Kidney damage and associated risk factors in rural and urban sub-Saharan Africa (AWI-Gen): a cross-sectional population study

Genetic association and transferability for urinary albumin-creatinine ratio as a marker of kidney disease in four Sub-Saharan African populations and non-continental individuals of African ancestry

Background

Genome-wide association studies (GWAS) have predominantly focused on populations of European and Asian ancestry, limiting our understanding of genetic factors influencing kidney disease in Sub-Saharan African (SSA) populations. This study presents the largest GWAS for urinary albumin-to-creatinine ratio (UACR) in SSA individuals, including 8,970 participants living in different African regions and an additional 9,705 non-resident individuals of African ancestry from the UK Biobank and African American cohorts.

Methods

Urine biomarkers and genotype data were obtained from two SSA cohorts (AWI-Gen and ARK), and two non-resident African-ancestry studies (UK Biobank and CKD-Gen Consortium). Association testing and meta-analyses were conducted, with subsequent fine-mapping, conditional analyses, and replication studies. Polygenic scores (PGS) were assessed for transferability across populations.

Results

Two genome-wide significant (P < 5 × 10-8) UACR-associated loci were identified, one in the BMP6 region on chromosome 6, in the meta-analysis of resident African individuals, and another in the HBB region on chromosome 11 in the meta-analysis of non-resident SSA individuals, as well as the combined meta-analysis of all studies. Replication of previous significant results confirmed associations in known UACR-associated regions, including THB53, GATM, and ARL15. PGS estimated using previous studies from European ancestry, African ancestry, and multi-ancestry cohorts exhibited limited transferability of PGS across populations, with less than 1% of observed variance explained.

Conclusion

This study contributes novel insights into the genetic architecture of kidney disease in SSA populations, emphasizing the need for conducting genetic research in diverse cohorts. The identified loci provide a foundation for future investigations into the genetic susceptibility to chronic kidney disease in underrepresented African populations Additionally, there is a need to develop integrated scores using multi-omics data and risk factors specific to the African context to improve the accuracy of predicting disease outcomes.

The New Creatinine-Based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 Equation: Potential Impact on Screening for Chronic Kidney Disease in an Asymptomatic Black African Population

BACKGROUND

In 2021, a new Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration equation was introduced that excluded race correction. We set out to compare estimated glomerular filtration rate (eGFR) determined using the creatinine-based CKD-EPI 2009 and 2021 equations and the reclassification of chronic kidney disease (CKD) eGFR staging to explore the potential ramifications of adopting the 2021 equation on reported eGFR and CKD staging.

METHODS

We analyzed secondary data previously utilized to determine reference intervals among Black African individuals residing in urban towns in Kenya. Serum creatinine was measured using a standardized modified Jaffé kinetic method on a Beckman AU5800 analyzer. Glomerular filtration rate (GFR) was estimated using both the 2009 and 2021 CKD-EPI creatinine equations. Classification of CKD based on eGFR was performed using the Kidney Disease: Improving Global Outcomes (KDIGO) practice guidelines.

RESULTS

Using 533 study samples, the median eGFR was highest when determined using the race-corrected CKD-EPI 2009 equation. The CKD-EPI 2021 equation yielded a median eGFR that was similar to the non-race-corrected CKD-EPI 2009 equation. The race-corrected CKD-EPI 2009 equation classified 93.6% of participants into CKD stage G1 compared with 85.6% by the CKD-EPI 2021 equation. The CKD-EPI 2021 equation classified 14.3% of participants into CKD stage G2 compared to 6.4% by the race-corrected CKD-EPI 2009 equation.

CONCLUSIONS

The CKD-EPI 2021 equation gave a comparable eGFR to the non-race-corrected CKD-EPI 2009 equation and its implementation in laboratories reporting eGFR in Kenya will help in identifying patients with an appropriate decrease in renal function.

Genetic Association and Transferability for Urinary Albumin-Creatinine Ratio as a Marker of Kidney Disease in four Sub-Saharan African Populations and non-continental Individuals of African Ancestry

BACKGROUND

Genome-wide association studies (GWAS) have predominantly focused on populations of European and Asian ancestry, limiting our understanding of genetic factors influencing kidney disease in Sub-Saharan African (SSA) populations. This study presents the largest GWAS for urinary albumin-to-creatinine ratio (UACR) in SSA individuals, including 8,970 participants living in different African regions and an additional 9,705 non-resident individuals of African ancestry from the UK Biobank and African American cohorts.

METHODS

Urine biomarkers and genotype data were obtained from two SSA cohorts (AWI-Gen and ARK), and two non-resident African-ancestry studies (UK Biobank and CKD-Gen Consortium). Association testing and meta-analyses were conducted, with subsequent fine-mapping, conditional analyses, and replication studies. Polygenic scores (PGS) were assessed for transferability across populations.

RESULTS

Two genome-wide significant (P<5x10-8) UACR-associated loci were identified, one in the BMP6 region on chromosome 6, in the meta-analysis of resident African individuals, and another in the HBB region on chromosome 11 in the meta-analysis of non-resident SSA individuals, as well as the combined meta-analysis of all studies. Replication of previous significant results confirmed associations in known UACR-associated regions, including THB53, GATM, and ARL15. PGS estimated using previous studies from European ancestry, African ancestry, and multi-ancestry cohorts exhibited limited transferability of PGS across populations, with less than 1% of observed variance explained.

CONCLUSION

This study contributes novel insights into the genetic architecture of kidney disease in SSA populations, emphasizing the need for conducting genetic research in diverse cohorts. The identified loci provide a foundation for future investigations into the genetic susceptibility to chronic kidney disease in underrepresented African populations Additionally, there is a need to develop integrated scores using multi-omics data and risk factors specific to the African context to improve the accuracy of predicting disease outcomes.

METHODS

Urine biomarkers and genotype data were obtained from two SSA cohorts (AWI-Gen and ARK), and two non-resident African-ancestry studies (UK Biobank and CKD-Gen Consortium). Association testing and meta-analyses were conducted, with subsequent fine-mapping, conditional analyses, and replication studies. Polygenic scores (PGS) were assessed for transferability across populations.

RESULTS

Two genome-wide significant (P<5x10-8) UACR-associated loci were identified, one in the BMP6 region on chromosome 6, in the meta-analysis of resident African individuals, and another in the HBB region on chromosome 11 in the meta-analysis of non-resident SSA individuals, as well as the combined meta-analysis of all studies. Replication of previous significant results confirmed associations in known UACR-associated regions, including THB53, GATM, and ARL15. PGS estimated using previous studies from European ancestry, African ancestry, and multi-ancestry cohorts exhibited limited transferability of PGS across populations, with less than 1% of observed variance explained.

CONCLUSION

This study contributes novel insights into the genetic architecture of kidney function in SSA populations, emphasizing the need for conducting genetic research in diverse cohorts. The identified loci provide a foundation for future investigations into the genetic susceptibility to chronic kidney disease in underrepresented African populations.

Chronic kidney disease of unknown aetiology in Africa: A review of the literature

During the last two decades, an epidemic of a severe form of chronic kidney disease (CKD) unrelated to traditional risk factors (diabetes and hypertension) has been recognized in low- to middle-income countries. CKD of unknown aetiology (CKDu) mainly affects young working-age adults, and has become as an important and devastating public health issue. CKDu is a multifactorial disease with associated genetic and environmental risk factors. This review summarizes the current epidemiological evidence on the burden of CKDu and its probable environmental risk factors contributing to CKD in Africa. PubMed/Medline and the African Journals Online databases were searched to identify relevant population-based studies published in the last two decades. In the general population, the burden of CKD attributable to CKDu varied from 19.4% to 79%. Epidemiologic studies have established that environmental factors, including genetics, infectious agents, rural residence, low socioeconomic status, malnutrition, agricultural practise and exposure to agrochemicals, heavy metals, use of traditional herbs, and contaminated water sources or food contribute to the burden of CKD in the region. There is a great need for epidemiological studies exploring the true burden of CKDu and unique geographical distribution, and the role of environmental factors in the development of CKD/CKDu.

Proteomic insights into the pathophysiology of hypertension-associated albuminuria: Pilot study in a South African cohort

BACKGROUND

Hypertension is an important public health priority with a high prevalence in Africa. It is also an independent risk factor for kidney outcomes. We aimed to identify potential proteins and pathways involved in hypertension-associated albuminuria by assessing urinary proteomic profiles in black South African participants with combined hypertension and albuminuria compared to those who have neither condition.

METHODS

The study included 24 South African cases with both hypertension and albuminuria and 49 control participants who had neither condition. Protein was extracted from urine samples and analysed using ultra-high-performance liquid chromatography coupled with mass spectrometry. Data were generated using data-independent acquisition (DIA) and processed using Spectronaut™ 15. Statistical and functional data annotation were performed on Perseus and Cytoscape to identify and annotate differentially abundant proteins. Machine learning was applied to the dataset using the OmicLearn platform.

RESULTS

Overall, a mean of 1,225 and 915 proteins were quantified in the control and case groups, respectively. Three hundred and thirty-two differentially abundant proteins were constructed into a network. Pathways associated with these differentially abundant proteins included the immune system (q-value [false discovery rate] = 1.4 × 10- 45), innate immune system (q = 1.1 × 10- 32), extracellular matrix (ECM) organisation (q = 0.03) and activation of matrix metalloproteinases (q = 0.04). Proteins with high disease scores (76-100% confidence) for both hypertension and chronic kidney disease included angiotensinogen (AGT), albumin (ALB), apolipoprotein L1 (APOL1), and uromodulin (UMOD). A machine learning approach was able to identify a set of 20 proteins, differentiating between cases and controls.

CONCLUSIONS

The urinary proteomic data combined with the machine learning approach was able to classify disease status and identify proteins and pathways associated with hypertension-associated albuminuria.

