Urbanization and kidney function decline in low and middle income countries

Epidemiology and referral patterns of patients living with chronic kidney disease in Johannesburg, South Africa: A single centre experience

Chronic kidney disease (CKD) is a significant contributor to the global burden of non-communicable disease. Early intervention may facilitate slowing down of progression of CKD; recognition of at-risk patient groups may improve detection through screening. We retrospectively reviewed the clinical records of 960 patients attending a specialist nephrology outpatient clinic during the period 1 January 2011-31 December 2021. A significant proportion (47.8%) of patients were referred with established CKD stage G4 or G5. Non-national immigration status, previous diagnosis with diabetes, and advancing age were associated with late referral; antecedent diagnosis with HIV reduced the odds of late referral. Black African patients comprised most of the sample cohort and were younger at referral and more frequently female than other ethnicities; non-nationals were younger at referral than South Africans. Hypertension-associated kidney disease was the leading ascribed aetiological factor for CKD (40.7% of cases), followed by diabetic kidney disease (DKD) (19%), glomerular disease (12.5%), and HIV-associated kidney disease (11.8%). Hypertension-related (25.9%) and diabetic (10.7%) kidney diseases were not uncommon in people living with HIV. Advancing age and male sex increased the likelihood of diagnosis with hypertensive nephropathy, DKD and obstructive uropathy; males were additionally at increased risk of HIV-associated kidney disease and nephrotoxin exposure, as were patients of Black African ethnicity. In summary, this data shows that hypertension, diabetes, and HIV remain important aetiological factors in CKD in the South African context. Despite the well-described risk of CKD in these disorders, referral to nephrology services occurs late. Interventions and policy actions targeting at-risk populations are required to improve referral practices.

Associations between heat waves and chronic kidney disease in China: The modifying role of land cover

The increasing frequency of heat waves under the global urbanization and climate change background poses elevating risks of chronic kidney disease (CKD). Nevertheless, there has been no evidence on associations between long-term exposures to heat waves and CKD as well as the modifying effects of land cover patterns. Based on a national representative population-based survey on CKD covering 47,086 adults and high spatial resolution datasets on temperature and land cover data, we found that annual days of exposure to heat waves were associated with increased odds of CKD prevalence. For one day/year increases in HW_975_4d (above 97.5 % of annual maximum temperature and lasting for at least 4 consecutive days), the odds ratio (OR) of CKD was 1.14 (95 %CI: 1.12, 1.15). Meanwhile, stronger associations were observed in regions with lower urbanicity [rural: 1.14 (95 %CI: 1.12, 1.16) vs urban: 1.07 (95 %CI: 1.03, 1.11), Pinteraction < 0.001], lower water body coverage [lower: 1.14 (95 %CI: 1.12, 1.16) vs higher: 1.02 (95 %CI: 0.98, 1.05), Pinteraction < 0.001], and lower impervious area coverage [lower: 1.16 (95 %CI: 1.14, 1.18) vs higher: 1.06 (95 %CI: 1.03, 1.10), Pinteraction = 0.008]. In addition, this study found disparities in modifying effects of water bodies and impervious areas in rural and urban settings. In rural regions, the associations between heat waves and CKD prevalence showed a consistent decreasing trend with increases in both proportions of water bodies and impervious areas (Pinteraction < 0.05). Nevertheless, in urban regions, we observed significant effect modification by water bodies, but not by impervious areas. Our study indicates the need for targeted land planning as part of adapting to the kidney impacts of heat waves, with a focus on urbanization in rural regions, as well as water body construction and utilization in both rural and urban regions.

