25 [OH] Vitamin D and Intact Parathyroid Hormone in Congolese Hemodialysis Patients: Evaluation of KDIGO Targets.

Background: Data on 25 [OH] vitamin D and intact parathyroid hormone [iPTH] in hemodialysis patients are very limited in sub-Saharan African countries. The present study aimed to assess the magnitude of hypovitaminosis D, and to evaluate the achievement of iPTH KDIGO 2017 targets among chronic hemodialysis patients followed in Kinshasa. Methods: We conducted a multicenter cross-sectional study in 6 hospitals in Kinshasa. All patients followed on hemodialysis for more than 3 months were included. Hypovitaminosis D was defined as <30 ng/mL (insufficiency = 20-29 ng/mL; deficiency if <20 ng/mL) and the targets for iPTH values were based on the 2017 KDIGO guidelines. The determinants for hypovitaminosis D were evaluated by logistic regression. Results: 251 patients [mean age 56 ± 14 years, 72.5% men, 63% hypertensive, 31% diabetic, 100% supplemented with native 25 [OH] vitamin D + CaCO3 were included. Hypovitaminosis D was found in 79.7% (deficiency 47.4%) and was associated with the male gender aOR 2.7 [1.4-5.2], p = 0.004, the low-permeability dialyzer 2.2 [1.1-4.2], p = 0.025 and anemia 3.9 [1.2-12.7], p = 0.022. Only 40% of patients with 25 [OH] vitamin D deficiency had iPTH according to KDIGO targets vs 6% of patients with severe hyperparathyroidism (iPTH > 600 pg/mL), 45% with levels between 16 and 150 pg/mL and 9% a iPTH ≤ 15 pg/mL. Conclusion: Despite a sunny environment, a large proportion of Congolese hemodialysis patients have hypovitaminosis D, in particular a deficiency. Among them, less than half have target iPTH values. These results show the benefit of regular monitoring of these parameters in order to optimize treatment.

Factors associated with acute kidney injury (AKI) and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit: a single-center prospective study.

INTRODUCTION: Acute kidney injury (AKI) is a complication of severe coronavirus disease 2019 (COVID-19). Kidney damage associated with COVID-19 could take specific features due to environmental and socio-cultural factors. This study evaluates the incidence of AKI, the associated factors, and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit. METHODS: In a prospective cohort study conducted in the intensive care unit (ICU) of the Centre Médical de Kinshasa (CMK), consecutive patients admitted for COVID-19 were screened for the presence of AKI between 27 March, 2020 and 27 January 2022. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines. The primary outcome was occurrence of AKI. The secondary outcome was 48 days' mortality and recovery of the renal function at intensive care unit (ICU) discharge. Survival (time-to death) curves were built using the Kaplan Meier methods. Multivariate analyses were performed by logistic regression to identify factors associated with AKI and Cox regression to explore the association between AKI and in-hospital mortality. The significance level of the p-value was set at 0.05. RESULTS: The median(IQR) sequential organ failure assessment score (SOFA) score and mean age of patients (215) including in our cohort were respectively 3(2-4) and 58.9 ± 14.9 years. The incidence of AKI was 28.4% with stages 1, 2, or 3 AKI accounted for 39.3%, 11.5%, and 49.2%, respectively. Hemodialysis was required in 16 out 215 (7.4%) patients. Dyspnea (adjusted odds ratio (aOR):2.27 [1.1--4.57] p = 0.021), SOFA ≥5 (aOR:3.11[1.29-7.53] p = 0.012), AST/ALT ratio (aOR: 1.53 [1.09-1.79] p = 0.015), N/L ratio (aOR:2.09 [1.09-3.20] p = 0.016), mechanical ventilation (aOR: 3.20 [1.66-10.51] p = 0.005) and Amikacin (aOR: 2.91 [1.37-6.18] p = 0.006) were the main factors associated with AKI. Patients with AKI had a mortality rate of 52.5% and 67.2% of the survivors did not recover kidney function at the end of hospitalization. Adjusted Cox regression analysis revealed that COVID-19-associated AKI was independently associated with in-hospital death (HR:2.96 [1.93-4.65] p = 0.013) compared to non-AKI patients. CONCLUSIONS: AKI was present in three out of ten COVID-19 patients. The most significant factors associated with AKI were dyspnea, SOFA ≥ 5, AST/ALT and N/L ratio, mechanical ventilation and Amikacin. AKI has been associated with an almost threefold increase in overall mortality and seven out of ten survivors did not recover kidney function after AKI.

Predictors of Mortality in Adults with Acute Kidney Injury Requiring Dialysis: A Cohort Analysis.

