Screening for proteinuria and chronic kidney disease risk factors in Kinshasa: a World Kidney Day 2007 study

Cost-effectiveness of screening for chronic kidney disease in the general adult population: a systematic review

Introduction

Chronic kidney disease (CKD) is a significant public health problem, with rising incidence and prevalence worldwide, and is associated with increased morbidity and mortality. Early identification and treatment of CKD can slow its progression and prevent complications, but it is not clear whether CKD screening is cost-effective. The aim of this study is to conduct a systematic review of the cost-effectiveness of CKD screening strategies in general adult populations worldwide, and to identify factors, settings and drivers of cost-effectiveness in CKD screening.

Methods

Studies examining the cost-effectiveness of CKD screening in the general adult population were identified by systematic literature search on electronic databases (MEDLINE OVID, Embase, Cochrane Library and Web of Science) for peer-reviewed publications, hand-searched reference lists and grey literature of relevant sites, focusing on the following themes: (i) CKD, (ii) screening and (iii) cost-effectiveness. Studies comprising health economic evaluations performed for CKD screening strategies, compared with no CKD screening or usual-care strategy in adult individuals, were included. Study characteristics, model assumptions and CKD screening strategies of selected studies were identified. The primary outcome of interest is the incremental cost-effectiveness ratio (ICER) of CKD screening, in cost per quality-adjusted life year (QALY) and life-year gained (LYG), expressed in 2022 US dollars equivalent.

Results

Twenty-one studies were identified, examining CKD screening in general and targeted populations. The cost-effectiveness of screening for CKD was found to vary widely across different studies, with ICERs ranging from $113 to $430 595, with a median of $26 662 per QALY and from $6516 to $38 372, with a median of $29 112 per LYG. Based on the pre-defined cost-effectiveness threshold of $50 000 per QALY, the majority of the studies found CKD screening to be cost-effective. CKD screening was especially cost-effective in those with diabetes ($113 to $42 359, with a median of $27 471 per QALY) and ethnic groups identified to be higher risk of CKD development or progression ($23 902 per QALY in African American adults and $21 285 per QALY in Canadian indigenous adults), as indicated by a lower ICER. Additionally, the cost-effectiveness of CKD screening improved if it was performed in older adults, populations with higher CKD risk scores, or when setting a higher albuminuria detection threshold or increasing the interval between screening. In contrast, CKD screening was not cost-effective in populations without diabetes and hypertension (ICERs range from $117 769 to $1792 142, with a median of $202 761 per QALY). Treatment effectiveness, prevalence of CKD, cost of CKD treatment and discount rate were identified to be the most common influential drivers of the ICERs.

Conclusions

Screening for CKD is especially cost-effective in patients with diabetes and high-risk ethnic groups, but not in populations without diabetes and hypertension. Increasing the age of screening, screening interval or albuminuria detection threshold, or selection of population based on CKD risk scores, may increase cost-effectiveness of CKD screening, while treatment effectiveness, prevalence of CKD, cost of CKD treatment and discount rate were influential drivers of the cost-effectiveness.

Use of Medicinal Plants in Africa: A Case Study From the Democratic Republic of Congo (DRC)

Although medicinal plants are beneficial, they also can be important risk factors for the development of acute and chronic kidney injury, as well toxicity of other solid organs. There are a lack of reports of adverse kidney events and drug interactions resulting from medicinal plants owing to a lack of professional surveillance and specific data on kidney toxicity, especially in low-resource settings. Within the context of increased medicinal plant use and lack of effective regulatory control, safety is a key priority issue. We review the benefits and adverse effects of medicinal plants with particular reference to nephrotoxicity encountered in the Democratic Republic of Congo in sub-Saharan Africa.

Early Identification of Chronic Kidney Disease – A Scoping Review of the Global Populations

Introduction

Decisions on whether to screen for chronic kidney disease (CKD) or not remain contentious in nephrology. This study provides a global overview of early CKD identification efforts.

Methods

Guidelines for scoping reviews were followed and studies were identified by searching MEDLINE, EMBASE, Cochrane Library, CINAHL, ISI Web of Science, and PsycINFO. Data extracted from included studies focused on the following 4 themes: study population, measurement methods, interventions used, and available policies.