Urban living and chronic diseases in the presence of economic growth: Evidence from a long-term study in southeastern China

High-speed urban development has brought about an increase in per capita income in low- and middle-income countries (LMICs) as well as the high prevalence rate of chronic diseases. Based on a study of chronic diseases from 2011 to 2021 in southeastern China, we used multivariate adjusted logistic regression method to analyze the effect of urban living on the incidence of typical chronic diseases and the trend of such effect with the improvement of public healthcare system. We adopted potential mediating risk factors of urban lifestyles including body mass index (BMI), frequency of dining out, sedentary time, and psychological distress in the adjusted estimation. Baseline results indicate a positive relationship between living in urban areas and the prevalence of type 2 diabetes, hyperlipidemia, and hypertension. Regarding the mediating factors, psychological distress had the highest positive coefficient (Cr) on type 2 diabetes, hyperlipidemia, and hypertension (Cr: 0.4881-0.7084), followed by BMI (Cr: 0.1042-0.1617) and frequency of dining out (Cr: 0.0311-0.0478), and finally, sedentary time (Cr: 0.0103-0.0147). However, regression results on the follow-up survey reveal that trend in the impact of living in urban areas on chronic disease diminished as the level of the healthcare system improved. Additionally, urban living was more positively correlated with the incidence of metabolic disease than with the incidence of cardiovascular disease and cancer. Our findings provide empirical evidence that future urban health planning in LMICs should pay sustained attention to upgrading the level of public health infrastructure covering urban residents as well as rural-to-urban migrants, constructing a long-term dynamic system of chronic disease prevention and control, and regularly monitoring the mental health problems of residents in order to interrupt the process of urban chronic disease prevalence in an early stage.

Social, political and legal determinants of kidney health: Perspectives from lower- and middle-income countries with a focus on India

The social determinants of health (SDoH) are the non-medical factors that influence kidney health outcomes directly or indirectly in a substantial manner and include conditions in which people are born, grow, work, live, and age. Many such challenges in lower- and middle- income countries have an unfavourable impact on kidney health. These conditions potentially influence economic policies and systems, development agendas, social norms, social policies, and political systems. In addition, many political and legal factors also determine and modify the ultimate outcome in patients with kidney disease. Legal factors that ensure universal health care, promote gender and racial equality, prevent malpractices and regulate strict laws in the field of kidney transplantation are the paramount determinants for the provision of necessary kidney care. Converging lines of evidence have supported the impact of social variables such as socioeconomic resources, social inclusion, housing conditions, educational attainment, and financial status on kidney health, particularly affect vulnerable and disadvantaged groups and result in challenges in kidney care delivery. Furthermore, the climate is an important SDoH that plays a crucial role in the occurrence, prevalence, and progression of kidney diseases as highlighted by the presence of higher prevalence of chronic kidney disease in hot tropical countries. The rising incidence of water and vector-borne diseases causing acute kidney injury is another consequence of disruptive environmental and climate change which is detrimental to kidney health. Political risk factors such as conflict also have a devastating influence on kidney health. The relationship between SDoH and kidney health outcomes requires more clarity. Gaps in the current knowledge need to be identified to inform the development of appropriate interventions to address upstream socio-economic risk factors for kidney disease.

Occupational Heat Exposure as a Risk Factor for End-Stage Kidney Disease: A Case-Control Study

OBJECTIVE

More patients are reaching end-stage kidney disease without evident cause. This study aims to explore occupational risk factors associated with hemodialysis.

METHODS

A multicenter matched case-control study included dialysis patients and age, sex, and diabetes-matched controls (normal kidney function). Conditional logistic regression analysis assessed occupational factors associated with dialysis.

RESULTS

Two hundred thirty eight hemodialysis patients and 238 controls were included. History of occupational heat exposure (odds ratio [OR] = 1.93; 95% confidence interval [CI]: 1.24 to 3.00), working as a cook (OR = 12; 95% CI: 1.56 to 92.29), as construction worker (OR = 10; 95% CI: 1.28 to 78.12) were associated with higher risk of dialysis. These results were significant in men and in those with kidney disease of unknown etiology.

CONCLUSIONS

Occupational heat exposure was found to be associated with hemodialysis. This is an important step for future development of preventive strategies in high-risk professions.

