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

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.

Scoliosis among children in Qinghai-Tibetan Plateau of China: A cross-sectional epidemiological study

Background

The average altitude of Qinghai-Tibetan Plateau is 4,500 m and most of the residents are Tibetan ethnicity. The purpose of this study was to investigate the prevalence of scoliosis and associated factors among children in this region through a scoliosis screening program.

Methods

A cross-sectional study was preformed between May 2020 and December 2020 in Qinghai-Tibetan Plateau. A total of 9,856 children aged 6-17 years from schools and nearby villages were screened using visual inspection, the Adams forward-bending test, the angle of trunk rotation, and radiography. A self-designed questionnaire was used to collect demographic data. The prevalence of scoliosis and associated factors were analyzed.

Results

The overall prevalence of scoliosis among children in Qinghai-Tibetan Plateau was 3.69%, with 5.38% for females and 2.11% for males. The prevalence of scoliosis was 3.50% in children resided below 4,500 m while 5.63% in those resided above 4,500 m (P = 0.001). The prevalence of congenital scoliosis (2.14 vs. 0.42%, P < 0.001) and neuromuscular scoliosis (0.34 vs. 0.07%, P = 0.041) were significantly higher in the altitude above 4,500 m. 50.00% of patients resided above 4,500 m were recommended for surgery while 16.24% in those resided below 4,500 m (P < 0.001). Independent associated factors were detected as female (OR = 2.217, 95 CI% 1.746-2.814, P < 0.001), BMI < 18.5 (OR = 1.767, 95 CI% 1.441-2.430, P = 0.005), altitude of residence ≥ 4,500 m (OR = 1.808, 95 CI% 1.325-2.483, P = 0.002), and sleep time < 8 h (OR = 2.264, 95 CI% 1.723-2.846, P = 0.001).

Conclusion

The prevalence of scoliosis among children in Qinghai-Tibetan Plateau was 3.69%. With increasing altitudes, the prevalence of scoliosis and its major type were different from that at lower altitudes. Female, BMI < 18.5, altitude of residence ≥ 4,500 m, and sleep time < 8 h were independently associated with the prevalence of this disease. Early screening should be carried out before the age of 7 years, especially in the high-altitude, underdeveloped, and rural areas.

Results of a community-based screening programme for chronic kidney disease and associated risk factors, (obesity, diabetes and hypertension) in a Samoan cohort

OBJECTIVES

In 2019, under the World Kidney Day theme of 'Kidney health for everyone everywhere', the National Kidney Foundation of Samoa undertook an extensive community screening campaign to detect the estimated prevalence of chronic kidney disease (CKD) and its associated risk factors in the community.

SETTING

Fifteen screening sites, with 11 urban and rural sites on the main island of Upolu, and 4 in different rural areas on the island of Savaii.

PARTICIPANTS

All participants were self-referrals to the various screening sites. In total, 1163 Samoans were screened, with similar numbers from both urban and rural areas and similar numbers of female and male.

SCREENING ACTIVITIES

All participants were screened for CKD using point of care serum creatinine determinations, with calculation of estimated glomerular filtration rate using the CKD-EPI formula and dipstix urinalysis. A standardised screening survey was used to capture demographic and medical history with associated risk factors of obesity, diabetes, using point of care determination of HbA1c and hypertension. Logistic regression was used to investigate the association of CKD with risk factors.

RESULTS

In total, 1163 people were screened for CKD within the month of March 2019. The prevalance of CKD (grades 1-5) was 44.5% (95% CI 41.6% to 47.4) with individual grade prevalence CKD 1: 3.7%, CKD 2: 6.1%, CKD 3: 30.7%, CKD 4: 2.9% and CKD 5: 1.0%. The prevalence of obesity (body mass index ≥32), diabetes and hypertension was 66.3%, 30.8% and 54.3%, respectively.