Introduction: Acute kidney injury (AKI) requiring renal replacement therapy is accompanied by considerable mortality. This present study evaluated predictors of mortality at initiation of hemodialysis (HD) in AKI patients in Goma (in the Democratic Republic of the Congo (DRC)). Methods: A single-centre cohort survey evaluated the clinical profile and survival rates of AKI patients admitted to HD in the only HD centre in Goma, North Kivu province (DRC). Data were collected from patients who underwent HD for AKI. Patient demographics, comorbidities, clinical presentation, laboratory tests, and mortality were reviewed and analyzed. The survival study used the Kaplan-Meier curve. Predictors of mortality were evaluated using Cox regression. Results: Of the 131 eligible patients, the mean age was 43.69 ± 16.56 years (range: 18-90 years). Men represented 54.96% of the cohort. The overall HD mortality rate was 25.19% (n = 33). In multivariate analysis, independent predictors of mortality in AKI stage 3 patients admitted to HD were as follows: age ≥ 60 years (adjusted hazard ratio (AHR) = 15.89; 95% CI: 3.98-63.40; p < 0.0001), traditional herbal medicine intake (AHR = 5.10; 95% CI: 2.10-12.38; p < 0.0001), HIV infection (AHR = 5.55; 95% CI: 1.48-20.73; p=0.011), anemia (AHR = 9.57; 95% CI: 2.08-43.87; p=0.004), hyperkalemia (AHR = 6.23; 95% CI: 1.26-30.72; p=0.025), respiratory distress (AHR = 4.66; 95% CI: 2.07-10.50; p < 0.0001), and coma (AHR = 11.39; 95% CI: 3.51-36.89; p < 0.0001). Conclusion: Initiation of hemodialysis with AKI has improved survival in patients with different complications.

Circulating Proprotein Convertase Subtilisin/Kexin type 9 level independently predicts incident cardiovascular events and all-cause mortality in hemodialysis black Africans patients.

BACKGROUND: Cardiovascular (CV) disease is the leading cause of mortality in patients with end-stage kidney disease (ESKD). The aim of the present study was to determine whether Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) could be an independent predictor of CV events and all-cause mortality in black African haemodialysis patients. METHODS: We carried out a prospective cohort study of all consecutive hemodialysis (HD) patients between August 2016 and July 2020, admitted in six hemodialysis centers of Kinshasa, Democratic Republic of Congo. Independent determinants of plasma PCSK-9 measured by ELISA were sought using multiple linear regression analysis. Kaplan-Meier's method described the incidence of CV events while competitive and proportional risk models looked for independent risk factors for death at the .05 significance level. RESULTS: Out of 207 HD patients, 91 (43.9%) died; 116 (56.1%) have survived. PCSK9 level was significantly higher in deceased patients compared to survivors: 28.0 (24.0-31.0) ng/l vs 9.6 (8.6-11.6) ng/ml (p <  0.001). Patients with plasma PCSK9 levels in tertile 3 had a higher incidence of CV events and mortality compared to patients with plasma PCSK9 levels in tertile 2 or tertile 1 (p <  0.001). Tertile 3 negatively influence survival rates (26.6%) compared to tertile 2 (54.7%) and tertile 1 (85.3%). Patients in tertile 3 and tertile 2 had a 4-fold higher risk of death than patients in tertile 1. After adjustment for all parameters, competitive risk analysis showed that mortality was 2 times higher in patients with stroke. Similarly, serum albumin < 3.5 g/dL or PCSK9 in tertile 3 were respectively associated with 2 or 6 times higher rates of deaths. CONCLUSION: Elevated plasma PCSK9 level is an independent major predictor of incident CV events and all-cause mortality in black African HD patients.

Circulating Proprotein Convertase Subtilisin/Kexin Type 9 Levels Predict Future Cardiovascular Event Risks in Hemodialyzed Black African Patients.

CONTEXT AND OBJECTIVE: Cardiovascular diseases are the leading cause of mortality in patients. In this context, proprotein convertase subtilisin/kexin type 9 (PCSK9) appears to be the new biomarker identified as interfering in lipid homeostasis. This study aimed to investigate the association between PCSK9, dyslipidemia, and future risk of cardiovascular events in a population of black Africans. METHODS: A cross-sectional study was conducted between August 2016 and July 2020 in six hemodialysis centers in the city of Kinshasa, Democratic Republic of the Congo. Serum PCSK9 was measured by ELISA; lipid levels of 251 chronic kidney disease grade 5 (CKD G5) hemodialysis patients and the Framingham predictive instrument were used for predicting cardiac events. RESULTS: Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and triglycerides (TG) were significantly increased in the tertile with the highest PCSK9. By contrast, high-density lipoprotein cholesterol (HDL-c) was significantly decreased in the same tertile. A strong positive and significant correlation was found between PCSK9 and TC, TG, and LDL-c. Negative and significant correlation was observed between PCSK9 and HDL-c. The levels of PCSK9, smoking, overweight, and atherogenic dyslipidemia were associated with future risks for cardiovascular events in univariate analysis. After adjustment, all these variables persisted as independent determinants of future risk for cardiovascular events. The probability of having a cardiovascular event in this population was independently associated with PCSK9 levels. Compared to the patients in the lowest PCSK9 tertile, patients with PCSK9 levels in the middle (aOR 5.9, 95% CI 2.06-17.3, P<0.001) and highest tertiles (aOR 8.9, 95% CI 3.02-25.08, P<0.001) presented a greater risk of cardiac event. CONCLUSION: Increased PCSK9 serum levels are associated with higher levels of TC, LDL-c, and TG and lower levels of HDL-c in black African hemodialysis patients. Serum PCSK9 levels in these patients predict increased risk of cardiovascular events, independent of traditional potential confounders.