Hypertension Related Co-Morbidities and Complications in Women of Sub-Saharan Africa: A Brief Review

Hypertension is the leading cause of cardiovascular disease in women, and sub-Saharan African (SSA) countries have some of the highest rates of hypertension in the world. Expanding knowledge of causes, management, and awareness of hypertension and its co-morbidities worldwide is an effective strategy to mitigate its harms, decrease morbidities and mortality, and improve individual quality of life. Hypertensive disorders of pregnancy (HDPs) are a particularly important subset of hypertension, as pregnancy is a major stress test of the cardiovascular system and can be the first instance in which cardiovascular disease is clinically apparent. In SSA, women experience a higher incidence of HDP compared with other African regions. However, the region has yet to adopt treatment and preventative strategies for HDP. This delay stems from insufficient awareness, lack of clinical screening for hypertension, and lack of prevention programs. In this brief literature review, we will address the long-term consequences of hypertension and HDP in women. We evaluate the effects of uncontrolled hypertension in SSA by including research on heart disease, stroke, kidney disease, peripheral arterial disease, and HDP. Limitations exist in the number of studies from SSA; therefore, we will use data from countries across the globe, comparing and contrasting approaches in similar and dissimilar populations. Our review highlights an urgent need to prioritize public health, clinical, and bench research to discover cost-effective preventative and treatment strategies that will improve the lives of women living with hypertension in SSA.

Renal outcomes in adults with HBV, HIV and HBV/HIV coinfection after 3 years of antiviral therapy in urban Tanzania

BACKGROUND

An enhanced understanding of renal outcomes in persons with chronic HBV, HIV, and HBV/HIV coinfection is needed to mitigate chronic kidney disease in regions where HBV and HIV are endemic.

OBJECTIVES

To investigate changes in estimated glomerular filtration rate (eGFR) in adults with HBV, HIV or HBV/HIV enrolled in a 3 year prospective cohort study of liver outcomes in Dar es Salaam, Tanzania and initiated on antiviral therapy.

METHODS

We compared eGFR between and within groups over time using mixed-effects models.

RESULTS

Four hundred and ninety-nine participants were included in the analysis (HBV: 164; HIV: 271; HBV/HIV: 64). Mean baseline eGFRs were 106.88, 106.03 and 107.18 mL/min/1.73 m2, respectively. From baseline to Year 3, mean eGFR declined by 4.3 mL/min/1.73 m2 (95% CI -9.3 to 0.7) and 3.7 (-7.8 to 0.5) in participants with HBV and HIV, respectively, and increased by 5.1 (-4.7 to 14.9) in those with HBV/HIV. In multivariable models, participants with HBV had lower eGFRs compared with those with HIV or HBV/HIV and, after adjusting for HBV DNA level and hepatitis B e antigen (HBeAg) status, significantly lower eGFRs than those with HBV/HIV at all follow-up visits.

CONCLUSIONS

In this Tanzanian cohort, coinfection with HBV/HIV did not appear to exacerbate renal dysfunction compared with those with either infection alone. Although overall changes in eGFR were small, persons with HBV experienced lower eGFRs throughout follow-up despite their younger age and similar baseline values. Longer-term studies are needed to evaluate continuing changes in eGFR and contributions from infection duration and other comorbidities.

Water chemistry poses health risks as reliance on groundwater increases: A systematic review of hydrogeochemistry research from Ethiopia and Kenya

Reliance on groundwater is increasing in Sub-Saharan Africa as development programmes work towards improving water access and strengthening resilience to climate change. In lower-income areas, groundwater supplies are typically installed without water quality treatment infrastructure or services. This practice is underpinned by an assumption that untreated groundwater is typically suitable for drinking due to the relative microbiological safety of groundwater compared to surface water; however, chemistry risks are largely disregarded. This article systematically reviews groundwater chemistry results from 160 studies to evaluate potential health risk in two case countries: Ethiopia and Kenya. Most studies evaluated drinking water suitability, focusing on priority parameters (fluoride, arsenic, nitrate, or salinity; 18 %), pollution impacts (10 %), or overall suitability (45 %). The remainder characterised general hydrogeochemistry (13 %), flow dynamics (10 %), or water quality suitability for irrigation (3 %). Only six studies (4 %) reported no exceedance of drinking water quality thresholds. Thus, chemical contaminants occur widely in groundwaters that are used for drinking but are not regularly monitored: 78 % of studies reported exceedance of contaminants that have direct health consequences ranging from hypertension to disrupted cognitive development and degenerative disease, and 81 % reported exceedance of aesthetic parameters that have indirect health impacts by influencing perception and use of groundwater versus surface water. Nevertheless, the spatiotemporal coverage of sampling has substantial gaps and data availability bias is driven by a) the tendency for research to concentrate in areas with known water quality problems, and b) analytical capacity limitations. Improved in-country analytical capacity could bolster more efficient assessment and prioritisation of water chemistry risks. Overall, this review demonstrates that universal and equitable access to safe drinking water (Sustainable Development Goal target 6.1) will not be achieved without wider implementation of groundwater treatment, thus a shift is required in how water systems are designed and managed.

High Rates of Undiagnosed Target Organ Damage Among Adults with Elevated Blood Pressure or Diabetes Mellitus in a Community-Based Survey in Lesotho

INTRODUCTION

Prevalence of elevated blood pressure (BP) and diabetes mellitus (DM) is increasing in sub-Saharan Africa. Data on target organ damage such as retinopathy, left ventricular hypertrophy (LVH), renal impairment and peripheral neuropathy (PN) among persons with elevated BP and/or DM in sub-Saharan Africa remain scarce.

AIM

To determine at community-level the prevalence of retinopathy, LVH, renal impairment, and PN among adults with elevated BP and/or DM, and assess the association of elevated BP and/or DM with target organ damage in Lesotho.

METHODS

During a household-based survey, a sub-sample of adults with elevated BP (≥ 140/90 mmHg) and/or DM (glycosylated hemoglobin ≥ 6.5%), as well as comparators (BP < 140/90 mmHg, HbA1c < 6.5%) were screened for retinopathy, LVH, renal impairment, and PN. We used multivariable logistic regression for inferential analysis.

RESULTS

Out of 6108 participants screened during the survey, 420 with elevated BP only, 80 with DM only, 61 with elevated BP and DM, and 360 comparators were assessed for target organ damage. Among those with elevated BP, and among those with DM with or without elevated BP, prevalence of retinopathy was 34.6% (89/257) and 14.4% (15/104); renal impairment was 45.0% (156/347) and 42.4% (56/132), respectively. Among those with elevated BP, 2.3% (7/300) and 65.7% (224/341) had LVH and left ventricular concentric remodeling, respectively. PN, only assessed among those with DM, was present in 32.6% (42/129). Elevated BP was associated with increased odds of retinopathy (aOR, 19.13; 95% CI, 8.52-42.94; P < 0.001) and renal impairment (aOR, 1.80; 95% CI, 1.27-2.55; P = 0.001). Presence of both elevated BP and DM was associated with an increased odds of retinopathy (aOR, 16.30; 95%CI, 5.69-46.68; P < 0.001), renal impairment (aOR, 2.55; 95% CI, 1.35-4.81; P = 0.004), and PN (aOR, 2.13; 95% CI, 1.04-4.38; P = 0.040).

CONCLUSION

We found a high prevalence of undiagnosed target organ damage among adults with elevated BP and/or DM during community-based screening. These findings emphasize the importance of regular prevention and screening activities in this setting.

Forgotten but not gone in rural South Africa: Urinary schistosomiasis and implications for chronic kidney disease screening in endemic countries

Background: Urinary schistosomiasis caused by infection with Schistosoma haematobium ( S. haematobium) remains endemic in Africa and is associated with haematuria and albuminuria/proteinuria. Kidney Disease Improving Global Outcomes clinical guidelines recommend evaluating proteinuria/albuminuria and glomerular filtration rate for chronic kidney disease (CKD) diagnosis. The guidelines are informed by population data outside of Africa but have been adopted in many African countries with little validation. Our study aimed to characterise the burden of urinary schistosomiasis in rural South Africa (SA) and evaluate its relationship with markers of kidney dysfunction with implications for CKD screening. Methods: In this population-based cohort study, we recruited 2021 adults aged 20 - 79 years in the Mpumalanga Province, SA. Sociodemographic data were recorded, urinalysis performed, and serum creatinine and urine albumin and creatinine measured. Kidney dysfunction was defined as an estimated glomerular filtration rate (eGFR) <60ml/min/1.73m 2 and/or urine albumin-creatinine ratio >3.0mg/mmol. S . haematobium infection was determined by urine microscopy. Multivariable analyses were performed to determine relationships between S. haematobium and markers of kidney dysfunction. Results: Data were available for 1226 of 2021 participants. 717 (58.5%) were female and the median age was 35 years (IQR 27 - 47). Prevalence of kidney dysfunction and S. haematobium was 20.2% and 5.1% respectively. S. haematobium was strongly associated with kidney dysfunction (OR 8.66; 95% CI 4.10 - 18.3) and related to albuminuria alone (OR 8.69; 95% CI 4.11 - 18.8), with no evidence of an association with eGFR <90ml/min/1.73m 2 (OR 0.43; 95% CI 0.05 - 3.59). Discussion: The strong association between urinary schistosomiasis and albuminuria requires careful consideration when screening for CKD. Screening for, and treatment of, schistosomiasis should be a routine part of initial work-up for CKD in S. haematobium endemic areas. Urinary schistosomiasis, a neglected tropical disease, remains a public health concern in the Mpumulanga province of SA.