Results

We identified 290 CKD screening and detection programs from 83 countries. Overall sample size was 3.72 million (North East Asia: 1.19 million), detection of CKD was the aim in 97.6%, 63.1% used population-based screening methods, and only 12.4% were in rural populations. Reported CKD prevalence (stages 3–5) was higher in targeted- (14.8%) than population-based studies (8.0%). Number of persons needed to screen (NNS) to identify 1 case was also lower in targeted studies (7 vs. 13). Single measurements (80%) and the combination of estimation of glomerular filtration rate with a urine test (albuminuria/proteinuria) (71.4%) were frequently used to detect CKD. Only 2.8% of studies included an intervention such as pharmacotherapy in identified cases. Policies on early identification were available in 30.1% of countries included.

Conclusion

Methods for early CKD identification vary worldwide, often leading to wide variations in the reported prevalence. Efforts to standardize measurement methods for early detection focusing on high-risk populations and ensuring appropriate interventions are available to those identified with CKD will improve the value of programs and improve patient outcomes.

Obesity and CKD in Sub-Saharan Africa: A Narrative Review

Obesity is a major public health problem in the developed world, where it has reached an epidemic status over the last few decades. In parallel with this, the prevalence of chronic kidney disease (CKD) has increased. Although obesity is a risk factor for hypertension and diabetes, it is also independently associated with the development and progression of CKD. Two-third of patients with CKD worldwide will be residents of developing countries by the year 2030. Risk factors for CKD are prevalent in the sub-Saharan Africa region; this review discusses the available data regarding the relationship between obesity and CKD. The prevalence of CKD appears to correlate with increasing adiposity in sub-Saharan Africa; however, limited data are currently available, and the analysis of this association is further complicated by a variety of parameters used to define obesity. (eg, body mass index vs waist circumference). Longer, large-scale studies are needed to inform the prevalence and kidney implications of obesity in sub-Saharan Africa.

Current Management Strategies of Chronic Kidney Disease in Resource-Limited Countries

The incidence and prevalence of chronic kidney disease (CKD) and kidney failure continues to increase worldwide, especially in resource-limited countries. Many countries in this category already have a massive burden of communicable diseases, as well as socio-economic and socio-demographic challenges. The rising CKD burden and exorbitant economic cost associated with treatment are mainly responsible for the alarming mortality rate associated with kidney disease in these regions. There is often poor risk factor (diabetes and hypertension) and CKD awareness in these countries and limited availability and affordability of treatment options. Given these observations, early disease detection and preventive measures remain the best options for disease management in resource-limited settings. Primary, secondary and tertiary preventive strategies need to be enhanced and should particularly include measures to increase awareness, regular assessment to detect hypertension, diabetes and albuminuria, options for early referral of identified patients to a nephrologist and options for conservative kidney management where kidney replacement therapies may not be available or indicated. Much is still needed to be done by governments in these regions, especially regarding healthcare funding, improving the primary healthcare systems and enhancing non-communicable disease detection and treatment programs as these will have effects on kidney care in these regions.

CKD and Pregnancy Outcomes in Africa: A Narrative Review

Chronic kidney disease (CKD) is associated with adverse maternal and fetal outcomes and is reported to affect up to 3% of women of reproductive age in high-income countries, but estimated prevalence may be as much as 50% higher in low and middle-income countries (LMICs). All pregnancy complications occur much more frequently in women in LMICs compared with those in high-income countries. Given the anticipated high prevalence of CKD in women of reproductive age and high rates of maternal and fetal adverse events in Africa, we sought to explore the association between CKD and pregnancy outcomes in this setting through a narrative review of the literature. This review demonstrates the paucity of data in this area and highlights the systemic barriers that exist in many African countries that prevent robust management of noncommunicable diseases such as CKD during a woman's reproductive life. This evidence gap highlights the need for further research, starting by sampling normal ranges of serum creatinine concentrations in pregnant and nonpregnant women of reproductive age in the diverse populations of Africa, estimating prevalence of CKD, and understanding associated pregnancy outcomes. Research should then focus on pragmatic interventions that may improve outcomes for women and their infants.