Prognostic Significance of Abnormal Ankle-Brachial Index Among Long-term Hemodialysis Patients in Kinshasa, the Democratic Republic of the Congo.

OBJECTIVE: Early identification of atherosclerosis using a non-invasive tool like ankle-brachial index (ABI) could help reduce the risk for cardiovascular disease among long-term hemodialysis patients. The study objective was to assess the frequency and impact of abnormal ABI as a marker of subclinical peripheral artery disease (PAD) in chronic hemodialysis patients. METHODS: This was a historic cohort study of kidney failure patients on long-term hemodialysis for at least 6 months. The ABI, measured with two oscillometric blood pressure devices simultaneously, was used to assess subclinical atherosclerosis of low limb extremities. Abnormal ABI was defined as ABI <0.9 or >1.3 (PAD present). Survival was defined as time to death. Independent factors associated with abnormal ABI were assessed using multiple logistic regression analysis. Kaplan-Meier method (log-rank test) was used to compare cumulative survival between the two groups; a P value <0.05 was statistically significant. RESULTS: Abnormal ABI was noted in 50.6% (n=43) of the 85 kidney failure patients included in the study; 42.4% (n=36) had a low ABI, and 8.2% (n=7) had a high ABI. Factors associated with PAD present were cholesterol (adjusted odds ratio [AOR], 1.02; 95% confidence interval [CI], 1.01-1.04; P=0.019), inflammation (AOR, 9.44; 95% CI, 2.30-18.77; P=0.002), phosphocalcic product (AOR, 6.25; 95% CI, 1.19-12.87; P=0.031), and cardiac arrhythmias (AOR, 3.78; 95% CI, 1.55-7.81, P=0.009). Cumulative survival was worse among patients with PAD present (log-rank; P=0.032). CONCLUSION: The presence of PAD was a common finding in the present study, and associated with both traditional and emerging cardiovascular risk factors as well as a worse survival rate than patients without PAD.

Prevalence, Location, and Determinants of Valvular Calcifications in Congolese Patients on Chronic Hemodialysis: A Multicenter Cross-Sectional Study.

Valvular calcifications (VCs) are one of the major cardiovascular complications in patients on chronic hemodialysis (HD) due to its prevalence and predictive morbidity and mortality. The current study assessed the prevalence, location, and risk factors of VC among chronic HD Congolese patients in Kinshasa. This observational study involved three HD centers in Kinshasa between March and August 2016. Consecutive consenting adults on maintenance HD for at least six months were recruited. VCs were defined as a luminous echo on one or more cusps of the aortic or mitral valve. Risk factors of VC were determined by multivariate analysis. Sixty patients (mean age: 52.5 ± 15.9 years) were enrolled. The mean serum calcium and phosphorus were7.9 ± 1.3 mg/dL and 5.7 ± 1.7 mg/dL, respectively. VCs were encountered in 38% of the whole group in aortic and mitral valvular location in 64% and 23%, respectively. Hypertension, age >60 years, tobacco use, and hyperphosphatemia were independently associated with VC. Despite a young age of patients, VCs were a common finding and associated with both traditional and chronic kidney disease-specific risk factors.

Prevalence and factors associated with pulmonary arterial hypertension on maintenance hemodialysis patients in Kinshasa, Democratic Republic of Congo: a cross-sectional study.

BACKGROUND: Although cardiovascular diseases in particular Pulmonary Arterial Hypertension (PAH) is associated with, high morbid-mortality in chronic hemodialysis, but its magnitude remains paradoxically unknown in sub-Saharan Africa. The aim of this study was to evaluate the prevalence of PAH and associated factors in chronic hemodialysis in Sub-Saharan African population. METHOD: In a cross-sectional study, patients treated with HD for at least 6 months in 4 hemodialysis centers were examined. PAH was defined as estimated systolic pulmonary arterial pressure (sPAP) ≥ 35 mmHg using transthoracic Doppler echocardiography performed 24 h after the HD session. RESULTS: Eighty-five HD patients were included; their average age was 52.6 ± 15.9 years. Fifty-seven patients (67.1%) were male. Mean duration of HD was 13.3 ± 11 months. With reference to vascular access, 12 (14.1%), 29 (34.1%) and 44 (51.8%) patients had AVF, tunneled cuff and temporary catheter, respectively. The underlying cause of ESRD was diabetes in 30 patients (35.3%). The prevalence of PAH was 29.4%. Patients with PAH had more hyponatremia (11 (44%) vs 10 (16.7%), p = 0.010). In multivariate analysis, unsecured healthcare funding (aOR 4, 95% CI [1.18-6.018]), arrhythmia (aOR 3, 95% CI [1.29-7.34]), vascular access change (aOR 4, 95% CI [1.18-7.51]) and diastolic dysfunction (aOR 5, 95% CI [1.35-9.57] were independently associated with PAH. CONCLUSION: One third of hemodialysis patients exhibit PAH, which is independently associated with low socioeconomic status (unsecured funding, vascular access change) and cardiovascular complications (arrhythmia, diastolic dysfunction).