Urbanization, ambient air pollution, and prevalence of chronic kidney disease: A nationwide cross-sectional study

An increasing number of studies have linked ambient air pollution to chronic kidney disease (CKD) prevalence. However, its potential effect modification by urbanization has not been investigated. Based on data of 47,204 adults from the China National Survey of Chronic Kidney Disease (CKSCKD) dataset, night light satellite remote sensing data and high-resolution air pollution inversion products, the present cross-sectional study investigated the association between fine particulate matter <2.5 mm in diameter (PM_2.5), nitrogen dioxide (NO₂), night light index (NLI) and CKD prevalence in China, and the effect modification by urbanization characterized by administrative classification and NLI on the pollutant-health associations. Our results showed that a 10-μg/m³ increase in PM_2.5 at 3-year moving average, a 10-μg/m³ increase in NO₂ at 5-year moving average, and a 10-U increase in NLI at 5-year moving average were significantly associated with increased odds of CKD prevalence [OR = 1.24 (95 %CI:1.14, 1.35); OR = 1.12 (95 %CI:1.09, 1.15); OR = 1.05 (95 %CI:1.02, 1.07)]. Meanwhile, the pollutant-health associations were more apparent in medium-urbanized areas compared to low- and high-urbanized areas. For instance, a 10-μg/m³ increase in PM_2.5 concentration at 2-year moving average was associated with increased odds of CKD in the areas with NLI level in the second [OR = 2.78 (95 %CI:1.77, 4.36)] and third quartiles [OR = 1.49 (95 %CI:1.14, 1.95)], compared to the lowest [OR = 0.96 (95% CI: 0.73, 1.26)] and highest [OR = 0.63 (95% CI: 0.39-1.02)] quartiles. PM_2.5 and NO₂ were associated with increased odds of CKD prevalence, especially in areas with medium NLI levels, suggesting the necessity of strengthening environmental management in medium-urbanized regions.

High Incidence of Chronic Kidney Disease among Iranian Diabetic Adults: Using CKD-EPI and MDRD Equations for Estimated Glomerular Filtration Rate

BACKGROUND

To investigate the population based incidence rate of chronic kidney disease (CKD) and its potential risk factors among Iranian diabetic adults during over 14 years of follow-up.

METHODS

Two different equations (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] and Modification of Diet in Renal Disease [MDRD]) were applied for the calculating the estimated glomerular filtration rate (eGFR). Among a total of 1,374 diabetic Tehranian adults, 797 and 680 individuals were eligible for CKD-EPI and MDRD analyses, respectively. CKD was defined as eGFR lower than 60 mL/min/1.73 m2. Multivariable Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CI) for all potential risk factors.

RESULTS

The incidence rates (95% CI) of CKD per 1,000 person-years were 43.84 (39.49 to 48.66) and 55.80 (50.29 to 61.91) based on CKD-EPI and MDRD equations, respectively. Being older, a history of cardiovascular disease, and having lower levels of eGFR were significant risk factors in both equations. Moreover, in CKD-EPI, using glucose-lowering medications and hypertension, and in MDRD, female sex and fasting plasma glucose ≥10 mmol/L were also independent risk factors. Regarding the discrimination index, CKD-EPI equation showed a higher range of C-index for the predicted probability of incident CKD in the full-adjusted model, compared to MDRD equation (0.75 [0.72 to 0.77] vs. 0.69 [0.66 to 0.72]).

CONCLUSION

We found an incidence rate of more than 4%/year for CKD development among our Iranian diabetic population. Compared to MDRD, it can be suggested that CKD-EPI equation can be a better choice to use for prediction models of incident CKD among the Iranian diabetic populations.