CONCLUSIONS

This is the first paper to report the estimated prevalence of CKD in Samoa or any other Pacific Island nation. It reveals an urgent need for further studies on the epidemiology of CKD in Samoa, to develop country-specific prevention strategies to mitigate this growing burden and prevent subsequent CKD associated complications including development of kidney failure and premature death.

Correlation and Diagnostic Value of Serum RBP4 and sRAGE and the Condition of Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive damage of renal structure and function caused by various reasons. Its course is long and irreversible. CKD can be divided into 5 stages according to the glomerular filtration rate (GFR). Early detection and early intervention of CKD can reduce the complications of patients and improve the survival rate. Retinol-binding protein 4 (RBP4) is a small molecule transporter. Receptor for advanced glycation end products (RAGE) is a multi-ligand transmembrane signal transduction receptor discovered in recent years. Soluble RAGE (sRAGE) is a new splicing heterogeneity of RAGE. Our results show that serum RBP4 is increased while sRAGE is decreased in CKD patients, both of which are closely related to the severity of CKD. The combined use of serum RBP4 and sRAGE has a high diagnostic value for CKD and can provide a reliable diagnostic basis for the clinic.

Distinguishing feature of gut microbiota in Tibetan highland coronary artery disease patients and its link with diet

The prevalence of coronary artery disease (CAD) in Tibetan Highlanders is lower than that in plain-living individuals, but the mechanism still unclear. Gut microbiota (GM) disorder is considered one of the potential factors involved in the pathogenesis of CAD, but the GM characteristics of Tibetan Highlanders suffering from CAD are unknown. We sequenced the V3-V4 region of the 16S ribosomal RNA of gut bacteria from fecal samples from Tibetan and Han CAD patients and healthy individuals inhabiting the Qinghai-Tibet Plateau, as well as from Han CAD patients and healthy individuals living at sea level, and we analyzed the GM characteristics of these subjects by bioinformatics analysis. The results showed that Tibetan Highlanders suffering from CAD had higher GM α-diversity, with differently distributed cluster compared with healthy Tibetan Highlanders and Han CAD patients living at high and low altitudes. Genera Catenibacterium, Clostridium_sensu_stricto, Holdemanella, and Ruminococcus 2 were enriched in Tibetan Highlanders suffering from CAD compared with healthy Tibetan Highlanders and Han CAD patients living at high- and low-altitudes. Prevotella was enriched in Tibetan Highlanders suffering from CAD compared with Han CAD patients living at high- and low-altitudes. Moreover, Catenibacterium was positively correlated with Prevotella. Additionally, Catenibacterium, Holdemanella, and Prevotella were positively correlated with fermented dairy product, carbohydrate and fiber intake by the subjects, while Clostridium_sensu_stricto was negatively correlated with protein intake by the subjects. In conclusion, our study indicated that Tibetan Highlanders suffering from CAD showed distinct GM, which was linked to their unique dietary characteristics and might associated with CAD.

Stereoacuity and its determinants in 7-year-old children: the Lhasa Childhood Eye Study

PURPOSE

To explore the distribution of stereoacuity and to examine its determinants in school-age children in Tibetan plateau, Southwest China.

METHODS

This is the cross-sectional part of a school-based cohort study of 7-year-old children in Lhasa, Tibet Autonomous Region, Southwest China. Children in first year of primary school were invited to undergo a comprehensive examination, including height, weight, visual acuity, cycloplegic autorefraction (1% cyclopentolate), anterior segment, cover and uncover test, and stereoacuity (Titmus Stereo Test).