Cost estimate of chronic hemodialysis in Kinshasa, the Democratic Republic of the Congo: A prospective study in two centers.

BACKGROUND: The number of patients on dialysis has significantly increased worldwide. However, prospective studies estimating the cost of hemodialysis (HD) in sub-Saharan Africa remain scarce. The present study aimed to evaluate the direct cost of treating end stage renal disease. Determinants of additional direct cost were also assessed. METHODS: This study is an analytical, prospective study of cost performed at two HD centers in Kinshasa for a period of 3 months among HD patients enrolled consecutively. The cost analyzed includes only expenditures: consultation, HD session, drugs, comorbidities, laboratory tests, and imaging. Transportation, patient hospitalization, and indirect costs are not taken into account. The determinants of the additional direct cost of HD are identified by multivariate logistic regression analysis. P < 0.05 is the level of statistical significance. FINDINGS: The average quarterly direct cost of chronic HD in United States Dollars (US$) is $7070 (~US$28,280 annual cost) at a rate of US$287 per patient per HD session. This cost includes the HD session (US$237) and medicine (US$33) costs, which account for 82.5% and 11.3% of the direct costs, respectively. The presence of at least 4 comorbidities (OR adjusted 4.3, 95% CI [1.23-14.95], P = 0.022) and infection (adjusted OR 4.56, 95% CI [1.05-19.85], P = 0.043) emerged as independent determinants of additional direct cost. CONCLUSION: The direct cost of HD is very high in Kinshasa, where more than 80% of Congolese people live on less than US$1.25 a day.

G1 is the major APOL1 risk allele for hypertension-attributed nephropathy in Central Africa.

BACKGROUND: Sub-Saharan Africans exhibit a higher frequency of chronic kidney disease (CKD) than other populations. In this study, we sought to determine the frequency of apolipoprotein L1 (APOL1) genotypes in hypertension-attributed CKD in Kinshasa, Democratic Republic of the Congo. METHODS: We performed a case-control study identifying 162 subjects: 79 with hypertension-attributed CKD and 83 controls living in Kinshasa who were genotyped for APOL1 risk variants between July 2013 and November 2016. We selected control subjects from the general population and matched them with the cases according to age. Logistic regression analysis was used to examine the relationship between APOL1 high-risk genotypes and CKD. RESULTS: The frequencies of the APOL1 G1 and G2 alleles were 19.1 and 7.1%, respectively. The number of individuals with the G1 and G2 risk alleles was significantly higher in the CKD group (12.7%) than in the control group (2.4%), particularly in individuals with end-stage kidney disease (14.3%). Subjects carrying two risk alleles was strongly and independently associated with hypertension-attributed nephropathy, with an adjusted odds ratio of 7.7 (95% confidence interval 1.5-39.7; P = 0.014). The high-risk APOL1 genotypes were G1/G1 and G1/G2, whereas G2/G2 was not found in the study population. CONCLUSIONS: The results of this study demonstrate the association of high-risk APOL1 genotypes with kidney disease in Kinshasa. The absence of G2/G2 may be consistent with powerful selective sweeps induced by Trypanosoma brucei gambiense infection. In contrast, the presence of APOL1 G2/G2 among individuals of African ancestry in the USA may indicate relaxation of natural selection in a trypanosome-free environment.

Performance of creatinine- or cystatin C-based equations to estimate glomerular filtration rate in sub-Saharan African populations.

Glomerular filtration rate (GFR) is the best index for kidney function; however, the applicability of GFR estimating equations in sub-Saharan African populations remains unclear. In a cross-sectional study of adults living in Kinshasa, Democratic Republic of Congo (n=210) and Abidjan, Ivory Coast (n=284), we evaluated the performance of creatinine and cystatin C-based equations using plasma clearance of iohexol as the reference standard. The race coefficient did not improve the performance of creatinine-based GFR estimates; in fact, both the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology (CKD-EPI) equations performed better without the race coefficient in participants with GFR ≥60 mL/min/1.73m2. The CKD-EPI and Full Age Spectrum (FAS) equations were unbiased and had similar precision (SD of 17.9 versus 19 mL/min/1.73 m2) and accuracy within 30% (P30, 86.7% versus 87.4%) in participants with GFR ≥60 mL/min/1.73m2. Both equations performed poorly in the subgroup with measured GFR < 60 mL/min/1.73m2 (n=80), but the FAS equation had smaller bias (-4.8 mL/min/1.73m2 versus -7.7 mL/min/1.73m2 for CKD-EPI) and higher P30 (56.3% versus 31.3% for CKD-EPI). The corresponding equations including cystatin C alone or in combination with creatinine had similar performance. In a sub-Saharan African population, adjustment for race did not improve the performance of GFR estimating equations. The creatinine-based FAS and CKD-EPI equations performed reasonably well and were comparable when GFR was ≥ 60 mL/min/1.73m2. Cystatin C did not improve performance. The FAS equation may be preferable when GFR is < 60 mL/min/1.73m2, but this should be confirmed in larger studies.