Forgotten but not gone in rural South Africa: Urinary schistosomiasis and implications for chronic kidney disease screening in endemic countries

Background: Urinary schistosomiasis caused by infection with Schistosoma haematobium ( S. haematobium) remains endemic in Africa and is associated with haematuria and albuminuria/proteinuria. Kidney Disease Improving Global Outcomes clinical guidelines recommend evaluating proteinuria/albuminuria and glomerular filtration rate for chronic kidney disease (CKD) diagnosis. The guidelines are informed by population data outside of Africa but have been adopted in many African countries with little validation. Our study aimed to characterise the burden of urinary schistosomiasis in rural South Africa (SA) and evaluate its relationship with markers of kidney dysfunction with implications for CKD screening. Methods: In this population-based cohort study, we recruited 2021 adults aged 20 - 79 years in the Mpumalanga Province, SA. Sociodemographic data were recorded, urinalysis performed, and serum creatinine and urine albumin and creatinine measured. Kidney dysfunction was defined as an estimated glomerular filtration rate (eGFR) <60ml/min/1.73m 2 and/or urine albumin-creatinine ratio >3.0mg/mmol. S . haematobium infection was determined by urine microscopy. Multivariable analyses were performed to determine relationships between S. haematobium and markers of kidney dysfunction. Results: Data were available for 1226 of 2021 participants. 717 (58.5%) were female and the median age was 35 years (IQR 27 - 47). Prevalence of kidney dysfunction and S. haematobium was 20.2% and 5.1% respectively. S. haematobium was strongly associated with kidney dysfunction (OR 8.66; 95% CI 4.10 - 18.3) and related to albuminuria alone (OR 8.69; 95% CI 4.11 - 18.8), with no evidence of an association with eGFR <90ml/min/1.73m 2 (OR 0.43; 95% CI 0.05 - 3.59). Discussion: The strong association between urinary schistosomiasis and albuminuria requires careful consideration when screening for CKD. Screening for, and treatment of, schistosomiasis should be a routine part of initial work-up for CKD in S. haematobium endemic areas. Urinary schistosomiasis, a neglected tropical disease, remains a public health concern in the Mpumulanga province of SA.

High rates of kidney impairment among older people (≥ 60 years) living with HIV on first-line antiretroviral therapy at screening for a clinical trial in Kenya

BACKGROUND

There is a paucity of data on kidney impairment among older people living with HIV (PLWH). We evaluated kidney function among PLWH age ≥ 60 years on first-line antiretroviral (ARV) therapy during screening for a clinical trial in Kenya.

METHODS

The bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) Elderly Study is an open-label, randomized, active-controlled, non-inferiority trial conducted at two sites in Kenya. Potential participants were screened for study entry if they were at least 60 years old, had been on ARVs for at least 24 weeks and had no history of treatment failure. At screening, participants had samples collected for serum creatinine and estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration 2021 equation.

RESULTS

Between January and April 2022, 714 participants were screened and had creatinine measured. All participants were black, 54.1% were female and the median age was 64 years (range 60 to 87 years). Most participants (666 [93.3%]) were on tenofovir disoproxil fumarate-containing regimens, 711 (99.6%) were on dolutegravir-containing regimens, and only 2 (0.3%) were on a regimen with a ritonavir-boosted protease inhibitor. Most participants (686 [96.6%]) were virally suppressed. Treatment for comorbidities was common, with 175 (24.5%) on treatment for hypertension and 39 (5.5%) on treatment for diabetes mellitus. The median eGFR was 64.7 mL/min/1.73m2, and 289 (40.5%) participants had an eGFR < 60 mL/min/1.73m2. In multivariate analysis, factors associated with lower eGFR were female gender (p<0.001), being on treatment for hypertension (p<0.001) and nadir CD4 count < 50 cells/μL (p = 0.008).

CONCLUSIONS

Our study identified high rates of impaired kidney function among elderly PLHW in Kenya, which highlights the importance of routine assessment of kidney function and the need to address modifiable risk factors, use of appropriate ARVs, and management of kidney disease in this population.

Chronic Kidney Disease Burden in Low-Resource Settings: Regional Perspectives

The burden of chronic kidney disease (CKD) has increased exponentially worldwide but more so in low- and middle-income countries. Specific risk factors in these regions expose their populations to an increased risk of CKD, such as genetic risk with APOL1 among populations of West African heritage or farmers with CKD of unknown etiology that spans various countries across several continents to immigrant/indigenous populations in both low- and high-income countries. Low- and middle-income economies also have the double burden of communicable and noncommunicable diseases, both contributing to the high prevalence of CKD. The economies are characterized by low health expenditure, sparse or nonexistent health insurance and welfare programs, and predominant out-of-pocket spending for medical care. This review highlights the challenges in populations with CKD from low-resource settings globally and explores how health systems can help ameliorate the CKD burden.

The prevalence of chronic kidney disease in South Africa - limitations of studies comparing prevalence with sub-Saharan Africa, Africa, and globally

BACKGROUND

Chronic kidney disease (CKD) is a globally significant non-communicable disorder. CKD prevalence varies between countries and within a country. We compared the prevalence rates of CKD in South Africa with sub-Saharan Africa, Africa, and globally.

METHODS

We registered a systematic review with the International Prospective Register of Systematic Reviews for prevalence studies reporting CKD stages III-V from 2013 to 2021. The analysis sought to explain any significant differences in prevalence rates. The R statistical package was used for data analysis. Comparisons included measures of effect size due to the large sample sizes analysed. We also compared sex differences in prevalence rates, common aetiologies, and type of study methodologies employed.

RESULTS

Eight studies were analysed, with two from each region. The matched prevalence rates of CKD between the various regions and South Africa showed significant differences, except for one comparison between South Africa and an African study [p = 0.09 (95% CI - 0.04-0.01)]. Both sub-Saharan African studies had a higher prevalence than South Africa. One study in Africa had a higher prevalence, while the other had a lower prevalence, whilst one Global study had a higher prevalence, and the other had a lower prevalence compared to South Africa. The statistical differences analysed using the Cramer's V test were substantially less than 0.1. Thus, differences in comparisons were largely due to differences in sample sizes rather than actual differences.

CONCLUSION

Variable prevalence rates between regions included disparities in sample size, definitions of CKD, lack of chronicity testing and heterogeneous laboratory estimations of eGFR. Improved consistency and enhanced methods for diagnosing and comparing CKD prevalence are essential.

Kidney dysfunction: prevalence and associated risk factors in a community-based study from the North West Province of South Africa

BACKGROUND

Globally, the World Health Organization ranks chronic kidney disease (CKD) as one of the top 10 causes of mortality. In South Africa, where noncommunicable diseases have become leading causes of mortality, the true population prevalence of CKD is unknown and associated risk factors remain understudied. This study aimed to describe the prevalence of kidney dysfunction and associated risk factors in a community from the North West province of South Africa.

METHODS

This cross-sectional study included 1999 participants older than 30 years. Kidney dysfunction was defined as (i) estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73m², or (ii) urine albuminuria-to-creatinine ratio (uACR) ≥ 3.0 mg/mmol, or a combination (i and ii). Risk factors included age, sex, urban/rural locality, body mass index (BMI), blood pressure (BP), lipid profile, haemoglobin A1c (HbA1C), C-reactive protein (CRP), gamma-glutamyl transferase (GGT), tobacco use, and HIV status.

RESULTS

Mean age of participants was 48 (42;56) years, and 655/1999 (33%) had eGFR < 90 ml/min/1.73m² and/or uACR ≥ 3.0 mg/mmol. Compared to those with normal kidney function, participants with eGFR < 90 ml/min/1.73m² and/or uACR ≥ 3.0 mg/mmol were older, female, had higher measures of adiposity, systolic, diastolic, and mean arterial blood pressure, serum lipids and C-reactive protein (CRP) (all p ≤ 0.024). In multiple regression analyses eGFR was associated with systolic BP (β = 0.11) and HIV infection (β = -0.09), and albuminuria was associated with elevated CRP (β = 0.12) and HIV infection (β = 0.11) (all p < 0.026). In both groups (individuals with and without kidney dysfunction respectively), eGFR was associated with age (β = -0.29, β = -0.49), male sex (β = 0.35, β = 0.28), BMI (β = -0.12, β = -0.09), low-density/high-density lipoprotein cholesterol ratio (β = -0.17, β = -0.09) and CRP (β = 0.10, β = 0.09) (all p < 0.005); and uACR was associated with female sex (β = 0.10, β = -0.14), urban locality (β = -0.11, β = -0.08), BMI (β = -0.11, β-0.11), and systolic BP (β = 0.27, β = 0.14) (all p < 0.017).

CONCLUSION

In this study from the North West province, South Africa, eGFR < 90 ml/min/1.73m² and/or uACR ≥ 3.0 mg/mmol was prevalent and associated with modifiable risk factors. The findings may inform screening strategies for kidney disease prevention, focusing on women, obesity, blood pressure control, dyslipidaemia, identifying and treating inflammation, and HIV diagnosis and treatment.

Demographic and clinical profile of black patients with chronic kidney disease attending a tertiary hospital in Johannesburg, South Africa

Background

The prevalence of chronic kidney disease (CKD) is increasing worldwide; black patients have an increased risk of developing CKD and end stage kidney disease (ESKD) at significantly higher rates than other races.

Methods

A cross sectional study was carried out on black patients with CKD attending the kidney outpatient clinic at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in South Africa, between September 2019 to March 2020. Demographic and clinical data were extracted from the ongoing kidney outpatient clinic records and interviews, and were filled in a questionnaire. Patients provided blood and urine for laboratory investigations as standard of care, and data were descriptively and inferentially entered into REDcap and analysed using STATA version 17. Multivariable logistic regression analysis was used to identify demographic and clinical variables associated with advanced CKD.

