Neglected and Emerging Infections of The Kidney

Individuals, societies, and the environment are affected by neglected and emerging diseases. These diseases result in a variety of severe outcomes, including permanent disabilities, chronic diseases such as chronic kidney disease, and even mortality. Consequences include high health care expenditures, loss of means of support, social stigma, and social exclusion. The burden of these diseases is exacerbated in low- and middle-income countries owing to poverty, inadequate fundamental infrastructure, and the absence of health and social protection systems. The World Health Organization is committed to promoting the following public health strategies to prevent and control neglected tropical diseases: preventive chemotherapy; intensive case management; vector control; provision of safe drinkable water, sanitation, and hygiene; and veterinary public health. In addition, it promotes a One Health strategy, which is a collaborative, multisectoral, and interdisciplinary approach to achieving the greatest health outcomes by recognizing the interdependence of human beings, animals, plants, and their shared environment. This article provides knowledge and strategies for the prevention and treatment of neglected and emerging diseases, with a particular concentration on kidney diseases, as part of a comprehensive approach to One Health.

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.

Cardiovascular Risk Factor Burden and Association With CKD in Ghana and Nigeria

Introduction

Cardiovascular disease is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD); however, the burden of cardiovascular risk factors in patients with CKD in Africa is not well characterized. We determined the prevalence of selected cardiovascular risk factors, and association with CKD in the Human Heredity for Health in Africa Kidney Disease Research Network study.

Methods

We recruited patients with and without CKD in Ghana and Nigeria. CKD was defined as estimated glomerular filtration rate of <60 ml/min per 1.73 m2 and/or albuminuria as albumin-to-creatinine ratio <3.0 mg/mmol (<30 mg/g) for ≥3 months. We assessed self-reported (physician-diagnosis and/or use of medication) hypertension, diabetes, and elevated cholesterol; and self-reported smoking as cardiovascular risk factors. Association between the risk factors and CKD was determined by multivariate logistic regression.

Results

We enrolled 8396 participants (cases with CKD, 3956), with 56% females. The mean age (45.5 ± 15.1 years) did not differ between patients and control group. The prevalence of hypertension (59%), diabetes (20%), and elevated cholesterol (9.9%), was higher in CKD patients than in the control participants (P < 0.001). Prevalence of risk factors was higher in Ghana than in Nigeria. Hypertension (adjusted odds ratio [aOR] = 1.69 [1.43-2.01, P < 0.001]), elevated cholesterol (aOR = 2.0 [1.39-2.86, P < 0.001]), age >50 years, and body mass index (BMI) <18.5 kg/m2 were independently associated with CKD. The association of diabetes and smoking with CKD was modified by other risk factors.

Conclusion

Cardiovascular risk factors are prevalent in middle-aged adult patients with CKD in Ghana and Nigeria, with higher proportions in Ghana than in Nigeria. Hypertension, elevated cholesterol, and underweight were independently associated with CKD.

Systematic review of international studies evaluating MDRD and CKD-EPI estimated glomerular filtration rate (eGFR) equations in Black adults

Use of race adjustment in estimating glomerular filtration rate (eGFR) has been challenged given concerns that it may negatively impact the clinical care of Black patients, as it results in Black patients being systematically assigned higher eGFR values than non-Black patients. We conducted a systematic review to assess how well eGFR, with and without race adjustment, estimates measured GFR (mGFR) in Black adults globally. A search across multiple databases for articles published from 1999 to May 2021 that compared eGFR to mGFR and reported outcomes by Black race was performed. We included studies that assessed eGFR using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICr) creatinine equations. Risk of study bias and applicability were assessed with the QUality Assessment of Diagnostic Accuracy Studies-2. Of 13,167 citations identified, 12 met the data synthesis criteria (unique patient cohorts in which eGFR was compared to mGFR with and without race adjustment). The studies included patients with and without kidney disease from Africa (n = 6), the United States (n = 3), Europe (n = 2), and Brazil (n = 1). Of 11 CKD-EPI equation studies, all assessed bias, 8 assessed accuracy, 6 assessed precision, and 5 assessed correlation/concordance. Of 7 MDRD equation studies, all assessed bias, 6 assessed accuracy, 5 assessed precision, and 3 assessed correlation/concordance. The majority of studies found that removal of race adjustment improved bias, accuracy, and precision of eGFR equations for Black adults. Risk of study bias was often unclear, but applicability concerns were low. Our systematic review supports the need for future studies to be conducted in diverse populations to assess the possibility of alternative approaches for estimating GFR. This study additionally provides systematic-level evidence for the American Society of Nephrology-National Kidney Foundation Task Force efforts to pursue other options for GFR estimation.