Albuminuria status and patterns of dyslipidemia among type 2 diabetes black patients managed at a tertiary health-care hospital: A Post hoc analysis.

Cardiovascular disease (CVD) risk in type 2 diabetes mellitus (T2DM) increases with the development of albuminuria and is related in part to dyslipidemia. The present analysis assessed lipid profile and patterns of dyslipidemia in T2DM patients according to albuminuria status. This was a post hoc analysis of data from 181 T2DM patients seen at a tertiary health-care hospital and enrolled in a cross-sectional study of albuminuria status. Abnormal albuminuria was defined as microalbuminuria [albumin to creatinine ratio (ACR) 30-299.9 mg/g] or macro-albuminuria (ACR ≥300 mg/g). Atherogenic dyslipidemia was defined as triglycerides (TGs) ≥150 mg/dL and/or high-density lipoprotein-cholesterol (HDL-c) <40 mg/dL in men and <50 mg/dL in women using international consensus criteria. High levels of total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), HDL-c, non-HDL-c, TG, and low level of HDL-c were defined according to 2012 American Association of Clinical Endocrinologists' guidelines. Comparisons between T2DM patients with and without abnormal albuminuria were done using Chi-square test, Student's t-test, or two-sample t-test with equal variance and Mann-Whitney test as appropriate. P< 0.05 defined the level of statistical significance. Of the 181 T2DM patients, 93 (51%) had abnormal albuminuria with 32% and 19% having microalbuminuria and macro-albuminuria, respectively. Average TC, HDL-c, HDL-c, non-HDL-c, and TG levels were 171 ± 41, 111 ± 36, 38 ± 16, 133 ± 38, and 98 (45-234) mg/dL, respectively. These values were significantly lower for TC (P = 0.047), LDL-c (P = 0.030), and non-HDL-c (P = 0.05) in comparison with patients with normal albuminuria. Low HDL-c (64.5%) and high TG (9.7%) were, respectively, the most and less frequent patterns of isolated dyslipidemia in patients with abnormal albuminuria. Atherogenic dyslipidemia with mainly low HDL-c levels is common in T2DM patients with abnormal albuminuria and could contribute to CVD and renal disease progression.

Factors associated with residual urine volume preservation in patients undergoing hemodialysis for end-stage kidney disease in Kinshasa.

BACKGROUND: Decreased residual urine volume (RUV) is associated with higher mortality in hemodialysis (HD). However, few studies have examined RUV in patients on HD in Sub-Saharan Africa. The aim of this study was to identify predictors of RUV among incident hemodialysis patients in Kinshasa. METHODS: This historical cohort study enrolled 250 patients with ESRD undergoing hemodialysis between January 2007 and July 2013 in two hemodialysis centers in Kinshasa. RUV were collected over 24 h at the initiation of HD and 6 and 12 months later during the interdialytic period. We compared the baseline characteristics of the patients according to their initial RUV (≤ 500 ml/day vs >  500 ml/day) using Student's t, Mann-Whitney U and Chi2 tests. Linear mixed-effects models were used to search for predictors of decreased RUV by adding potentially predictive baseline covariates of the evolution of RUV to the effect of time: age, sex, diabetes mellitus, hypertension, diastolic blood pressure, diuretics, angiotensin conversion enzyme inhibitors (ACEI), angiotensin receptor blockers, hypovolemia, chronic tubulointerstitial nephropathy, left ventricular hypertrophy and initial hemodialysis characteristic. A value of p < 0.05 was considered the threshold of statistical significance. RESULTS: The majority of hemodialysis patients were male (68.8%, sex ratio 2.2), with a mean age of 52.5 ± 12.3 years. The population's RUV decreased with time, but with a slight deceleration. The mean RUV values were 680 ± 537 ml/day, 558 ± 442 ml/day and 499 ± 475 ml/day, respectively, at the initiation of HD and at 6 and 12 months later. The use of ACEI at the initiation of HD (beta coefficient 219.5, p < 0.001) and the presence of chronic tubulointerstitial nephropathy (beta coefficient 291.8, p = 0.007) were significantly associated with RUV preservation over time. In contrast, the presence of left ventricular hypertrophy at the initiation of HD was significantly associated with decreased RUV over time (beta coefficient - 133.9, p = 0.029). CONCLUSIONS: Among incident hemodialysis patients, the use of ACEI, the presence of chronic tubulointerstitial nephropathy and reduced left ventricular hypertrophy are associated with greater RUV preservation in the first year of dialysis.