Agro-economic and socio-environmental assessments of food and virtual water trades of Iran

Ending hunger and ensuring food security are among targets of 2030's SDGs. While food trade and the embedded (virtual) water (VW) may improve food availability and accessibility for more people all year round, the sustainability and efficiency of food and VW trade needs to be revisited. In this research, we assess the sustainability and efficiency of food and VW trades under two food security scenarios for Iran, a country suffering from an escalating water crisis. These scenarios are (1) Individual Crop Food Security (ICFS), which restricts calorie fulfillment from individual crops and (2) Crop Category Food Security (CCFS), which promotes "eating local" by suggesting food substitution within the crop category. To this end, we simulate the water footprint and VW trades of 27 major crops, within 8 crop categories, in 30 provinces of Iran (2005-2015). We investigate the impacts of these two scenarios on (a) provincial food security (FSp) and exports; (b) sustainable and efficient blue water consumption, and (c) blue VW export. We then test the correlation between agro-economic and socio-environmental indicators and provincial food security. Our results show that most provinces were threatened by unsustainable and inefficient blue water consumption for crop production, particularly in the summertime. This water mismanagement results in 14.41 and 8.45 billion m3 y-1 unsustainable and inefficient blue VW exports under ICFS. "Eating local" improves the FSp value by up to 210% which lessens the unsustainable and inefficient blue VW export from hotspots. As illustrated in the graphical abstract, the FSp value strongly correlates with different agro-economic and socio-environmental indicators, but in different ways. Our findings promote "eating local" besides improving agro-economic and socio-environmental conditions to take transformative steps toward eradicating food insecurity not only in Iran but also in other countries facing water limitations.

Cohort profile: protocol and baseline survey for the Shanghai Suburban Adult Cohort and Biobank (SSACB) study

PURPOSE

The Shanghai Suburban Adult Cohort and Biobank (SSACB) was established to identify environmental, lifestyle and genetic risk factors for non-communicable chronic diseases (NCDs) in adults (20-74 years old) living in a suburban area of Shanghai with rapid urbanisation.

PARTICIPANTS

Two of eight suburban district were purposely selected according to participant willingness, health service facilities, population, geographic region and electronic medical record system. From these suburban districts, four communities were selected based on economic level and population size. At stage three, one-third of the committees/villages were randomly selected from each community. All residents aged 20-74 years old were invited as study participants.

FINDINGS TO DATE

The baseline data on demographics, lifestyle and physical health-related factors were collected using a face-to-face questionnaire interview. All participants completed physical examinations and had blood and urine tests. Blood and urine samples from these tests were stored in a biobank. From 6 April 2016 through 31 October 2017, we conducted face-to-face interviews and clinical examinations in 44 887 participants: 35 727 from Songjiang District and 9160 from Jiading District. The average age of participants was 56.4±11.2 years in Songjiang and 56.6±10.5 years in Jiading. The prevalence of hypertension, diabetes and dyslipidaemia was 34.0%, 8.2% and 11.1%, respectively.

FUTURE PLANS

In-person surveys will be conducted every 5 years. For annual tracking, baseline data was linked to the local health information system, which was composed of an electronic medical record system, a chronic disease management system, a cancer registry system, an infectious disease report system and a death registry system. The data of the SSACB cohort is located in the School of Public Health, Fudan University. International and domestic collaborative research projects are encouraged and inherent in the project.

Prevalence and Risk Factors of CKD in South Kivu, Democratic Republic of Congo: A Large-Scale Population Study

Background

The prevalence of chronic kidney disease (CKD) in African American individuals is high but whether this applies to native populations in sub-Saharan Africa is unclear.

Methods

In a cross-sectional study, we assessed the prevalence and risk factors of CKD in rural and urban adults in South Kivu, Democratic Republic of Congo. Glomerular filtration rate (GFR) was estimated using the CKD–Epidemiology Collaboration (CKD-EPI) equations based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or both markers (eGFRcr-cys), without ethnic correction factor. CKD was defined as an eGFR <60 ml/min per 1.73 m² and/or albuminuria (albumin-to-creatinine ratio ≥30 mg/g).