RESULTS

A total of 1833 eligible subjects were included, with a mean age of 6.82 ± 0.46 years. Mean stereoacuity was 1.78 ± 0.21 in log units (median: 60 arcsec). Children with stereoacuity equal to 40 arcsec and stereoacuity worse than 100 arcsec accounted for 29.24% and 8.18% of the cohort, respectively. Tibetan ethnicity (OR = 1.98; 95%CI, 1.30-3.03), astigmatism (OR = 1.65; 95%CI, 1.26-2.17), strabismus (OR = 2.92; 95%CI, 1.38-6.18), and amblyopia (OR = 3.77; 95%CI, 1.14-12.49) were risk factors for normal stereoacuity (= 40 arcsec). Shorter height, younger age, strabismus, and worse BCVA (P < 0.05 for all) were both related to lower stereoacuity in Spearman correlation analysis and associated with lower stereoacuity in multivariate regression analysis.

CONCLUSION

Stereoacuity maturation does not appear fully completed in 7-year-old children, while few children present stereoacuity worse than 100 arcsec (8.18%). Lower stereoacuity was associated with younger age, shorter height, strabismus, and lower best-corrected visual acuity.

High-resolution age-specific mapping of the two-week illness prevalence rate based on the National Health Services Survey and geostatistical analysis: a case study in Guangdong province, China

BACKGROUND

The two-week illness prevalence rate is an important and comparable indicator of health service needs. High-spatial-resolution, age-specific risk mapping of this indicator can provide valuable information for health resource allocation. The age-prevalence relationships may be different among areas of the study region, but previous geostatistical models usually ignored the spatial-age interaction.

METHODS

We took Guangdong province, the province with the largest population and economy in China, as a study case. We collected two-week illness data and other potential influencing predictors from the fifth National Health Services Survey in 2013 and other open-access databases. Bayesian geostatistical binary regression models were developed with spatial-age structured random effect, based on which, high-resolution, age-specific two-week illness prevalence rates, as well as number of people reporting two-week illness, were estimated. The equality of health resource distribution was further evaluated based on the two-week illness mapping results and the health supply data.

RESULTS

The map across all age groups revealed that the highest risk was concentrated in the central (i.e., Pearl River Delta) and northern regions of the province. These areas had a two-week illness prevalence > 25.0%, compared with 10.0-20.0% in other areas. Age-specific maps revealed significant differences in prevalence between age groups, and the age-prevalence relationships also differed across locations. In most areas, the prevalence rates decrease from age 0 to age 20, and then increase gradually. Overall, the estimated age- and population-adjusted prevalence was 16.5% [95% Bayesian credible interval (BCI): 14.5-18.6%], and the estimated total number of people reporting illness within the two-week period was 17.5 million (95% BCI: 15.5-19.8 million) in Guangdong Province. The Lorenz curve and the Gini coefficient (resulted in 0.3526) showed a moderate level of inequality in health resource distribution.

CONCLUSIONS

We developed a Bayesian geostatistical modeling framework with spatial-age structured effect to produce age-specific, high-resolution maps of the two-week illness prevalence rate and the numbers of people reporting two-week illness in Guangdong province. The methodology developed in this study can be generalized to other global regions with available relevant survey data. The mapping results will support plans for health resource allocation.

Prevalence of abnormal kidney function in a rural population of Benin and associated risk factors

BACKGROUND

The global burden of kidney disease has increased in recent years worldwide. Risk factors for kidney disease are common in Africa, but data on their prevalence are lacking. This study aims to determine the prevalence of abnormal kidney function and associated factors among participants included in the TAnve HEalth Study (TAHES) cohort in Benin.

METHODS

This was a cross-sectional study nested within the TAHES cohort. It was carried out in 2019, among TAHES participants aged 25 years and above, living in Tanvè and Dékanmè, two villages located in southwestern Benin. Data on risk factors were collected using the World Health Organization's STEPS questionnaire. Anthropometric measurements and capillary creatinine measurements were performed. Abnormal kidney function was defined as a low glomerular filtration rate (< 60 mL/min/1.73 m2).