Performance of glomerular filtration rate estimation equations in Congolese healthy adults: The inopportunity of the ethnic correction.

CONTEXT AND OBJECTIVE: In the estimation of glomerular filtration rate (GFR), ethnicity is an important determinant. However, all existing equations have been built solely from Caucasian and Afro-American populations and they are potentially inaccurate for estimating GFR in African populations. We therefore evaluated the performance of different estimated GFR (eGFR) equations in predicting measured GFR (mGFR). METHODS: In a cross-sectional study, 93 healthy adults were randomly selected in the general population of Kinshasa, Democratic Republic of the Congo, between June 2015 and April 2016. We compared mGFR by plasma clearance of iohexol with eGFR obtained with the Modified Diet in Renal Disease (MDRD) equation with and without ethnic factor, the Chronic Kidney Disease Epidemiology (CKD-EPI) serum creatinine (SCr)-based equation, with and without ethnic factor, the cystatin C-based CKD-EPI equation (CKD-EPI SCys) and with the combined equation (CKD-EPI SCrCys) with and without ethnic factor. The performance of the equations was studied by calculating bias, precision and accuracy within 30% (P30) of mGFR. RESULTS: There were 48 women and 45 men. Their mean age was 45.0±15.7 years and the average body surface area was 1.68±0.16m2. Mean mGFR was 92.0±17.2 mL/min/1.73m2 (range of 57 to 141 mL/min/1.73m2). Mean eGFRs with the different equations were 105.5±30.1 and 87.2±24.8 mL/min/1.73m2 for MDRD with and without ethnic factor, respectively; 108.8±24.1 and 94.3x20.9 mL/min/1.73m2 for CKD-EPI SCr with and without ethnic factor, respectively, 93.5±18.6 mL/min/1.73m2 for CKD-EPI SCys; 93.5±18.0 and 101±19.6 mL/min/ 1.73m2 for CKD-EPI SCrCys with and without ethnic factor, respectively. All equations slightly overestimated mGFR except MDRD without ethnic factor which underestimated by -3.8±23.0 mL/min /1.73m2. Both CKD-EPI SCr and MDRD with ethnic factors highly overestimated mGFR with a bias of 17.9±19.2 and 14.5±27.1 mL/min/1.73m2, respectively. There was a trend for better P30 for MDRD and CKD-EPI SCr without than with the ethnic factor [86.0% versus 79.6% for MDRD (p = 0.21) and 81.7% versus 73.1% for the CKD-EPI SCr equations (p = 0.057)]. CKD-EPI SCrCys and CKD-EPI SCys were more effective than creatinine-based equations. CONCLUSION: In the Congolese healthy population, MDRD and CKD-EPI equations without ethnic factors had better performance than the same equations with ethnic factor. The equations using Cys C (alone or combined with SCr) performed better than the creatinine-based equations.

Reverse epidemiology of elevated blood pressure among chronic hemodialysis black patients with stroke: a historical cohort study.

BACKGROUND: Stroke is the third leading cause of cardiovascular mortality in dialysis patients. The objective of this study was to assess the extent of stroke in chronic hemodialysis patients. METHODS: Historical cohort of patients enrolled in two hemodialysis (HD) centers from January 1, 2010 to December 31, 2011, including 191 patients (mean age 52 years, 68% men). Incidence curves and survival time analysis between the first day of HD and the end of the study were described by the Kaplan-Meier method. Independent stroke predictors were identified by multiple logistic regression analysis. P < 0.05 defined the level of statistical significance. RESULTS: 12 incident stroke were recorded during the study period, with 1622.1 person-months (PM), a stroke incidence rate of 7.4 cases per 1000 PM (95% CI = 7.35-7.44) at the point date. The incidence of stroke at 6 months, 12 months and 24 months was 9.8%, 11.9% and 13%, respectively. Only the absence of arterial hypertension (RR = 5.7, 95% CI: 1.52-21.42) emerged as an independent determinant of stroke. CONCLUSION: The high incidence of stroke in Kinshasa HD centers is partially explained by reverse epidemiology. Efforts must be made to understand this phenomenon in order to reduce its impact.

Albuminuria, serum antioxidant enzyme levels and markers of hemolysis and inflammation in steady state children with sickle cell anemia.