Results

A total of 1317 participants aged 41.1 ± 17.1 years (730 rural, 587 urban) were enrolled. The prevalence of hypertension (20.2%; 95% confidence interval [CI], 18–22.3), diabetes mellitus (4.3%; 95% CI, 3.2–5.4) and obesity (8.9%; 95% CI, 7.4–10.5) was higher in urban than rural participants (all P < 0.05). HIV infection prevalence was 0.41% (95% CI, 0.05–0.78). The prevalence of eGFRcr <60 ml/min per 1.73 m² was 5.4% (95% CI, 4.2–6.7). The prevalence of albuminuria was 6.6% (95 % CI, 5.1–8.1). The overall prevalence of CKD was 12.2% (95% CI, 10.2–14.2) according to CKD-EPIcr. Factors independently associated with CKD-EPIcr were older age (adjusted odds ratio [aOR], 1.05 [1.04–1.07]), urban residence (aOR 1.86 [1.18–2.95]), female sex (aOR 1.66 [1.04–2.66]), hypertension (aOR 1.90 [1.15–3.12]), diabetes (aOR 2.03 [1.02–4.06]), and HIV infection (10.21 [2.75–37.85]). The results based on eGFRcys or eGFRcr-cys were largely consistent with the preceding.

Conclusion

Overall, the burden of CKD is substantial (>11%), predominantly in the urban area, and largely driven by classic risk factors (gender, aging, HIV, hypertension, and diabetes).

Housing Insecurity and Risk of Adverse Kidney Outcomes

Background

Housing insecurity is characterized by high housing costs or unsafe living conditions that prevent self-care and threaten independence. We examined the relationship of housing insecurity and risk of kidney disease.

Methods

We used longitudinal data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (Baltimore, MD). We used multivariable regression to quantify associations between housing insecurity and rapid kidney function decline (loss of >5 ml/min per 1.73 m² of eGFR per year) and, among those without kidney disease at baseline, incident reduced kidney function (eGFR <60 ml/min per 1.73 m²) and incident albuminuria (urine albumin-creatinine ratio [ACR] ≥30 mg/g).

Results

Among 1262 participants, mean age was 52 years, 40% were male and 57% were black. A total of 405 (32%) reported housing insecurity. After a median of 3.5 years of follow-up, rapid kidney function decline, incident reduced kidney function, and incident albuminuria occurred in 199 (16%), 64 (5%), and 74 (7%) participants, respectively. Housing insecurity was associated with increased odds of incident albuminuria (unadjusted OR, 2.04; 95% CI, 1.29 to 3.29; adjusted OR, 3.23; 95% CI, 1.90 to 5.50) but not rapid kidney function decline or incident reduced kidney function.

Conclusions

In this urban population, housing insecurity was associated with increased risk of subsequent albuminuria. Increased recognition of housing insecurity as a social determinant of kidney disease is needed, and risk-reduction efforts that specifically target populations experiencing housing insecurity should be considered.

Individual and Environmental Factors Associated with Proteinuria in Korean Children: A Multilevel Analysis

Proteinuria is a significant sign of childhood renal disorders. However, little is known about how sociodemographic and environmental factors are related to the presence of proteinuria among children and adolescents. This paper focuses on the prevalence of proteinuria and its risk factors among children and adolescents. This study conducted a secondary analysis of data from the 2016 Sample Schools Raw Data of Health Examination for School Students (SSRDHESS). Data collected from 27,081 students who had undergone a health screening were analyzed using Chi-square tests, independent t-tests, and multilevel logistic regression analysis. The prevalence of proteinuria was higher in the thin group than in the normal weight group (adjusted odds ratio (aOR) = 1.77; 95% confidence interval (CI) = 1.34–2.33) and lower in the overweight/obese group (aOR = 0.64; 95% CI = 0.51–0.80). Additionally, those in metropolitan and small–medium sized cities had a proteinuria prevalence about 1.5-fold higher than that of those in rural areas (95% CI = 1.08–2.02, 95% CI = 1.19–1.92, respectively). Proteinuria was associated with environmental pollution, including smoking rate, ambient particulate matter and heavy metals in drinking water (aOR = 1.10; 95% CI = 1.01–1.20; aOR = 1.06; 95% CI = 1.01–1.11, aOR = 1.001; 95% CI = 1.0001–1.0015). These results suggest that to improve health management effectiveness, kidney disease prevention efforts for children and adolescents should focus on geographical area and environmental pollution, as well as body weight as individual factors.