Metabolic syndrome and its components are related to a higher risk for albuminuria and proteinuria: Evidence from a meta-analysis on 10,603,067 subjects from 57 studies

BACKGROUND & AIM

Previous studies have explored the relation of metabolic syndrome (MetS), its components and the risk of albuminuria/proteinuria but their results are inconsistent. Then, we aimed to conduct a meta-analysis in order to resolve these controversies.

METHOD

PubMed and Scopus were systematically searched from their inception to 1 march 2018. Risk estimates and their 95% confidence intervals were extracted and pooled using the random-effects approach.

RESULT

A total of 57 studies, 44 studies on albuminuria and 13 studies on proteinuria, with a total sample size of 10,603,067 participants, were included in this meta-analysis. Overall, MetS was contributed to higher risks of proteinuria (OR = 2.08, 95%CI = 1.85-2.34) and albuminuria (OR = 1.92, 95%CI = 1.71-2.15), independent of diabetes status; although, this relationship was more noticeable in studies that used the WHO definition of MetS and in non-East Asian populations. Also, the relationship between MetS and proteinuria was sex independent, while, for albuminuria was significant only in men. MetS components such as obesity, impaired fasting glucose, elevated blood pressure and hypertriglyceridemia were associated with significant increases in proteinuria and albuminuria risk, while lower HDL-Cholesterol was only linked to greater risk of proteinuria. Moreover, the total impact of MetS on proteinuria was more remarkable than each component of the syndrome and an escalating dose-response association was found between the number of MetS components and albuminuria risk.

CONCLUSION

MetS and its components are potential risk factors for albuminuria and proteinuria.

The epidemiology of chronic kidney disease and the association with non-communicable and communicable disorders in a population of sub-Saharan Africa

In sub-Saharan Africa (SSA), epidemiological data for chronic kidney disease (CKD) are scarce. We conducted a prospective cross-sectional study including 952 patients in an outpatient clinic in Tanzania to explore CKD prevalence estimates and the association with cardiovascular and infectious disorders. According to KDIGO, we measured albumin-to-creatinine ratio and calculated eGFR using CKD-EPI formula. Factors associated with CKD were calculated by logistic regression. Venn diagrams were modelled to visualize interaction between associated factors and CKD. Overall, the estimated CKD prevalence was 13.6% (95% CI 11-16%). Ninety-eight patients (11.2%) (95% CI 9-14%) were categorized as moderate, 12 (1.4%) (95% CI 0-4%) as high, and 9 (1%) (95% CI 0-3%) as very high risk according to KDIGO. History of tuberculosis (OR 3.75, 95% CI 1.66-8.18; p = 0.001) and schistosomiasis (OR 2.49, 95% CI 1.13-5.18; p = 0.02) were associated with CKD. A trend was seen for increasing systolic blood pressure (OR 1.02 per 1 mmHg, 95% CI 1.00-1.03; p = 0.01). Increasing BMI (OR 0.92 per 1kg/m2, 95% CI 0.88-0.96; p = <0.001) and haemoglobin (OR 0.82 per 1g/dL, 95% CI 0.72-0.94; p = 0.004) were associated with risk reduction. Diabetes was associated with albuminuria (OR 2.81, 95% CI 1.26-6.00; p = 0.009). In 85% of all CKD cases at least one of the four most common factors (hypertension, diabetes, anaemia, and history of tuberculosis or schistosomiasis) was associated with CKD. A singular associated factor was found in 61%, two in 14%, and ≥3 in 10% of all CKD cases. We observed a high prevalence estimate for CKD and found that both classical cardiovascular and neglected infectious diseases might be associated with CKD in a semi-rural population of SSA. Our finding provides further evidence for the hypothesis that the "double burden" of non-communicable and endemic infectious diseases might affect kidney health in SSA.