Examining Socioeconomic Status of Patients with Chronic Kidney Disease Attending Renal Clinic in Southeast Nigeria: A Single Centre Experience

BACKGROUND

There are few reports on socioeconomic status (SES) of patients with chronic kidney disease (CKD) in Nigeria and indeed Africa, South of the Sahara. Identifying SES as an important factor for disability in people with CKD would provide a means for early identification of those at risk and, possible intervention.

OBJECTIVE

To determine the SES of CKD patients attending renal clinic in the University of Nigeria Teaching Hospital.

METHODS

Cross-sectional descriptive design was adopted using pretested questionnaire to elicit data on SES (age, place of residence, household asset ownership, source of drinking water; source of cooking energy; and type of toilet facility) from one hundred and forty-five (145) CKD patients attending renal clinic in the University of Nigeria Teaching Hospital. Principal component analysis was used to classify the SES into five quintiles.

RESULTS

Majority of the respondents (patients) in stages 4 and 5 CKD, constituting 17.2% and 39.3% respectively were from the lower SES. There was significant correlation between SES and age of the patients; place of residence; hypertension history; ownership of some household assets; source of drinking water; source of cooking energy; and type of toilet facility.

CONCLUSION

This study demonstrated that many of our patients were from the lower SES. It is recommended that both governmental and non-governmental agencies should help these patients with some form of health insurance to alleviate their healthcare cost burden.

Posttransplant Care of Kidney Transplant Recipients and Their Donors in Nigeria

OBJECTIVES

Kidney transplantation is not readily available in low-resource settings because of poor health structure, dearth of experts, and pervading poverty. Although many centers now offer kidney transplant, patients still travel outside Nigeria for this service for many reasons and many return home without a detailed medical report.

MATERIALS AND METHODS

Medical records of individuals who underwent kidney transplant in Nigeria and elsewhere and who were presently receiving posttransplant care or had received such care from 2002 to 2018 at 4 Nigerian hospitals were retrospectively reviewed and analyzed.

RESULTS

Of 35 patients (30 males; 85.7%) analyzed (mean ages of 42 ± 16 and 47 ± 8 years for men and women, respectively; P = .54), common primary kidney diseases included hypertension (27.2%), glomerulonephritis (24.2%), and diabetes mellitus/hypertension (18.3%). Most patients received transplants in India (48.6%), with others in Nigeria (23.0%) and Pakistan (8.6%). Relationships to recipient were unrelated (28.5%), living related (22.9%), and unknown (48.6%). Less than 30% of recipients had care details in their hospital records. Almost all transplant patients were treated with prednisolone (81.8%); cyclosporine (40.0%), mycophenolate mofetil (31.4%), tacrolimus (20.0%), and azathioprine (9.1%) were also used. Complications were documented in 88.9%, with 57.0% due to bacterial infections/sepsis. Many (88.9%) had more than 2 complications. In follow-up, median first transplant duration was 24 months (interquartile range, 6-44). Of total patients, 25.7% were still alive, 17.1% had died, and 54.2% were lost to follow-up. Follow-up data for only 2 donors were available.

CONCLUSIONS

Lapses in follow-up care of kidney transplant recipients and donors continue in lowresource settings where transplant tourism is still rife, resulting in poor graft/patient survival. Adherence to transplant guidelines is advocated. We propose a transplant stratification model according to level of development and resources of countries or regions. This model will encourage customizing strategies for improving patient outcomes.

Predictors of autonomic dysfunction among predialysis chronic kidney disease patients in Nigeria

Background

Chronic kidney disease (CKD) is a global public health problem with increasing incidence and mortality in Africa. Autonomic dysfunction (AD) has been implicated as a major contributor to the disease morbidity and mortality, but little is known about the predictors of this dysfunction in African populations. Understanding the predictors of this condition is necessary for early detection and management of CKDs. Objectives: This study was designed to determine the predictors of AD in CKD patients in Nigeria.

Materials and Methods

It was a cross-sectional study of CKD patients at University of Nigeria Teaching Hospital, Enugu, Nigeria. The CKD patients with AD were compared with those without AD and a normal control group. Autonomic function was assessed through noninvasive cardiovascular tests: measurement of resting tachycardia, orthostatic hypotension, heart rate response (HRR) to standing, HRR to Valsalva maneuvre, and HRR to respiration. Data on symptoms of CKD and AD were obtained using a validated questionnaire.