Results

A total of 312 black patients with CKD were enrolled in the study with a median age of 58 (IQR 46–67) years; 58% patients had advanced CKD, 31.5% of whom had grossly increased proteinuria, 96.7% had hypertension, 38.7% had diabetes mellitus and 38.1% had both hypertension and diabetes mellitus. In patients with advanced CKD, the median age was 61 (IQR 51–69) years, eGFR 33 (30–39) mL/min/1.73 m2, serum bicarbonate 22 (IQR 20–24), haemoglobin 12.9 (IQR 11.5–14.0) g/dl and serum uric acid 0.43 (IQR 0.37–0.53). The prevalence of metabolic acidosis was 62.4%, anemia 46.4% and gout 30.9% among those with advanced CKD, while the prevalence of metabolic acidosis and anaemia was 46.6% and 25.9% respectively in those with early CKD. Variables with higher odds for advanced CKD after multivariable logistic regression analysis were hypertension (OR 3.3, 95% CI 1.2–9.2, P = 0.020), diabetes mellitus (OR 1.8, 95% CI 1.1–3.3, P = 0.024), severe proteinuria (OR 3.5, 95% CI 1.9–6.5, P = 0.001), angina (OR 2.5, 95% CI 1.2–5.1, P = 0.008), anaemia (OR 2.9, 95% CI 1.7–4.9, P = 0.001), hyperuricemia (OR 2.4, 95% CI 1.4–4.1, P = 0.001), and metabolic acidosis (OR 2.0, 95% CI 1.2–3.1, P = 0.005). Other associations with advanced CKD were loss of spouse (widow/widower) (OR 3.2, 95% CI 1.4–7.4, P = 0.006), low transferrin (OR 2.4, 95% CI 1.1–5.1, P = 0.028), hyperkalemia (OR 5.4, 95% CI 1.2–24.1, P = 0.029), use of allopurinol (OR 2.4, 95% CI 1.4–4.3, P = 0.005) and doxazosin (OR 1.9, 95% CI 1.2–3.1, P = 0.006).

Conclusion

Hypertension and diabetes mellitus were strongly associated with advanced CKD, suggesting a need for primary and secondary population-based prevention measures. Metabolic acidosis, anemia with low transferrin levels, hyperuricemia and hyperkalemia were highly prevalent in our patients, including those with early CKD, and they were strongly associated with advanced CKD, requiring clinicians and dietitians to be proactive in supporting the needs of CKD patients in meeting their daily dietary requirements towards preventing and slowing the progression of CKD.

Measurement of kidney function in Malawi, South Africa, and Uganda: a multicentre cohort study

BACKGROUND

The burden of kidney disease in many African countries is unknown. Equations used to estimate kidney function from serum creatinine have limited regional validation. We sought to determine the most accurate way to measure kidney function and thus estimate the prevalence of impaired kidney function in African populations.

METHODS

We measured serum creatinine, cystatin C, and glomerular filtration rate (GFR) using the slope-intercept method for iohexol plasma clearance (mGFR) in population cohorts from Malawi, Uganda, and South Africa. We compared performance of creatinine and cystatin C-based estimating equations to mGFR, modelled and validated a new creatinine-based equation, and developed a multiple imputation model trained on the mGFR sample using age, sex, and creatinine as the variables to predict the population prevalence of impaired kidney function in west, east, and southern Africa.

FINDINGS

Of 3025 people who underwent measured GFR testing (Malawi n=1020, South Africa n=986, and Uganda n=1019), we analysed data for 2578 participants who had complete data and adequate quality measurements. Among 2578 included participants, creatinine-based equations overestimated kidney function compared with mGFR, worsened by use of ethnicity coefficients. The greatest bias occurred at low kidney function, such that the proportion with GFR of less than 60 mL/min per 1·73 m² either directly measured or estimated by cystatin C was more than double that estimated from creatinine. A new creatinine-based equation did not outperform existing equations, and no equation, including the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 race-neutral equation, estimated GFR within plus or minus 30% of mGFR for 75% or more of the participants. Using a model to impute kidney function based on mGFR, the estimated prevalence of impaired kidney function was more than two-times higher than creatinine-based estimates in populations across six countries in Africa.

INTERPRETATION

Estimating GFR using serum creatinine substantially underestimates the individual and population-level burden of impaired kidney function in Africa with implications for understanding disease progression and complications, clinical care, and service provision. Scalable and affordable ways to accurately identify impaired kidney function in Africa are urgently needed.

FUNDING

The GSK Africa Non-Communicable Disease Open Lab.

TRANSLATIONS

For the Luganda, Chichewa and Xitsonga translations of the abstract see Supplementary Materials section.

Bedside rationing and moral distress in nephrologists in sub- Saharan Africa

Background

Kidney diseases constitute an important proportion of the non-communicable disease (NCD) burden in Sub-Saharan Africa (SSA), though prevention, diagnosis and treatment of kidney diseases are less prioritized in public health budgets than other high-burden NCDs. Dialysis is not considered cost-effective, and for those patients accessing the limited service available, high out-of-pocket expenses are common and few continue care over time. This study assessed challenges faced by nephrologists in SSA who manage patients needing dialysis. The specific focus was to investigate if and how physicians respond to bedside rationing situations.

Methods

A survey was conducted among a randomly selected group of nephrologists from SSA. The questionnaire was based on a previously validated survey instrument. A descriptive and narrative approach was used for analysis.

Results

Among 40 respondents, the majority saw patients weekly with acute kidney injury (AKI) or end-stage kidney failure (ESKF) in need of dialysis whom they could not dialyze. When dialysis was provided, clinical compromises were common, and 66% of nephrologists reported lack of basic diagnostics and medication and > 80% reported high out-of-pocket expenses for patients. Several patient-, disease- and institutional factors influenced who got access to dialysis. Patients’ financial constraints and poor chances of survival limited the likelihood of receiving dialysis (reported by 79 and 78% of nephrologists respectively), while a patient’s being the family bread-winner increased the likelihood (reported by 56%). Patient and institutional constraints resulted in most nephrologists (88%) frequently having to make difficult choices, sometimes having to choose between patients. Few reported existence of priority setting guidelines. Most nephrologists (74%) always, often or sometimes felt burdened by ethical dilemmas and worried about patients out of hospital hours. As a consequence, almost 46% of nephrologists reported frequently regretting their choice of profession and 26% had considered leaving the country.

Conclusion

Nephrologists in SSA face harsh priority setting at the bedside without available guidance. The moral distress is high. While publicly funded dialysis treatment might not be prioritized in essential health care packages on the path to universal health coverage, the suffering of the patients, families and the providers must be acknowledged and addressed to increase fairness in these decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02827-2.

Association of impaired kidney function with mortality in rural Uganda: results of a general population cohort study

OBJECTIVE

To determine the association between baseline kidney function and subsequent all-cause mortality.

DESIGN AND SETTING

A general population-based cohort study from rural Uganda.

PARTICIPANTS

People aged 18 years and above with measured baseline estimated glomerular filtration rate (eGFR), recruited from survey rounds in 2011-2012 or 2014-2015 and followed up to March 2019.

OUTCOME MEASURE

The primary outcome was all-cause mortality, identified through reports from community health workers and verified by verbal autopsy. The association between baseline eGFR category and mortality was determined using multivariable Cox regression.

RESULTS

Of 5812 participants in both rounds, we included 5678 (97.7%) participants with kidney function and mortality data; the median age was 36 years (IQR 24-50), 60.7% were female, 10.3% were hypertensive, 9.8% were HIV-positive and 1.5% were diabetic. During a median follow-up of 5.0 years (IQR 3.7-6.0) there were 140 deaths. In age-adjusted and sex-adjusted analyses, eGFR <45 mL/min/1.73 m2 at baseline was associated with a 5.97 (95% CI 2.55 to 13.98) increased risk of mortality compared with those with baseline eGFR >90 mL/min/1.73 m2. After inclusion of additional confounders (HIV, body mass index, diabetes, hypertension, alcohol and smoking status) into the model, eGFR <45 mL/min/1.73 m2 at baseline remained strongly associated with mortality (HR 6.12, 95% CI 2.27 to 16.45), although the sample size fell to 3102. Test for trend showed strong evidence (p<0.001) that the rate of mortality increased progressively as the category of baseline kidney function decreased. When very high eGFR was included as a separate category in age-adjusted and sex-adjusted analyses, baseline eGFR ≥120 mL/min/1.73 m2 was associated with increased risk of mortality (HR 2.68, 95% CI 1.47 to 4.87) compared with the reference category of 90-119 mL/min/1.73 m2.

CONCLUSION

In a prospective cohort in rural Uganda we found that impaired baseline kidney function was associated with subsequently increased total mortality. Improved understanding of the determinants of kidney disease and its progression is needed in order to inform interventions for prevention and treatment.

"Validation of the D:A:D Chronic Kidney Disease Risk Score Incorporating Proteinuria in People Living with HIV in Harare, Zimbabwe"​​

OBJECTIVE

We sought to validate the D:A:D risk score for chronic kidney disease (CKD) in people living with HIV (PLWH) in a cohort from Harare, Zimbabwe. Additionally, we aimed to evaluate proteinuria as a predictive variable in the risk score model, being the first study to do so.

DESIGN

Data from PLWH attending a clinic in Harare was evaluated. Those with a baseline estimated glomerular filtration rate >60ml/min/1.73m2 and at least two subsequent eGFR measurements were included. A modified version of the D:A:D risk score model was applied to categorise participants as 'low', 'medium' and 'high-risk' of progression to CKD. Potential predictors of renal impairment were assessed by logistic regression in univariate and multivariate models. Proteinuria was evaluated in a nested model using D:A:D risk categories.

RESULTS

2793 participants were included. 40 participants (1.4% of the cohort) progressed to CKD during the median follow-up time of 4.2 years. Progression rates were 1%, 3% and 12% in the low, medium, and high-risk groups respectively. Proteinuria data was available for 2251 participants. Presence of proteinuria was strongly associated with progression to CKD [OR 7.8, 95% CI 3.9-15.7], and its inclusion in the risk score improved the discrimination of the model with the c-statistic increasing from 0.658 to 0.853).

CONCLUSION

A modified version of the D:A:D CKD risk score performed well in predicting CKD events among this Sub-Saharan African cohort of people living with HIV. Inclusion of proteinuria into the risk score model significantly improved predictability.

Carotid Atherosclerosis, Microalbuminuria, and Estimated 10-Year Atherosclerotic Cardiovascular Disease Risk in Sub-Saharan Africa

IMPORTANCE

Carotid atherosclerosis and microalbuminuria are associated with atherosclerotic cardiovascular disease (ASCVD) but are understudied in sub-Saharan Africa.

OBJECTIVE

To evaluate the association of carotid atherosclerosis and microalbuminuria with 10-year ASCVD risk in middle-aged sub-Saharan African individuals.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study conducted analyses of baseline data from the African-Wits-INDEPTH (International Network for the Demographic Evaluation of Populations and Their Health in Low- and Middle-Income Countries) genomic study (AWI-Gen). Women and men aged 40 to 60 years without baseline CVD and drawn from Burkina Faso, Ghana, Kenya, and South Africa were included.

