence of 10.5% is noteworthy when interpreted in light of prevalence of hypertension in general population especially if hypobaric hypoxia is considered to have a protective effect on blood pressure in high altitude native populations.