Prevalence and burden of chronic kidney disease among the general population and high-risk groups in Africa: a systematic review

OBJECTIVES

While increasing attention is paid to the rising prevalence of chronic diseases in Africa, there is little focus on chronic kidney disease (CKD). This systematic review assesses CKD burden among the general population and high-risk groups on the entire African continent.

DESIGN, SETTING AND PARTICIPANTS

We searched Medline and PubMed databases for articles published between 1 January 1995 and 7 April 2017 by sensitive search strategies focusing on CKD surveys at the community level and high-risk groups. In total, 7918 references were evaluated, of which 7766 articles were excluded because they did not meet the inclusion criteria. Thus, 152 studies were included in the final analysis.

OUTCOME MEASUREMENT

The prevalence of CKD in each study group was expressed as a range and pooled prevalence rate of CKD was calculated as a point estimate and 95% CI. No meta-analysis was done. Data were presented for different populations.

RESULTS

In the community-level studies, based on available medium-quality and high-quality studies, the prevalence of CKD ranged from 2% to 41% (pooled prevalence: 10.1%; 95% CI 9.8% to 10.5%). The prevalence of CKD in the high-risk groups ranged from 1% to 46% (pooled prevalence: 5.6%; 95% CI 5.4% to 5.8%) in patients with HIV (based on available medium-quality and high-quality studies), 11%-90% (pooled prevalence: 24.7%; 95% CI 23.6% to 25.7%) in patients with diabetes (based on all available studies which are of low quality except four of medium quality) and 13%-51% (pooled prevalence: 34.5%; 95 % CI 34.04% to 36%) in patients with hypertension (based on all available studies which are of low quality except two of medium quality).

CONCLUSION

In Africa, CKD is a public health problem, mainly attributed to high-risk conditions as hypertension and diabetes. The poor data quality restricts the validity of the findings and draws the attention to the importance of designing future robust studies.

Epidemiology of chronic kidney disease: think (at least) twice!

The introduction of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines has substantially contributed to the early detection of different stages of chronic kidney disease (CKD). Several recent studies from different parts of the world mention a CKD prevalence of between 8 and 13%. There are several reasons the CKD prevalence found in a study of a particular population is clearly overestimated. The structure of the population pyramid (young or older age) of the study sample may result in high or low CKD prevalence. The absence of using an isotope dilution mass spectrometry creatinine assay can be the source of high bias in CKD prevalence. In addition, using an arbitrary single threshold of estimated glomerular filtration rate (eGFR; <60 mL/min/1.73 m2) for classifying CKD leads to a substantial 'overdiagnosis' (false positives) in the elderly (>65 years of age), particularly in those without albuminuria (or proteinuria), haematuria or hypertension. It also results in a significant 'underdiagnosis' (false negatives) in younger individuals with an eGFR >60 mL/min/1.73 m2 and below the third percentile for their age/gender category. The use of third percentile eGFR rates as a cut-off based on age/gender-specific reference values of eGFR allows the detection of these false positives and negatives. In the present article, we focus on an important and frequently omitted criterion in epidemiological studies: chronicity. Indeed, the two most important factors introducing a high number (up to 50%) of false positives are lack of confirming proteinuria and the absence of proof of chronicity of the eGFR found at first screening. There is an urgent need for quality studies of the prevalence of CKD using representative randomized samples of the population, applying the KDIGO guidelines correctly.

Chronic kidney disease in low- and middle-income countries

Most of the global burden of chronic kidney disease (CKD) is occurring in low- and middle-income countries (LMICs). As a result of rapid urbanization in LMICs, a growing number of populations are exposed to numerous environmental toxins, high infectious disease burdens and increasing rates of noncommunicable diseases. For CKD, this portends a high prevalence related to numerous etiologies, and it presents unique challenges. A better understanding of the epidemiology of CKD in LMICs is urgently needed, but this must be coupled with strong public advocacy and broad, collaborative public health efforts that address environmental, communicable, and non-communicable risk factors.

Prevalence and determinants of chronic kidney disease in rural and urban Cameroonians: a cross-sectional study

Background

Chronic kidney disease (CKD) is a global public health problem that disproportionally affects people of African ethnicity. We assessed the prevalence and determinants of CKD and albuminuria in urban and rural adults Cameroonians.