MAIN OUTCOMES AND MEASURES

Hypotheses for the analyses were formulated after data collection. The main exposures were carotid atherosclerosis, assessed using carotid intima-media thickness (CIMT) using B-mode ultrasonography, and microalbuminuria, measured using spot urine albumin (SUA) and urine albumin-creatinine ratio (uACR). The main outcome was high ASCVD risk, defined as a 2018 Pooled Cohort Equations score of 7.5% or greater. Associations were estimated using adjusted multivariable logistic regression analyses.

FINDINGS

A total of 9010 participants with a mean (SD) age of 50 (6) years and 4533 (50.3%) women were included. High CIMT, SUA, and uACR were each associated with older age (eg, mean [SD] age of participants with high vs reference range CIMT: 55 [5] years vs 50 [6] years; P < .001) and high prevalence of both diabetes and hypertension (eg, hypertension among those with high vs reference range SUA: 213 of 1117 [19.1%] vs 356 of 2549 [14.0%]; P < .001). Smokers were likely to have higher vs reference range SUA (210 [18.8%] vs 407 [16.0%]) and uACR (138 of 707 [19.5%] vs 456 of 2797 [16.3%]). Carotid atherosclerosis was common in Burkina Faso (82 of 262 [31.3%]) and Ghana (91 [34.7%]), while microalbuminuria, measured by SUA, was common in Kenya (272 [24.4%]) and South Africa (519 [46.5%]). SUA was associated with higher odds of carotid atherosclerosis (odds ratio [OR], 1.77; 95% CI, 1.04-3.01) compared with uACR (OR, 0.51; 95% CI, 0.27-0.95). Common CIMT, SUA, and uACR were associated with 10-year ASCVD risk, with CIMT having a stronger association with 10-year ASCVD risk in both women (OR, 1.95; 95% CI, 1.78-2.14) and men (OR, 1.73; 95% CI, 1.55-1.93) than SUA (women: OR, 1.29; 95% CI, 1.12-1.43; men: OR, 1.46; 95% CI, 1.26-1.55) and uACR (women: OR, 1.32; 95% CI, 1.10-1.54; men: OR, 1.35; 95% CI, 1.15-1.46).

CONCLUSIONS AND RELEVANCE

The presence of microalbuminuria measured by SUA may indicate risk of subclinical carotid atherosclerosis and high 10-year ASCVD risk in middle-aged residents of sub-Saharan Africa. These data should be confirmed in longitudinal studies of cardiovascular events.

Expression of whole blood miR-126-3p, -30a-5p, -1299, -182-5p and -30e-3p in chronic kidney disease in a South African community-based sample

The burden of chronic kidney disease (CKD) in Africa remains poorly characterized, due partly to the lack of appropriate diagnostic strategies. Although in recent years the diagnostic and prognostic utility of microRNAs (miRNAs) have gained prominence in the context of CKD, its value has not been evaluated in African populations. We investigated the expression of whole blood miRNAs (miR-126-3p, -30a-5p, -1299, -182-5p and -30e-3p) in a total sample of 1449 comprising of 13.3% individuals with CKD (stage 1-5) and 26.4% male participants, as well as the association of these miRNAs with prevalent CKD, in a community-based sample of South African adults. We used Reverse Transcription Quantitative Real-Time PCR (RT-qPCR) to analyze miRNA expression. There was an increased expression in whole blood miR-126-3p, -30a-5p, -1299 and -182-5p in individuals with CKD, compared to those without (all p ≤ 0.036), whereas miR-30e-3p showed no significant difference between the groups (p = 0.482). Only miR-126-3p, -182-5p and -30e-3p were independently associated with increased risk of CKD (all p ≤ 0.022). This study showed for the first time that there is a dysregulation of whole blood miR-126-3p, -30a-5p, -1299 and -182-5p in South Africans of mixed-ancestry with CKD. More research is needed to ascertain their role in CKD risk screening in African populations.

Sickle Cell Trait and Kidney Disease in People of African Ancestry With HIV

Introduction

Sickle cell trait (SCT) has been associated with chronic kidney disease (CKD) in African Americans, although evidence for its impact in Africans and people with HIV is currently lacking. We conducted a cross-sectional study investigating the association between SCT and kidney disease in people of African ancestry with HIV in the UK.

Methods

The primary outcome was estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2. Secondary outcomes were eGFR <90 ml/min per 1.73 m2, end-stage kidney disease (ESKD; eGFR <15 ml/min per 1.73 m2, chronic dialysis, or having received a kidney transplant), proteinuria (protein-to-creatinine ratio >50 mg/mmol), and albuminuria (albumin-to-creatinine ratio >3 mg/mmol). Multivariable logistic regression was used to estimate the associations between SCT and kidney disease outcomes.

Results

A total of 2895 participants (mean age 48.1 [SD 10.3], 57.2% female) were included, of whom 335 (11.6%) had SCT and 352 (12.2%) had eGFR <60 ml/min per 1.73 m2. After adjusting for demographic, HIV, and kidney risk factors including APOL1 high-risk genotype status, individuals with SCT were more likely to have eGFR <60 ml/min per 1.73 m2 (odds ratio 1.62 [95% CI 1.14-2.32]), eGFR <90 ml/min per 1.73 m2 (1.50 [1.14-1.97]), and albuminuria (1.50 [1.09-2.05]). Stratified by APOL1 status, significant associations between SCT and GFR <60 ml/min per 1.73 m2, eGFR <90 ml/min per 1.73 m2, proteinuria, and albuminuria were observed for those with APOL1 low-risk genotypes.

Conclusion

Our results extend previously reported associations between SCT and kidney disease to people with HIV. In people of African ancestry with HIV, these associations were largely restricted to those with APOL1 low-risk genotypes.

Chronic kidney disease (CKD) and associated risk in rural South Africa: a population-based cohort study

Background: In Africa, true prevalence of chronic kidney disease (CKD) is unknown, and associated clinical and genetic risk factors remain understudied. This population-based cohort study aimed to investigate CKD prevalence and associated risk factors in rural South Africa. Methods: A total 2021 adults aged 20-79 years were recruited between 2017-2018 from the Agincourt Health and Socio-Demographic Surveillance System in Bushbuckridge, Mpumalanga, South Africa. The following were collected: sociodemographic, anthropometric, and clinical data; venous blood samples for creatinine, hepatitis B serology; DNA extraction; spot urine samples for dipstick testing and urine albumin: creatinine ratio (UACR) measurement. Point-of-care screening determined prevalent HIV infection, diabetes, and hypercholesterolemia. DNA was used to test for apolipoprotein L1 ( APOL1) kidney risk variants. Kidney Disease Improving Global Outcomes (KDIGO) criteria were used to diagnose CKD as low eGFR (<60mL/min/1.73m ²) and /or albuminuria (UACR ≥ 3.0mg/mmol) confirmed with follow up screening after at least three months. eGFR was calculated using the CKD-EPI _(creatinine) equation 2009 with no ethnicity adjustment. Multivariable logistic regression was used to model CKD risk. Results: The WHO age-adjusted population prevalence of CKD was 6.7% (95% CI 5.4 - 7.9), mostly from persistent albuminuria. In the fully adjusted model, APOL1 high-risk genotypes (OR 2.1; 95% CI 1.3 - 3.4); HIV infection (OR 1.8; 1.1 - 2.8); hypertension (OR 2.8; 95% CI 1.8 - 4.3), and diabetes (OR 4.1; 95% CI 2.0 - 8.4) were risk factors. There was no association with age, sex, level of education, obesity, hypercholesterolemia, or hepatitis B infection. Sensitivity analyses showed that CKD risk factor associations were driven by persistent albuminuria, and not low eGFR. One third of those with CKD did not have any of these risk factors. Conclusions:  In rural South Africa, CKD is prevalent, dominated by persistent albuminuria, and associated with APOL1 high-risk genotypes, hypertension, diabetes, and HIV infection.

Chronic kidney disease (CKD) and associated risk in rural South Africa: a population-based cohort study

Background: In Africa, true prevalence of chronic kidney disease (CKD) is unknown, and associated clinical and genetic risk factors remain understudied. This population-based cohort study aimed to investigate CKD prevalence and associated risk factors in rural South Africa. Methods: A total 2021 adults aged 20-79 years were recruited between 2017-2018 from the Agincourt Health and Socio-Demographic Surveillance System in Bushbuckridge, Mpumalanga, South Africa. The following were collected: sociodemographic, anthropometric, and clinical data; venous blood samples for creatinine, hepatitis B serology; DNA extraction; spot urine samples for dipstick testing and urine albumin: creatinine ratio (UACR) measurement. Point-of-care screening determined prevalent HIV infection, diabetes, and hypercholesterolemia. DNA was used to test for apolipoprotein L1 ( APOL1) kidney risk variants. Kidney Disease Improving Global Outcomes (KDIGO) criteria were used to diagnose CKD as low eGFR (<60mL/min/1.73m ²) and /or albuminuria (UACR ≥ 3.0mg/mmol) confirmed with follow up screening after at least three months. eGFR was calculated using the CKD-EPI _(creatinine) equation 2009 with no ethnicity adjustment. Multivariable logistic regression was used to model CKD risk. Results: The WHO age-adjusted population prevalence of CKD was 6.7% (95% CI 5.4 - 7.9), mostly from persistent albuminuria. In the fully adjusted model, APOL1 high-risk genotypes (OR 2.1; 95% CI 1.3 - 3.4); HIV infection (OR 1.8; 1.1 - 2.8); hypertension (OR 2.8; 95% CI 1.8 - 4.3), and diabetes (OR 4.1; 95% CI 2.0 - 8.4) were risk factors. There was no association with age, sex, level of education, obesity, hypercholesterolemia, or hepatitis B infection. Sensitivity analyses showed that CKD risk factor associations were driven by persistent albuminuria, and not low eGFR. One third of those with CKD did not have any of these risk factors. Conclusions:  In rural South Africa, CKD is prevalent, dominated by persistent albuminuria, and associated with APOL1 high-risk genotypes, hypertension, diabetes, and HIV infection.