RESULTS

Creatinine was measured among 1360 out of the 1583 participants in the cohort in 2019. The median age was 39 [32-53]. The prevalence of abnormal kidney function was 16.10%; 95%CI = [14.15-18.05]. The results of the multivariate logistic regression showed that the probability of abnormal kidney function increased significantly with age (adjusted OR (aOR) = 2.75; 95%CI = [1.83-4.14]), female gender (aOR = 2; 95%CI = [1.37-2.91]), hypertension (aOR = 1.54; 95%CI = [1.12-2.13]), high body mass index (aOR = 1, 56; 95%CI = [1.12-2.17]) and hyperglycemia (aOR = 2.86; 95%CI = [1.68-4.88]).

CONCLUSION

The prevalence of abnormal kidney function was high. These data should guide national authorities and help to raise community awareness of the benefits of early detection of this condition.

Assessment of serum electrolytes and kidney function test for screening of chronic kidney disease among Ethiopian Public Health Institute staff members, Addis Ababa, Ethiopia

BACKGROUND

Chronic kidney disease (CKD), which is characterized by its asymptomatic nature until an end stage, is one of the most common public health problems in the world. Thus, a regular checkup, especially for those individuals with high risk groups is inevitably important, and the screening has been done with laboratory findings. However, in developing countries, including Ethiopia screening for CKD are rarely done, and it is becoming common to hear sudden death from the kidney failure. Therefore, we aimed to screen serum electrolyte levels and estimated glomerular filtration rate (eGFR) among Ethiopian Public Health Institute (EPHI) staff members for an early detection of CKD and to identify the factors associated with it.

METHODS

A cross-sectional study was conducted from July 1 to October 28, 2018 among EPHI staff members. The level of serum creatinine and electrolytes were measured using COBAS 6000 analyzer. Then, eGFR was calculated using MDRD and CKD-EPI equations. Data analysis were done using SPSS version 20, and the factors associated with the outcome variable were assessed using logistic regression. P values < 0.05 were considered as statistically significant.

RESULTS

This study found that 3.6 and 1.9% of the study participants were at CKD stage II by MDRD and CKD-EPI equations, respectively. Out of the total study participants, 9.5% had hyperkalemia (serum potassium level > 5.0 mmol/L) and 8.5% had hypocalcemia (serum calcium level < 2.15 mmol/L). An older age (P = 0.006), high BMI (P = 0.045) and previous history of CVDs (P = 0.033) were found to be significantly associated factors with reduced glomerular filtration rate. Nine percent of the study participants were obese, 6.1% had family history of kidney failure, 18% self-reported history of hypertension, 3.4% diabetic and 5.3% had CVDs. About 51.2% of the study participants were males, and the majorities, (66%) of the study participants were found to be alcohol consumers.

CONCLUSIONS

The prevalence of a stage II kidney disease was relatively low and none of the participants was under serious kidney disease (GFR < 60 mmol/min/1.73m2). An older age, high BMI and previous history of CVDs were significantly associated with reduced GFR. Hyperkalemia and hypokalemia were the major electrolyte disorders in the study participants.

Risk factors for subclinical renal damage and its progression: Hanzhong Adolescent Hypertension Study

BACKGROUND/OBJECTIVES

Chronic kidney disease (CKD) is a global public health problem, including in China. The aim of this study was to identify the risk factors for the development and progression of subclinical renal disease (SRD) in a Chinese population. We also examined whether the impact of the risk factors on SRD changed over time.

SUBJECTS/METHODS

To identify the predictors of SRD, we performed a cross-sectional study of the 2432 subjects in our Hanzhong Adolescent Hypertension Cohort. A subgroup of 202 subjects was further analyzed over a 12-year period from 2005 to 2017 to determine the risk factors for the development and progression of SRD.

RESULTS

In cross-sectional analysis, elevated blood pressure, male gender, diabetes, body mass index, and triglyceride were independently associated with a higher risk of SRD. In longitudinal analysis, an increase in total cholesterol over a 4-year period and an increase in serum triglyceride over a 12-year period were independently associated with progression of albuminuria. Finally, increases in both total cholesterol and serum uric acid over a 4-year follow-up showed an independent association with a modest reduction in estimated glomerular filtration rate (eGFR).