Methods

This was a cross-sectional study of 6-month duration (February to July 2014), conducted in the health district of Dschang (Western Region of Cameroon), using a multistage cluster sampling. All adults diagnosed with albuminuria (≥30 mg/g) and/or decreased estimated glomerular filtration rate (eGFR) (<60 ml/min/1.73 m²) were re-examined three months later. Logistic regression models were used to relate baseline characteristics with prevalent CKD.

Results

We included 439 participants with a mean age of 47 ± 16.1 years; with 185 (42.1 %) being men and 119 (27.1 %) being urban dwellers. There was a high prevalence of hypertension (25.5 %), diabetes (9.8 %), smoking (9.3 %), alcohol consumption (59.7 %), longstanding use of herbal medicine (90.9 %) and street medications (87.5 %), and overweight/obesity (53.3 %) which were predominant in rural area. The prevalence of CKD was 13.2 % overall, 14.1 % in rural and 10.9 % in urban participants. Equivalents figures for CKD stages G3-G4 and albuminuria were 2.5 %, 1.6 % and 5.0 %; and 12.1 %, 14.1 % and 6.7 % respectively. Existing hypertension and diabetes were associated with all outcomes. Elevated systolic blood pressure and the presence of hypertension and diabetes were the predictors of albuminuria and CKD while urban residence was associated with CKD stages G3-G4.

Conclusion

The prevalence of CKD and albuminuria was high in this population, predominantly in rural area, and driven mostly by the commonest risk factors.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0111-8) contains supplementary material, which is available to authorized users.

Prevalence and risk factors of chronic kidney disease in urban adult Cameroonians according to three common estimators of the glomerular filtration rate: a cross-sectional study

Background

Chronic kidney disease (CKD) is a major threat to the health of people of African ancestry. We assessed the prevalence and risk factors of CKD among adults in urban Cameroon.

Methods

This was a cross-sectional study of two months duration (March to April 2013) conducted at the Cité des Palmiers health district in the Littoral region of Cameroon. A multistage cluster sampling approach was applied. Estimated glomerular filtration rate (eGFR) was based on the Cockcroft-Gault (CG), the four-variable Modification of Diet in Renal Disease (MDRD) study and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Logistic regression models were used to investigate the predictors of CKD.

Results

In the 500 participants with a mean age of 45.3 ± 13.2 years included, we observed a high prevalence of overweight and obesity (60.4 %), hypertension (38.6 %) and diabetes (2.8 %). The mean eGFR was 93.7 ± 24.9, 97.8 ± 24.9 and 99.2 ± 31.4 ml/min respectively with the MDRD, CG and CKD-EPI equations. The prevalence of albuminuria was 7.2 % while the prevalence of decreased GFR (eGFR < 60 ml/min) and CKD (any albuminuria and/or eGFR < 60 ml/min) was 4.4 and 11 % with MDRD, 5.4 and 14.2 % with CG, and 8.8 and 10 % with CKD-EPI. In age and sex adjusted logistic regression models, advanced age, known hypertension and diabetes mellitus, increasing body mass index and overweight/obesity were the predictors of albuminuria, decreased GFR and CKD according to various estimators.

Conclusion

There is a high prevalence of CKD in urban adults Cameroonian, driven essentially by the commonest risk factors for CKD.

Sickle cell trait is not associated with chronic kidney disease in adult Congolese patients: a clinic-based, cross-sectional study

OBJECTIVE

The aim of this study was to evaluate the determinants of chronic kidney disease (CKD) with special emphasis on sickle cell trait (SCT).

METHODS

Three hundred and fifty-nine patients (171 men and 188 women), aged 18 years or older, with reduced kidney function (eGFR < 90 ml/min/1.73 m(2)) and seen at secondary and tertiary healthcare in Kinshasa were consecutively recruited in this cross-sectional study. Serum creatinine and haemoglobin electrophoresis were performed in each patient. CKD was defined as < 60 ml/min/1.73 m(2). Logistic regression analysis was used to assess determinants of CKD with a special emphasis on SCT. A p-value < 0.05 defined the level of statistical significance.