Prevalence, incidence and predictors of renal impairment in persons with HIV receiving protease-inhibitors in rural Tanzania

Objective

Ritonavir-boosted protease inhibitors (bPI) in people living with HIV (PLWH) have been associated with renal impairment. Limited data are available from rural sub-Saharan Africa.

Methods

Using data from the Kilombero and Ulanga Antiretroviral Cohort Study (KIULARCO) in rural Tanzania from 2005-01/2020, we assessed the prevalence of renal impairment (estimated glomerular filtration rate <60 mL/min/1.73m2) at the time of switch from first-line antiretroviral treatment (ART) to bPI-regimen and the incidence of renal impairment on bPI. We assessed risk factors for renal impairment using logistic and Cox regression models.

Results

Renal impairment was present in 52/687 PLWH (7.6%) at the switch to bPI. Among 556 participants with normal kidney function at switch, 41 (7.4%) developed renal impairment after a median time of 3.5 (IQR 1.6–5.1) years (incidence 22/1,000 person-years (95%CI 16.1–29.8)). Factors associated with renal impairment at switch were older age (adjusted odds ratio (aOR) 1.55 per 10 years; 95%CI 1.15–2.11), body mass index (BMI) <18.5 kg/m² (aOR 2.80 versus ≥18kg/m²; 95%CI 1.28–6.14) and arterial hypertension (aOR 2.33; 95%CI 1.03–5.28). The risk of renal impairment was lower with increased duration of ART use (aOR 0.78 per one-year increase; 95%CI 0.67–0.91). The renal impairment incidence under bPI was associated with older age (adjusted hazard ratio 2.01 per 10 years; 95%CI 1.46–2.78).

Conclusions

In PLWH in rural sub-Saharan Africa, prevalence and incidence of renal impairment among those who were switched from first-line to bPI-regimens were high. We found associations between renal impairment and older age, arterial hypertension, low BMI and time on ART.

Risk factors associated with albuminuria in Rwanda: results from a STEPS survey

BACKGROUND

Non-communicable diseases (NCDs) are a growing burden which affects every part of the world, including developing countries. Chronic kidney disease (CKD) has varied etiology which can result from or complicate other NCDs such as diabetes and cardiovascular diseases. The growing prevalence of NCDs coupled with the increasing age in most developing countries, has seen a marked increase of CKD in these settings. CKD has been described as "the most neglected NCD" and greatly affects the quality of life of patients. It also places a huge economic burden on societies. However, few epidemiological data exist, particularly in sub-Saharan Africa. Assessment of the prevalence of albuminuria as a marker of kidney damage and CKD progression and its main risk factors was thus needed in Rwanda.

METHODS

This study analyzed data collected during the first STEPwise approach to NCD risk factor Surveillance (STEPS) survey in Rwanda, conducted from 2012 to 2013, to assess the prevalence of albuminuria. A multistage cluster sampling allowed to select a representative sample of the general population. Furthermore, descriptive, as well as univariable analyses and multiple logistic regression were performed to respond to the research question.

RESULTS

This survey brought a representative sample of 6,998 participants, among which 4,384 (62.65%) were female. Median age was 33 years (interquartile range, IQR 26-44), and over three quarters (78.45%) lived in rural areas. The albuminuria prevalence was 105.9 per 1,000 population. Overall, semi-urban and urban residency were associated with lower odds of CKD (odds ratio, OR 0.36, CI 0.23-0.56, p<0.001 and OR 0.34, CI 0.23-0.50, p<0.001, respectively) than rural status. Being married or living with a partner had higher odds (OR 1.44 (CI 1.03-2.02, p=0.031) and OR 1.62 (CI 1.06-2.48, p=0.026), respectively) of CKD than being single. Odds of positive albuminuria were also greater among participants living with human immunodeficiency virus (HIV) (OR 1.64, CI 1.09- 2.47, p=0.018). Gender, age group, smoking status and vegetable consumption, body mass index (BMI) and hypertension were not associated with albuminuria.

CONCLUSION

The albuminuria prevalence was estimated at 105.9 per 1,000 in Rwanda. Rural residence, partnered status and HIV positivity were identified as main risk factors for albuminuria. Increased early screening of albuminuria to prevent CKD among high-risk groups, especially HIV patients, is therefore recommended.

Epidemiology, risk factors, social determinants of health, and current management for non-alcoholic fatty liver disease in sub-Saharan Africa

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease globally and is estimated to affect approximately 25% of the world's population. Data about the prevalence and incidence of NAFLD in Africa are scarce, but the prevalence is estimated to be 13·5% for the general population. This is likely to be an underestimate considering the increasing burden of non-communicable diseases, particularly the rising prevalence of obesity and type 2 diabetes, driven by the overlapping challenges of food insecurity, nutritional transition, and associated increased consumption of calorie-dense foods. Establishing the true prevalence of NAFLD, raising public awareness around the risk factors behind the increase in NAFLD, and proactively addressing all components of metabolic syndrome will be important to combat this silent epidemic, which will have long-term health-care costs and economic consequences for the region.

The epidemiology of kidney disease in people of African ancestry with HIV in the UK

BACKGROUND

Chronic kidney disease (CKD) is a leading cause of morbidity and mortality globally. The risk of CKD is increased in people of African ancestry and with Human Immunodeficiency Virus (HIV) infection.

METHODS

We conducted a cross-sectional study investigating the relationship between region of ancestry (East, Central, South or West Africa) and kidney disease in people of sub-Saharan African ancestry with HIV in the UK between May 2018 and February 2020. The primary outcome was renal impairment (estimated glomerular filtration rate [eGFR] of <60 mL/min/1.73 m2). Secondary outcomes were stage 5 CKD (eGFR <15 ml/min/1.73 m2, on dialysis for over 3 months or who had received a kidney transplant), proteinuria (urine protein/creatinine ratio >50 mg/mmol), and biopsy-confirmed HIV-associated nephropathy (HIVAN), focal segmental glomerulosclerosis (FSGS) or arterionephrosclerosis. Multivariable robust Poisson regression estimated the effect of region of African ancestry on kidney disease outcomes.

FINDINGS

Of the 2468 participants (mean age 48.1 [SD 9.8] years, 62% female), 193 had renal impairment, 87 stage 5 CKD, 126 proteinuria, and 43 HIVAN/FSGS or arterionephrosclerosis. After adjusting for demographic characteristics, HIV and several CKD risk factors and with East African ancestry as referent, West African ancestry was associated with renal impairment (prevalence ratio [PR] 2.06 [95% CI 1.40-3.04]) and stage 5 CKD (PR 2.23 [1.23-4.04]), but not with proteinuria (PR 1.27 [0.78-2.05]). West African ancestry (as compared to East/South African ancestry) was also strongly associated with a diagnosis of HIVAN/FSGS or arterionephrosclerosis on kidney biopsy (PR 6.44 [2.42-17.14]).

INTERPRETATION

Our results indicate that people of West African ancestry with HIV are at increased risk of kidney disease. Although we cannot rule out the possibility of residual confounding, geographical region of origin appears to be a strong independent risk factor for CKD as the association did not appear to be explained by several demographic, HIV or renal risk factors.

SARS-CoV-2 Infection and the Kidneys: An Evolving Picture

Since December 2019, a novel coronavirus known as Severe Acute Respiratory Virus 2 (SARS-CoV-2) has caused an outbreak of a respiratory illness worldwide. Even though SARS-CoV-2 primarily affects the respiratory system, other organs such as the heart and kidneys are implicated. The pathophysiology of Acute Kidney Injury (AKI) in coronavirus 2019 (COVID-19) patients is not clearly defined. Direct kidney injury results from virus entry through angiotensin-converting enzyme-2 (ACE2) receptors which are highly expressed by the podocytes and proximal convoluted tubules, as suggested by "viral-like" particles on electron microscopy. However, the link between the presence of viral particles in kidney tissue and kidney injury has not been fully explained. Furthermore, it is also hypothesized that collapsing focal segmental glomerulosclerosis (FSGS), myoglobin toxicity, sepsis-linked, and glomeruli fibrin thrombi is part of the mechanism for AKI. Reported cases link FSGS and high-risk apolipoprotein 1 (APOL1) alleles in patients of African ancestry. Typically, these patients present with AKI and nephrotic-range proteinuria. The rate of AKI in hospitalized patients is high and associated with a higher mortality rate in older patients with comorbidities. Even higher mortality is now being reported in patients with chronic kidney disease and kidney transplant recipients due to immune system dysfunction. Herein, we review the current literature on kidney disease and pathogenesis in COVID-19 patients.

Prognostic model for nephrotoxicity among HIV-positive Zambian adults receiving tenofovir disoproxil fumarate-based antiretroviral therapy

Persons living with HIV (PLWH) receiving tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART) risk suffering TDF-associated nephrotoxicity (TDFAN). TDFAN can result in short- and long-term morbidity, including permanent loss of kidney function, chronic kidney disease (CKD), and end-stage kidney disease (ESKD) requiring dialysis. Currently, there is no model to predict this risk or discern which patients to initiate TDF-based therapy. Consequently, some patients suffer TDFAN within the first few months of initiating therapy before switching to another suitable antiretroviral or a lower dose of TDF. In a prospective observational cohort study of adult Zambian PLWH, we modelled the risk for TDFAN before initiating therapy to identify individuals at high risk for experiencing AKI after initiating TDF-based therapy. We enrolled 205 HIV-positive, ART-naïve adults initiating TDF-based therapy followed for a median of 3.4 months for TDFAN at the Adult Infectious Disease Research Centre (AIDC) in Lusaka, Zambia. We defined TDFAN as meeting any of these acute kidney disease (AKD) criteria: 1) An episode of estimated glomerular filtration rate (eGFR)< 60ml/ min/1.73m2 within 3 months, 2) reduced eGFR by> 35% within 3 months or 3) increased serum creatinine by> 50% within 3 months. A total of 45 participants (22%) developed acute kidney disease (AKD) after TDF-based therapy. The development of AKD within the first 3 months of commencing TDF-based therapy was associated with an increase in baseline serum creatinine, age, baseline eGFR and female sex. We concluded that baseline characteristics and baseline renal function biomarkers predicted the risk for AKD within the first 3-months of TDF-based therapy.