CONCLUSIONS

In this study of a Chinese cohort, we show several metabolic abnormalities as independent risk factors for subclinical renal disease in a Chinese cohort. In addition, we demonstrate that the effects of total cholesterol, triglycerides and uric acid on the development and progression of albuminuria or the decline in eGFR vary at different points of follow-up. These findings highlight the importance of early detection of metabolic abnormalities to prevent SRD.

Prevalence of chronic kidney disease in Brazilians with arterial hypertension and/or diabetes mellitus

The present study aimed to evaluate the prevalence of chronic kidney disease (CKD) in individuals with arterial hypertension (AH) and/or diabetes mellitus (DM) accompanied by Primary Health Care (PHC) in Brazil. The estimated glomerular filtration rate (eGFR) based on creatinine, and urinary albumin-to-creatinine ratio (ACR) were measured in 841 subjects with AH and/or DM, followed by PHC in the city of Viçosa. The CKD was diagnosed according to KDIGO criteria. Sociodemographic, clinical, and anthropometric factors related to the prevalence of CKD were investigated through multiple logistic regression. The prevalence of hidden CKD was 15.4%. Of these, 7.5% were identified by albuminuria (ACR ≥30 mg/g) with slightly decreased eGFR. Age, baseline disease, waist circumference (WC), and systolic blood pressure remained associated with CKD after multivariate analysis. The two major risk factors for hidden CKD were the presence of AH in association with DM and an increase in age. Hidden CKD was more common within people with AH and DM, and with high WC, glycosylated hemoglobin, and serum phosphorus as well as male gender and decreased serum albumin. This knowledge of risk associations can help avoid progression to CKD.

Lhasa childhood eye study: the rationale, methodology, and baseline data of a 5 year follow-up of school-based cohort study in the Tibetan plateau region of Southwest China

Background

Tibetan Plateau is a highland area with special geographical location, time zone, and ethnic composition. We herein report the rationale, methodology and baseline data of the school-based childhood cohort study named Lhasa Childhood Eye Study (LCES), with the primary objective to pursue a comprehensive understanding on the longitudinal trends of refractive error as well as other ocular diseases and to address the differences between Tibetan Plateau and other parts of the world.

Methods

Grade one students from primary schools in Lhasa were cluster randomly selected. They were examined and would be conducted with follow-up annually for 5 years. The examination procedures for LCES consisted of standardized ocular, systematic examinations, and questionnaires, identical to the Anyang Childhood Eye Study (ACES) conducted in central China.

Results

One thousand nine hundred two Grade one students eligible for the LCES, 1856 (97.58%) participated in the study, with a mean age of 6.83 ± 0.46 years (range 5.89–10.32 years), and the proportions of male to be 53.02%. 1762 (94.93%) of the 1856 participants in the baseline exam were Tibetans. 1837 (98.98%) of the students examined had cycloplegic autorefraction performed. The numbers of hyperopia, emmetropia, myopia, and high myopia were 127 (6.91%), 1639 (89.22%), 71 (3.86%) and 3 (0.16%) respectively. Compared with ACES, students from LCES baseline had a younger age (p < 0.001), lower cycloplegic spherical equivalent (p < 0.001), similar myopia prevalence (p = 0.886), lower hyperopia prevalence (p < 0.001), and a higher emmetropia prevalence (p < 0.001).

Conclusions

LCES was a school-based cohort study in Tibetan Plateau with a high baseline response rate. A higher emmetropic trend was found in LCES compared with ACES. Continuous documentation of this cohort might potentially provide useful reference information for the areas of China which was previously not well studied.

Trial registration

The study has finished the clinical registration on Chinese Clinical Trial Registry. (ChiCTR1900026693).