Results

The mean age of the CKD patients was 41.3 ± 1.5 (range: 21-69) years. Early hospital presentation is associated with significantly less risk of the development of AD (P < 0.001). Dizziness, nocturnal diarrhea, and impotence are the major markers/predictors of AD in CKD patients (P < 0.05).

Conclusion

AD is common among predialysis CKD patients in Nigeria, and best predicted by the presence of postural dizziness, nocturnal diarrhea, and impotence in men. Physicians should, therefore, be on the lookout for these features for prompt and adequate management of cases.

Cardiovascular disease risk factors in a Nigerian population with impaired fasting blood glucose level and diabetes mellitus

Background

Diabetes is a risk factor for cardiovascular diseases (CVDs) and there are reports of increasing prevalence of prediabetes in Nigeria. This study therefore characterised CVDs risk factors in subjects with impaired fasting glucose (IFG) and diabetes.

Methods

Data from 4 population-based cross-sectional studies on 2447 apparently healthy individuals from 18 - 89 years were analysed. Anthropometric, blood pressure and biochemical parameters were collected and classified. Individuals with IFG (prediabetes) and diabetes were merged each for positive cases of dyslipidaemia, high blood pressure (HBP) or obesity. Optimal Discriminant and Hierarchical Optimal Classification Tree Analysis (HO-CTA) were employed.

Results

Overall prevalence of IFG and diabetes were 5.8% (CI: 4.9 – 6.7%) and 3.1% (CI: 2.4 – 3.8%), respectively. IFG co-morbidity with dyslipidaemia (5.0%; CI: 4.1 – 5.8%) was the highest followed by overweight/obese (3.1%; CI: 2.5 – 3.8%) and HBP (1.8%; CI: 1.3 – 2.4%). The predicted age of IFG or diabetes and their co-morbidity with other CVD risk factors were between 40 – 45 years. Elevated blood level of total cholesterol was the most predictive co-morbid risk factor among IFG and diabetes subjects. Hypertriglyceridaemia was an important risk factor among IFG-normocholesterolaemic-overweight/obese individuals.

Conclusion

The higher prevalence of co-morbidity of CVD risk factors with IFG than in diabetes plus the similar age of co-morbidity between IFG and diabetes highlights the need for risk assessment models for prediabetes and education of individuals at risk about factors that mitigate development of diabetes and CVDs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3910-3) contains supplementary material, which is available to authorized users.

Maximum accuracy obesity indices for screening metabolic syndrome in Nigeria: A consolidated analysis of four cross-sectional studies

BACKGROUND

In sub-Saharan Africa, there is no precise use of metabolic syndrome (MetS) definitions and risk factors screening indices in many clinical and public health services. Methods proposed and used in Western populations are adopted without validation within the local settings. The aim of the study is to assess obesity indices and cut-off values that maximise screening of MetS and risk factors in the Nigerian population.

METHOD

A consolidated analysis of 2809 samples from four population-based cross-sectional study of apparently healthy persons≥18 years was carried out. Optimal waist circumference (WC) and waist-to-height ratio (WHtR) cut points for diagnosing MetS and risk factors were determined using Optimal Data Analysis (ODA) model. The stability of the predictions of the models was also assessed.

RESULTS

Overall mean values of BMI, WC and WHtR were 24.8±6.0kgm(-2), 84.0±11.3cm and 0.52±0.1 respectively. Optimal WC cut-off for discriminating MetS and diabetes was 83cm in females and 85cm in males, and 82cm in females and 89cm in males, respectively. WC was stable in discriminating diabetes than did WHtR and BMI, while WHtR showed better stability in predicting MetS than WC and BMI.

CONCLUSION

The study shows that the optimal WC that maximises classification accuracy of MetS differs from that currently used for sub-Saharan ethnicity. The proposed global WHtR of 0.50 may misclassify MetS, diabetes and hypertension. Finally, the WC is a better predictor of diabetes, while WHtR is a better predictor of MetS in this sample population.

Prevalence of CKD-MBD in pre-dialysis patients using biochemical markers in Enugu, South-East Nigeria

BACKGROUND

As kidney function declines, there is a progressive deterioration in mineral homeostasis with disruption of normal serum and tissue concentration of phosphorus and calcium, and changes in circulating levels of hormones-parathyroid hormone (PTH), calcitriol (1,25(OH)2 D), and Fibroblast growth factor-23 (FGF-23).