Malaria-Associated Acute Kidney Injury in African Children: Prevalence, Pathophysiology, Impact, and Management Challenges

Acute kidney injury (AKI) is emerging as a complication of increasing clinical importance associated with substantial morbidity and mortality in African children with severe malaria. Using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria to define AKI, an estimated 24–59% of African children with severe malaria have AKI with most AKI community-acquired. AKI is a risk factor for mortality in pediatric severe malaria with a stepwise increase in mortality across AKI stages. AKI is also a risk factor for post-discharge mortality and is associated with increased long-term risk of neurocognitive impairment and behavioral problems in survivors. Following injury, the kidney undergoes a process of recovery and repair. AKI is an established risk factor for chronic kidney disease and hypertension in survivors and is associated with an increased risk of chronic kidney disease in severe malaria survivors. The magnitude of the risk and contribution of malaria-associated AKI to chronic kidney disease in malaria-endemic areas remains undetermined. Pathways associated with AKI pathogenesis in the context of pediatric severe malaria are not well understood, but there is emerging evidence that immune activation, endothelial dysfunction, and hemolysis-mediated oxidative stress all directly contribute to kidney injury. In this review, we outline the KDIGO bundle of care and highlight how this could be applied in the context of severe malaria to improve kidney perfusion, reduce AKI progression, and improve survival. With increased recognition that AKI in severe malaria is associated with substantial post-discharge morbidity and long-term risk of chronic kidney disease, there is a need to increase AKI recognition through enhanced access to creatinine-based and next-generation biomarker diagnostics. Long-term studies to assess severe malaria-associated AKI’s impact on long-term health in malaria-endemic areas are urgently needed.

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.

Diagnostic accuracy of semiquantitative point of care urine albumin to creatinine ratio and urine dipstick analysis in a primary care resource limited setting in South Africa

Background

The prevalence of chronic kidney disease (CKD) is predicted to rise over the next few decades. In resource-limited settings access to central laboratory services is limited. Point-of-care (POC) urine dipstick testing offers the potential to detect markers of kidney damage (albuminuria) as well as markers of other disease processes. We evaluated the diagnostic accuracy of the semi-quantitative albumin-creatinine ratio (ACR) Sysmex UC-1000 POC urine dipstick system as well as the extent of other abnormal dipstick findings in urine.

Methods

700 participants from a rural area in South Africa were screened for albuminuria. A spot urine sample was used to measure POC and central laboratory ACR. We determined the sensitivity, specificity, positive predictive value and negative predictive value of the POC ACR, and recorded dipstick parameters.

Results

The prevalence of albuminuria was 11.6% (95%CI; 9.3–14.2). Those with albuminuria had higher mean diastolic (82 vs 79 mmHg, p = 0.019) and systolic (133 vs 128 mmHg, p = 0.002) blood pressures and a higher proportion of diabetes mellitus (17.6 vs 4.9%, p < 0.001). The sensitivity of the POC ACR system was 0.79, specificity 0.84, positive predictive value 0.39 and negative predictive value 0.97. The sensitivity improved to 0.80, 0.85, 0.85 and 0.89 in those with elevated blood pressure, diabetes mellitus, HIV positive status, and those 65 years and older, respectively. Abnormalities other than albuminuria were detected in 240 (34.3%) of the samples; 88 (12.6%) were positive for haematuria, 113 (16.1%) for leucocytes, 66 (9.4%) for nitrites and 27 (3.9%) for glycosuria.

Conclusion

Our study shows that POC ACR has good negative predictive value and could be used to rule out albuminuria when screening for CKD. Additionally, a high proportion of participants had other urine abnormalities detected with dipsticks which may reflect kidney disease or co-morbid untreated genitourinary pathology such as urinary tract infections or endemic schistosomiasis with important implications for CKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02290-5.

Evaluating chronic kidney disease in rural South Africa: comparing estimated glomerular filtration rate using point-of-care creatinine to iohexol measured GFR

OBJECTIVES

The prevalence of chronic kidney disease is rising rapidly in low- and middle-income countries. Serum creatinine and estimation of glomerular filtration rate (GFR) are critical diagnostic tools, yet access to centralised laboratory services remains limited in primary care resource-limited settings. The aim of this study was to evaluate point-of-care (POC) technologies for serum creatinine measurement and to compare their performance to a gold standard measurement using iohexol measured GFR (mGFR).

METHODS

POC creatinine was measured using iSTAT^® and StatSensor^® devices in capillary and venous whole blood, and laboratory creatinine was measured using the compensated kinetic Jaffe method in 670 participants from a rural area in South Africa. GFR estimating equations Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease (CKD-EPI and MDRD) for POC and laboratory creatinine were compared to iohexol mGFR.

RESULTS

Calculated GFR for laboratory and POC creatinine measurements overestimated GFR (positive bias of 1.9-34.1 mL/min/1.73 m²). However, all POC devices had less positive bias than the laboratory Jaffe method (1.9-14.7 vs. 34.1 for MDRD, and 8.4-19.9 vs. 28.6 for CKD-EPI). Accuracy within 30% of mGFR ranged from 0.56 to 0.72 for POC devices and from 0.36 to 0.43 for the laboratory Jaffe method. POC devices showed wider imprecision with coefficients of variation ranging from 4.6 to 10.2% compared to 3.5% for the laboratory Jaffe method.

CONCLUSIONS

POC estimated GFR (eGFR) showed improved performance over laboratory Jaffe eGFR, however POC devices suffered from imprecision and large bias. The laboratory Jaffe method performed poorly, highlighting the need for laboratories to move to enzymatic methods to measure creatinine.

Cardiovascular Risk Factor Profiles and Disease in Black Compared to Other Africans with Chronic Kidney Disease

Methods

Cardiovascular risk factors, aortic and cardiac function, atherosclerosis extent, and cardiovascular event rates were assessed in 115 consecutive predialysis (n = 67) and dialysis patients (n = 48) including 46 black and 69 other (32 Asian, 28 white, and 9 mixed race) participants. Data were analysed in multivariable regression models.

Results

Overall, black compared to other African CKD patients had less frequent carotid artery plaque (OR (95% CI) = 0.38 (0.16–0.91)) despite an increased cardiovascular risk factor burden. In receiver operator characteristic curve analysis, the Framingham score performed well in identifying non-black but not black CKD patients with carotid plaque (area under the curve (AUC) (95% CI) = 0.818 (0.714–0.921) and AUC (95% CI) = 0.556 (0.375–0.921), respectively). Black compared to other African predialysis patients experienced larger Framingham scores and more adverse nontraditional cardiovascular risk factors, impaired arterial and diastolic function but similar cardiovascular event rates (OR (95% CI) = 0.93 (0.22 to 3.87)). Among dialysis patients, black compared to other Africans had an overall similar traditional and nontraditional cardiovascular risk factor burden, similar arterial and diastolic function but increased systolic function (partial R = 0.356, p = 0.01 and partial R = 0.315, p = 0.03 for ejection fraction and stroke volume, respectively) and reduced cardiovascular event rates (OR (95% CI) = 0.22 (0.05 to 0.88)).

Conclusion

Black compared to other African CKD patients have less frequent very high risk atherosclerosis and experience weaker cardiovascular risk factor-atherosclerotic CVD relationships. These disparities may be due to differences in epidemiological health transition stages. Among dialysis patients, black compared to other Africans have less cardiovascular events, which may represent a selection bias as previously documented in black Americans.

COVID-19-Related Laboratory Analyte Changes and the Relationship Between SARS-CoV-2 and HIV, TB, and HbA1c in South Africa

We conducted a retrospective analysis on data of all adults tested for SARS-CoV-2 across our laboratory network in South Africa over a 4-month period. Out of 842,197 tests, 11.7% were positive and 88.3% negative. The prevalence of HIV was 6.25 and 6.31% in the SARS-CoV-2-positive and SARS-CoV-2-negative cohort, respectively (p = 0.444). However, the prevalence of HIV-positive individuals in the critical cohort (9.15%) was higher than in the noncritical group (6.24%) (p = 0.011). Active tuberculosis infection was approximately 50% less in SARS-CoV-2-positive than in SARS-CoV-2-negative individuals. The prevalence of uncontrolled diabetes was 3.4 times higher in SARS-CoV-2-positive cases but was not higher in the critical vs. noncritical cases (p = 0.612). The neutrophil-to-lymphocyte ratio, coagulation markers, urea, and cardiac- and liver-related analytes were significantly elevated in the critical compared to noncritical cases. Platelet count and creatinine concentration did not differ significantly between the two groups. These findings do not support increased prevalence of HIV or tuberculosis in individuals with SARS-CoV-2 infection but do suggest an association of increased disease severity with HIV-positive status. Uncontrolled diabetes was positively associated with a significantly higher prevalence of SARS-CoV-2, and our investigation into analyte changes associated with SARS-CoV-2 disease severity supported previous findings of raised inflammatory markers, coagulation markers, liver- and cardiac-related analytes, and urea but not for creatinine and platelet count.

COVID-19 and Vulnerable Populations in Sub-Saharan Africa

The novel corona virus 2019 (COVID-19) outbreak which started in Hubei province in China has now spread to every corner of the earth. While the pandemic started later in Africa, it is now found in all African countries to varying degrees. It is thought that the prevalence and severity of disease is influenced by a number of non-communicable diseases (NCDs) which are all becoming increasingly prevalent in sub-Saharan Africa (SSA). In addition, SSA bears the major burden of human immunodeficiency virus (HIV) and tuberculosis (TB) infections. While data from Europe and the United States show that children are spared severe disease, it is uncertain if the same holds true in SSA where children suffer from sickle cell disease and malnutrition in addition to other infectious diseases. There is limited data from Africa on the effects of these conditions on COVID-19. In this review, we discuss the epidemiology of some of these conditions in Africa and the possible pathogenesis for the interactions of these with COVID-19.