BACKGROUND: Oxidative stress is thought to be involved in the pathogenesis of microalbuminuria in Sickle cell anemia (SCA). Antioxidant enzymes such as glutathione peroxidase (GPx) and Cu-Zn superoxide dismutase (SOD) may play an important protective role. This study aimed to evaluate the association between albuminuria and these two antioxidant enzymes. METHODS: We consecutively recruited Steady state children aged between 2 and 18 years old with established diagnosis of homozygous SCA in two hospitals of Kinshasa/DR Congo. The relationship between Urinary Albumin Creatinine Ratio (UACR) and other variables of interest (age, systolic blood pressure, diastolic blood pressure, plasma GPx and Cu-Zn SOD, free plasmatic hemoglobin, LDH, indirect bilirubin, white blood cells (WBC), percentage of fetal hemoglobin, serum iron, ferritin, CRP) was analyzed by Bivariate correlation (Pearson's correlation coefficient). Microalbuminuria was defined by urine albumin/creatinine ratio between 30 and 299 mg/g. RESULTS: Seventy Steady state Black African children with SCA (56% boys; average age 9.9 ± 4.3 years; 53% receiving hydroxyurea) were selected. Prevalence of microalbuminuria was 11.8%. LDH (r = 0.260; p = 0.033) and WBC count (r = 0.264; p = 0.033) were positively correlated with UACR whereas GPx (- 0.328; p = 0.007) and Cu-Zn SOD (- 0.210; p = 0.091) were negatively correlated with UACR. CONCLUSIONS: Albuminuria is associated with decreased antioxidant capacity and increased levels of markers of hemolysis and inflammation. Therefore, strategies targeting the reduction of sickling and subsequent hemolysis, oxidative stress and inflammation could help preventing or at least delaying the progression of kidney disease in SCA children.

Impact of residual urine volume decline on the survival of chronic hemodialysis patients in Kinshasa.

BACKGROUND: Despite the multiple benefits of maintaining residual urine volume (RUV) in hemodialysis (HD), there is limited data from Sub-Saharan Africa. The aim of this study was to assess the impact of RUV decline on the survival of HD patients. METHODS: In a retrospective cohort study, 250 consecutive chronic HD patients (mean age 52.5 years; 68.8% male, median HD duration 6 months) from two hospitals in the city of Kinshasa were studied, between January 2007 and July 2013. The primary outcome was lost RUV. Preserved or lost RUV was defined as decline RUV < 25 (median decline) or ≥ 25 ml/day/month, respectively. The second endpoint was survival (time-to death). Survival curves were built using the Kaplan-Meier methods. We used Log-rank test to compare survival curves. Predictors of mortality were assessed by Cox proportional hazards regression models. RESULTS: The cumulative incidence of patients with RUV decline was 52, 4%. The median (IQR) decline in RUV was 25 (20.8-33.3) ml/day/month in the population studied, 56.7 (43.3-116.7) in patients deceased versus 12.9 (8.3-16.7) in survivor patients (p < 0.001). Overall mortality was 78 per 1000 patient years (17 per 1000 in preserved vs 61 per 1000 lost RUV). Forty six patients (18.4%) died from withdrawal of HD due to financial constraints. The Median survival was 17 months in the whole group while, a significant difference was shown between lost (10 months, n = 119) vs preserved RUV group (30 months, n = 131; p = 0001). Multivariate Cox proportional hazards models showed that, decreased RUV (adjusted HR 5.35, 95% CI [2.73-10.51], p < 0.001), financial status (aHR 2.23, [1.11-4.46], p = 0.024), hypervolemia (a HR 2.00, [1.17-3.40], p = 0.011), lacking ACEI (aHR 2.48, [1.40-4.40], p = 0.002) or beta blocker use (aHR 4.04, [1.42-11.54], p = 0.009), central venous catheter (aHR 6.26, [1.71-22.95], p = 0.006), serum albumin (aHR 0.93, [0.89-0.96], p < 0.001) and hemoglobin (aHR 0.73, [0.63-0.84], p < 0.001) had emerged as the independent predictors of all-cause mortality. CONCLUSION: More than half of HD patients in this cohort study experienced fast RUV decline which contributed substantially to increase mortality, highlighting the need for its prevention and management.

[Predictors of physical incapacity degree to chronic hemodialysis patients in Kinshasa : Key role of the residual diuresis]. / Prédicteurs du degré d'incapacité physique chez les hémodialysés de Kinshasa : rôle primordial de la diurèse résiduelle.

OBJECTIVE: Identifying predictors of physical incapacity degree in patients on chronic hemodialysis in Kinshasa. METHODS: Bicentric analytical study, between January 2007 and July 2013. Degree of physical handicap was evaluated at 6months of hemodialysis based on the scale of Rosser. Logistic regression sought the predictors of no or light physical incapacity (Rosser<3) vs. moderate to maximum (Rosser≥3). P was set at 0.05. RESULTS: One hundred twenty-seven patients (127) patients received at least 6months of hemodialysis (53.3±11years; 73.2 % male), 79 (62.2 %) had no or light incapacity and 48 (37.8 %) moderate to maximum. Predictors of lower physical incapacity in univaried analysis were: secured funding, high socioeconomic level, lack of diabetes mellitus, high body weight, normal systolic and diastolic blood pressure, residual diuresis 3months later, hemoglobin and hematocrit, low comorbidity, arteriovenous fistula, erythropoietin, at least 12hours of hemodialysis per week and lack of intradialytic complications. After logistic regression, a high residual diuresis 3months of hemodialysis has proved an independent predictor of lower physical Incapacity (aOR 0.998; P=0.024) next to the lack of diabetes mellitus (aOR 0.239; P=0.024), good control of systolic (aOR 0.958; P=0.013) and diastolic (aOR 1.089; P=0.003) blood pressure and the use of erythropoietin (aOR 5.687; P=0.004). CONCLUSION: Preserving residual diuresis is associated with lower physical incapacity and must be integrated in the management in hemodialysis.