RESULTS

SCT was present in 19% of the study population; its frequency was 21 and 18% (p > 0.05) in patients with and without CKD, respectively. In multivariate analysis, sickle cell trait was not significantly (OR: 0.38; 95% CI: 0.559-1.839; p = 0.235) associated with CKD; the main determinants were dipstick proteinuria (OR: 1.86; 95% CI: 1.094-3.168; p = 0.02), the metabolic syndrome (OR: 1.69; 95% CI: 1.033-2.965; p = 0.03), haemoblobin ≥ 12 g/dl (OR: 0.36; 95% CI: 0.210-0.625; p = 0.001), and personal history of hypertension (OR: 2.16; 95% CI: 1.202-3.892; p = 0.01) and of diabetes mellitus (OR: 2.35; 95% CI: 1.150-4.454; p = 0.001).

CONCLUSION

SCT was not an independent determinant of CKD in the present case series. Traditional risk factors emerged as the main determinants of CKD.

The epidemiology of chronic kidney disease in Northern Tanzania: a population-based survey

BACKGROUND

In sub-Saharan Africa, kidney failure has a high morbidity and mortality. Despite this, population-based estimates of prevalence, potential etiologies, and awareness are not available.

METHODS

Between January and June 2014, we conducted a household survey of randomly-selected adults in Northern Tanzania. To estimate prevalence we screened for CKD, which was defined as an estimated glomerular filtration rate ≤ 60 ml/min/1.73m2 and/or persistent albuminuria. We also screened for human immunodeficiency virus (HIV), diabetes, hypertension, obesity, and lifestyle practices including alcohol, tobacco, and traditional medicine use. Awareness was defined as a self-reported disease history and subsequently testing positive. We used population-based age- and gender-weights in estimating prevalence, and we used generalized linear models to explore potential risk factors associated with CKD, including living in an urban environment.

RESULTS

We enrolled 481 adults from 346 households with a median age of 45 years. The community-based prevalence of CKD was 7.0% (95% CI 3.8-12.3), and awareness was low at 10.5% (4.7-22.0). The urban prevalence of CKD was 15.2% (9.6-23.3) while the rural prevalence was 2.0% (0.5-6.9). Half of the cases of CKD (49.1%) were not associated with any of the measured risk factors of hypertension, diabetes, or HIV. Living in an urban environment had the strongest crude (5.40; 95% CI 2.05-14.2) and adjusted prevalence risk ratio (4.80; 1.70-13.6) for CKD, and the majority (79%) of this increased risk was not explained by demographics, traditional medicine use, socioeconomic status, or co-morbid non-communicable diseases (NCDs).

CONCLUSIONS

We observed a high burden of CKD in Northern Tanzania that was associated with low awareness. Although demographic, lifestyle practices including traditional medicine use, socioeconomic factors, and NCDs accounted for some of the excess CKD risk observed with urban residence, much of the increased urban prevalence remained unexplained and will further study as demographic shifts reshape sub-Saharan Africa.

The epidemiology of chronic kidney disease in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Amid rapid urbanisation, the HIV epidemic, and increasing rates of non-communicable diseases, people in sub-Saharan Africa are especially vulnerable to kidney disease. Little is known about the epidemiology of chronic kidney disease (CKD) in sub-Saharan Africa, so we did a systematic review and meta-analysis examining the epidemiology of the disease.

METHODS

We searched Medline, Embase, and WHO Global Health Library databases for all articles published through March 29, 2012, and searched the reference lists of retrieved articles. We independently reviewed each study for quality. We used the inverse-variance random-effects method for meta-analyses of the medium-quality and high-quality data and explored heterogeneity by comparing CKD burdens across countries, settings (urban or rural), comorbid disorders (hypertension, diabetes, HIV), CKD definitions, and time.