An updated systematic review on the association between Cd exposure, blood pressure and hypertension

BACKGROUND

Since the first report by Perry et al. (1955), most studies affirmed the hypertensive effects of cadmium (Cd) in humans. Nonetheless, conclusions between studies remain inconsistent.

OBJECTIVE

The aim of this study was to reevaluate the evidence for a potential relationship between Cd exposure and altered blood pressure and/or hypertension, focusing on studies published between January 2010 and March 2020.

METHODS

We reviewed all observational studies from database searches (PubMed and SCOPUS) on Cd exposure and blood pressure or hypertension. We extracted information from studies that provided sufficient data on population characteristics, smoking status, exposure, outcomes, and design.

RESULTS

Thirty-eight studies met our inclusion criteria; of those, twenty-nine were cross sectional, three case control, five cohort and one interventional study. Blood or urinary Cd levels were the most commonly used biomarkers.

CONCLUSIONS

A positive association between blood Cd levels and blood pressure and/or hypertension was identified in numerous studies at different settings. Limited number of representative population-based studies of never-smokers was observed, which may have confounded our conclusions. The association between urinary Cd and blood pressure and/or hypertension remains uncertain due to conflicting results, including inverse relationships with lack of strong mechanistic support. We point to the urgent need for additional longitudinal studies to confirm our findings.

Health-related quality of life, palliative care needs and 12-month survival among patients with end stage renal disease in Uganda: protocol for a mixed methods longitudinal study

BACKGROUND

The prevalence of chronic kidney disease is on the rise globally and in sub-Saharan Africa. Due to its "silent" nature, many patients often present with advanced disease. At this point options for care are often limited to renal replacement therapies such as hemodialysis and kidney transplantation. In resource limited settings, these options are associated with catastrophic expenditures and increased household poverty levels. Early palliative care interventions, if shown to ensure comparable quality of life (QoL), can significantly mitigate this by focusing care on comfort, symptom control and QoL rather than primarily on prolonging survival.

METHODS

A mixed methods longitudinal study, recruiting patients with End Stage Renal Disease (ESRD) on hemodialysis or conservative management and following them up over 12 months. The study aims are to: 1) measure and compare the health-related quality of life (HRQoL) scores of patients with ESRD receiving hemodialysis with those receiving conservative management, 2) measure and compare the palliative care needs and outcomes of patients in the two groups, 3) explore the impact of treatment modality and demographic, socio-economic and financial factors on QoL and palliative care needs and outcomes, 4) review patient survival over 12 months and 5) explore the patients' lived experiences. The Kidney Disease Quality Of Life Short Form version 1.3 (KDQOL-SF) will be used to measure HRQoL; the African Palliative Care Association Palliative care Outcome Score (APCA POS) and the Palliative care Outcome Score for renal symptoms (POS-S Renal) will be used to assess palliative care needs and outcomes; and semi-structured in-depth interviews to explore the patients' experiences of living with ESRD. Data collection will be carried out at 0, 3, 6, 9 and 12 months.

DISCUSSION

To the best of our knowledge, no similar study has been conducted in sub-Saharan Africa. This will be an important step towards raising awareness of patients' need and preferences and the strengths and limitations of available health care services for ESRD in resource limited settings.

Methods to estimate baseline creatinine and define acute kidney injury in lean Ugandan children with severe malaria: a prospective cohort study

BACKGROUND

Acute kidney injury (AKI) is increasingly recognized as a consequential clinical complication in children with severe malaria. However, approaches to estimate baseline creatinine (bSCr) are not standardized in this unique patient population. Prior to wide-spread utilization, bSCr estimation methods need to be evaluated in many populations, particularly in children from low-income countries.

METHODS

We evaluated six methods to estimate bSCr in Ugandan children aged 6 months to 12 years of age in two cohorts of children with severe malaria (n = 1078) and healthy community children (n = 289). Using isotope dilution mass spectrometry (IDMS)-traceable creatinine measures from community children, we evaluated the bias, accuracy and precision of estimating bSCr using height-dependent and height-independent estimated glomerular filtration (eGFR) equations to back-calculate bSCr or estimating bSCr directly using published or population-specific norms.

RESULTS

We compared methods to estimate bSCr in healthy community children against the IDMS-traceable SCr measure. The Pottel-age based equation, assuming a normal GFR of 120 mL/min per 1.73m², was the more accurate method with minimal bias when compared to the Schwartz height-based equation. Using the different bSCr estimates, we demonstrated the prevalence of KDIGO-defined AKI in children with severe malaria ranged from 15.6-43.4%. The lowest estimate was derived using population upper levels of normal and the highest estimate was derived using the mean GFR of the community children (137 mL/min per 1.73m²) to back-calculate the bSCr. Irrespective of approach, AKI was strongly associated with mortality with a step-wise increase in mortality across AKI stages (p < 0.0001 for all). AKI defined using the Pottel-age based equation to estimate bSCr showed the strongest relationship with mortality with a risk ratio of 5.13 (95% CI 3.03-8.68) adjusting for child age and sex.

CONCLUSIONS

We recommend using height-independent age-based approaches to estimate bSCr in hospitalized children in sub-Saharan Africa due to challenges in accurate height measurements and undernutrition which may impact bSCr estimates. In this population the Pottel-age based GFR estimating equation obtained comparable bSCr estimates to population-based estimates in healthy children.

Chronic kidney disease in Cameroon: a scoping review

OBJECTIVES

This scoping review sought to summarize available data on the prevalence, associated factors, etiology, comorbidities, treatment, cost and mortality of chronic kidney disease (CKD) in Cameroon.

METHODS

We searched PubMed, Scopus and African Journals Online from database inception to 31 March, 2020 to identify all studies published on the prevalence, associated factors, etiology, comorbidities, treatment, cost and mortality of CKD in Cameroon.

RESULTS

Thirty studies were included. The prevalence of CKD varied from 3 to 14.1 and 10.0%-14.2% in rural and urban areas, respectively. The prevalence of CKD in patients with hypertension, diabetes mellitus, and human immunodeficiency virus was 12.4-50.0, 18.5%, and 3.0-47.2%, respectively. Hypertension (22.3-59.1%), chronic glomerulonephritis (15.8-56.2%), and diabetes mellitus (15.8-56.2%) were the most common causes of CKD. The cause was unknown in 13.5-17.0% of the cases. Advanced age, hypertension, diabetes mellitus, and obesity were frequent associated factors. Hemodialysis was the main treatment modality in patients with End Stage Renal Disease (ESRD). The monthly cost of management of non-dialyzed CKD was 163 US dollars. The one-year mortality rate of ESRD was 26.8-38.6%.

CONCLUSION

Chronic kidney disease affects about one in 10 adults in the general population in Cameroon. Patients with hypertension, diabetes mellitus, and human immunodeficiency virus bear the greatest burden of CKD in Cameroon. Advanced age, hypertension, diabetes mellitus, and obesity are major factors associated with CKD. Chronic kidney disease in Cameroon is associated with high morbidity and mortality and huge economic cost on the patient.

Evaluation of medication adherence and predictors of sub-optimal adherence among pre-dialysis patients with chronic kidney disease

Background:

Multiple medications are required to effectively manage chronic kidney disease (CKD) and associated complications, posing the risk of poor medication adherence.

Objectives:

To measure medication adherence levels and to investigate the potential predictors of sub-optimal medication adherence in pre-dialysis patients with CKD.

Methods:

A prospective study was conducted in the medical and nephrology outpatients’ clinics in Maiduguri. Non-dialysis patients with CKD stages 1–4 aged 18 years and above were recruited through their physicians. The level of medication adherence was determined using Morisky Medication Adherence Scale. Descriptive statistics were used to summarize patients’ background characteristics. Multivariate binary logistic regression analyses were performed to investigate the significantly potential predictors of sub-optimal medication adherence at a p < 0.05.

Results:

There were 107 participants (48.6%) who had high medication adherence, while 97 (44.1%), and 16 (7.3%) of them had moderate adherence, and low adherence, respectively. The univariate analysis revealed that medication adherence level differed significantly with the number of medications taken daily by patients (p < 0.05). Multivariate logistic regression analyses did not reveal a significant independent predictor of sub-optimal medication adherence.

Conclusion:

A majority of the participants reported sub-optimal medication adherence. The independent variables considered did not significantly predict sub-optimal medication adherence in the study population. Nevertheless, the study findings highlight the importance of clinical pharmacists’ CKD management supportive care to help improve medication adherence.

Identify the Risk Factors of COVID-19-Related Acute Kidney Injury: A Single-Center, Retrospective Cohort Study

Background: The kidney is a target organ that could be infected by SARS-CoV-2, and acute kidney injury (AKI) was associated with a higher risk of COVID-19 patients' in-hospital death. However, no published works discussed about the risk factors of COVID-19 related AKI. Methods: We conducted a retrospective cohort study, recruiting COVID-19 inpatients from the Sino-French branch of Tongji Hospital. Demographic, clinical, treatment, and laboratory data were collected and compared. We used univariable and multivariable logistic regression methods to identify the risk factors of COVID-19-related AKI. Results: Of the 116 patients in our study, 12 (10.3%) were recognized as AKI, including 5 (4.3%) in-hospital AKI. Multivariable regression showed increasing odds of COVID-19-related AKI associated with COVID-19 clinical classification (OR = 8.155, 95% CI = 1.848-35.983, ref = non-critical, p = 0.06), procalcitonin more than 0.1 ng/mL (OR = 4.822, 95% CI = 1.095-21.228, p = 0.037), and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 (OR = 13.451, 95% CI = 1.617-111.891, p = 0.016). Conclusions: COVID-19-related AKI was likely to be related to multiorgan failure rather than the kidney tropism of SARS-CoV-2. The potential risk factors of COVID-19 clinical classification, procalcitonin more than 0.1 ng/mL, and eGFR <60 mL/min/1.73 m2 could help clinicians to identify patients with kidney injury at an early stage.