Acute kidney injury is a powerful independent predictor of mortality in critically ill patients: a multicenter prospective cohort study from Kinshasa, the Democratic Republic of Congo.

BACKGROUND: Despite the growing incidence of acute kidney injury (AKI) worldwide, there is little data on the burden and outcomes of AKI in intensive care unit (ICU) in low resource settings. The present study assessed the incidence of AKI and its impact on mortality in ICU in Kinshasa (Democratic Republic of Congo). METHODS: In a prospective cohort study, 476 consecutive critically ill patients (mean age 52 years, 57 % male) were screened for the presence of AKI in seven ICU from January 1st to March 30th, 2015. Serum creatinine was measured by the enzymatic method (Cobas C111 device®). AKI and its stages (no AKI, AKI 1, AKI 2 and AKI 3) were defined according to AKIN recommendations. The primary outcome was 28 days mortality. Survival (time-to death) curves were built using the Kaplan Meier methods. Predictors of mortality were assessed by Cox proportional hazards regression models. p < 0.05 defined the level of statistical significance. RESULTS: The cumulative incidence of AKI was 52.7 % with AKI stage 1, 2 and 3 in 23.7 %, 16.2 % and 12.8 % of patients, respectively. Among patients who developed AKI, 146 died (58 %) vs 62 patients (28 %) in the group without AKI. Only 6.5 % of the patients with AKI stage 3 benefited from dialysis. Median survival time was 15.0 days in patients without AKI and 3.0 days, 6.0 days and 8.0 days in patients with AKI stage 3, 2 and 1 (p < 0.001), respectively. In addition to respiratory distress-induced polypnea (HRa 1.60; 95 % CI: 1.08-2.37; p = 0.018), oxygen desaturation (HRa 1.53; 95 % CI: 1.13-2.08; p = 0.006) and multi-organic involvement (HRa 1.63; 95 % CI: 1.15-2.30), AKI emerged as an independent predictor of death (HRa 1.82; 95 % CI: 1.34-2.48; p < 0.001). CONCLUSION: More than half of critically ill patients in the present cohort developed AKI which contributed substantially to short-term mortality, highlighting the need for its prevention, early detection and management as well as the availability of dialysis in ICU.

Prevalence of low estimated glomerular filtration rate, proteinuria, and associated risk factors among HIV-infected black patients using Cockroft-Gault and modification of diet in renal disease study equations.

OBJECTIVE: To evaluate the prevalence of low estimated glomerular filtration rate (eGFR), proteinuria, and associated risk factors among HIV-infected black patients at primary health care. METHODS: A cross-sectional screening involving consecutive HIV-infected patients 18 years and older was done. Eighty-eight percent of patients were receiving highly active antiretroviral therapy (94% on first-line regimen: zidovudine + lamivudine + nevirapine). Simplified Modification of Diet in Renal Disease Study and Cockroft-Gault (CG) equations were used to estimate glomerular filtration rate and creatinine clearance, respectively. Determinants of dipstick proteinuria and low kidney function (<60 mL·min(-1)·1.73 m(-2)) were assessed using multivariate logistic regression analysis. RESULTS: Three hundred HIV-infected (231 females) patients were screened. Their mean age, duration of HIV, and CD4(+) count were 43 ± 9 years, 33 ± 27 months, and 397 ± 224 cells per cubic millimeter, respectively. The prevalence of low eGFR according to Modification of Diet in Renal Disease Study and CG equations was 3% and 10%, respectively. Proteinuria was observed in 20.5% of patients. Only CD4(+) cell count ≤200 cells per cubic millimeter emerged as a strong determinant of low CG creatinine clearance [adjusted odds ratio (OR) 3.03; 95% confidence interval (CI): 1.099 to 8.352], whereas age ≥45 years (adjusted OR 3.69; 95% CI: 1.756 to 7.787), familial history of diabetes mellitus (adjusted OR 2.20; 95% CI: 1.067 to 4.543), and hypertension (adjusted OR 3.07; 95% CI: 1.278 to 7.787) were significantly associated with proteinuria. CONCLUSIONS: Low eGFR and proteinuria are prevalent among these HIV-infected persons. Immunodeficiency emerged as one of the strongest determinants of renal impairment. This finding emphasizes the importance of highly active antiretroviral therapy in tackling the burden of chronic kidney disease in African HIV population.