FINDINGS

Overall, we included 90 studies from 96 sites in the review. Study quality was low, with only 18 (20%) medium-quality studies and three (3%) high-quality studies. We noted moderate heterogeneity between the medium-quality and high-quality studies (n=21; I(2)=47·11%, p<0·0009). Measurement of urine protein was the most common method of determining the presence of kidney disease (62 [69%] studies), but the Cockcroft-Gault formula (22 [24%] studies) and Modification of Diet in Renal Disease formula (17 [19%] studies) were also used. Most of the studies were done in urban settings (83 [93%] studies) and after the year 2000 (57 [63%] studies), and we detected no significant difference in the prevalence of CKD between urban (12·4%, 95% CI 11-14) and rural (16·5%, 13·8-19·6) settings (p=0·474). The overall prevalence of CKD from the 21 medium-quality and high-quality studies was 13·9% (95% CI 12·2-15·7).

INTERPRETATION

In sub-Saharan Africa, CKD is a substantial health burden with risk factors that include communicable and non-communicable diseases. However, poor data quality limits inferences and draws attention to the need for more information and validated measures of kidney function especially in the context of the growing burden of non-communicable diseases.

FUNDING

Duke University.

[Epidemiology of chronic kidney disease in the Democratic Republic of Congo: review of cross-sectional studies from Kinshasa, the capital]

Chronic kidney disease (CKD) is a worldwide public health problem. Little is known about its burden in Africa. This paper reviews the knowledge of CKD in Kinshasa, summarizing four studies undertaken in the general population and traditional health system of Kinshasa. CKD was defined by either kidney damage (proteinuria> or =300 mg/day) or reduced kidney function (eGFR<60 ml/min/1.73 m(2)). In the general population, the prevalence of CKD all stage is 12.4 %. Our work shows also the high prevalence of proteinuria among subjects who do not have diabetes or hypertension, the lack of early detection and management of CKD risk factors in the traditional health care system leading to late referral or premature deaths, and the limits of renal replacement treatment. CKD affects young people in the DRC, in contrast to the United States, where CKD is more prevalent in older people. Major determinants of CKD in our studies were hypertension, diabetes, overweight, age, lower socioeconomic status, and Human immunodeficiency virus (HIV) infection. Glomerular nephropathy (mainly focal segmental glomerulosclerosis) remains the leading cause of end stage renal disease. An annual screening of the population for proteinuria and CKD risk factors is feasible and will, it is hoped, provide the basis for building a nationwide prevention strategy.

High prevalence of undiagnosed chronic kidney disease among at-risk population in Kinshasa, the Democratic Republic of Congo

Background

There is limited knowledge of Chronic Kidney Disease (CKD) among high risk populations, especially in the developing countries. We report our study of testing for CKD in at-risk subjects.

Methods

In a cross-sectional study, 527 people from primary and secondary health care areas in the city of Kinshasa were studied from a random sample of at-risk out-patients with hypertension, diabetes, obesity, or HIV+. We measured blood pressure (BP), blood glucose level, proteinuria, body mass index, and estimated glomerular filtration rate (eGFR by MDRD equation) using calibrated creatinine levels based on one random measurement. The associations between health characteristics, indicators of kidney damage (proteinuria) and kidney function (<60 ml/min/1.73 m²) were also examined.

Results

The prevalence of CKD in this study was 36%, but only 12% were aware of their condition. 4% of patients had stage 1 CKD, 6% stage 2, 18% stage 3, 2% stage 4, and 6% had stage 5. 24 hour quantitative proteinuria (>300 mg/day) was found in 19%. In those with the at-risk conditions, the % of CKD was: 44% in patients with hypertension, 39% in those with diabetes; 16% in the obese and 12% in those who were HIV+. 82% of those with a history of diabetes had elevated serum glucose levels at screening (≥ 126 mg/dl). Only 6% of individuals with hypertension having CKD had reduced BP to lower than 130/80 mmHg. In multivariate analysis, diabetes, proteinuria and hypertension were the strongest determinants of CKD 3+.

Conclusion

It appears that one out of three people in this at-risk population has undiagnosed CKD and poorly controlled CKD risk factors. This growing problem poses clear challenges to this developing country. Therefore, CKD should be addressed through the development of multidisciplinary teams and improved communication between traditional health care givers and nephrology services. Attention to CKD risk factors must become a priority.