OBJECTIVE

This study was aimed at determining the prevalence of markers of CKD-MBD in pre-dialysis patients.

METHODS

We evaluated consecutively 168 subjects made up of 85 CKD patients and 83 healthy controls, who were attending the renal clinics and medical outpatient of University of Nigeria Teaching Hospital, Enugu. GFR was estimated and serum calcium, phosphorus, alkaline phosphatase, PTH, and 25(OH) D levels assayed.

RESULTS

The prevalence of various mineral bone disease abnormalities were 70% hyper-phosphatemia, 85% hyper-parathyroidism, and 100% low levels of 25 (OH) D among the patients. Estimated GFR correlated negatively with both serum phosphorus, and PTH. Age of the patients ranged from18-76 years with a male to female ratio of 1.7:1. Chronic Glomerulonephritis (CGN), hypertension and diabetes mellitus caused CKD in 75% of the patients. There was no significant decrease in serum calcium levels of patients compared to controls. The patients did not have pathologically raised alkaline phosphatase, although their mean level was significantly higher than that of the control group.

CONCLUSION

Low 25 (OH) D levels (insufficiency/deficiency), hyperparathyroidism, and hyper-phosphatemia were the obvious markers of CKD-MBD in our pre-dialysis patients. These should be evaluated at presentation in these patients.

Reference intervals for serum cystatin C and creatinine of an indigenous adult Nigerian population

BACKGROUND AND AIM

Estimation of the glomerular filtration rate (GFR) is important for the evaluation of patients with kidney disease. Some studies suggest that GFR estimated from serum cystatin C (Cys C) is more accurate than that from serum creatinine (SCr). For Cys C to be used for this purpose, normal values need to be determined for various populations. This study determined the serum Cys C levels and reference intervals (RIs) of a Nigerian population.

MATERIALS AND METHODS

Three hundred and four healthy adult subjects were analysed. Serum Cys C and SCr were determined by particle enhanced turbidimetric immunoassay and modified Jaffe kinetic method respectively. Data were analysed using the Statistical Package for Social Sciences version 17.0 (SPSS for Windows Inc., Chicago, IL, USA). Estimation of RIs was done as per the International Federation of Clinical Chemistry guidelines.

RESULTS

The RIs for Cys C were 0.65-1.12 mg/L (median 0.86) for males, 0.62-1.12 mg/L (median 0.85) for females and 0.64-1.12 mg/L (median 0.86) for all the subjects. The RIs for SCr were 73-110 μmol/L (median 89) for males, 65-102 μmol/L (median 82) for females and 66-106 μmol/L (median 86) for all the subjects. There was no significant gender difference in the RIs for serum Cys C, (P > 0.05). The SCr levels and RI were significantly lower in females than in males (P < 0.001).

CONCLUSION

This study has determined the serum Cys C levels and RI of an indigenous healthy adult black population in Nigeria.

Pattern of cancer deaths in the medical wards of a teaching hospital in South East Nigeria

BACKGROUND

Cancers are emerging public health problems in developing countries like Nigeria. The epidemiological shift and aging population make cancers a challenge.

OBJECTIVE

We set out to describe the pattern of death due to cancer in our medical ward. The hospital is one of the premier hospitals covering the South East zone of Nigeria.

MATERIALS AND METHODS

We retrospectively reviewed the case notes and death certificates of all who died of cancer in our adult medical wards for 16 years (January 1995 to December 2010).

STATISTICAL ANALYSIS USED

Statistical Package for Social Sciences (SPSS Inc. Chicago, IL) version 17.0 was used.

RESULTS

Twenty seven thousand, five hundred and fourteen patients were admitted into the medical wards. Six thousand, two hundred and fifty died. Out of the 6250 deaths, cancers accounted for 7.6%. Male to Female ratio was 2.4:1. The mean age at death was 43.7 ± 17.4 years. The mean age at death in both sexes was similar (42.9 ± 17.5 for men and 45.7 ± 17.0 years for women), P = 0.109. Primary liver cell carcinoma was the most common cause of death among men (40.8%), while cancer of hematopoietic organ was the most common in women (48.7%). The overall fatality rate was 1.7% (477/27 514) of medical admissions. Younger and middle age groups were most commonly affected in both sexes.

CONCLUSION

Since the most productive age groups were affected, governments in developing countries should as a matter of urgency put in place adequate cancer preventive and curative services.

Efficacy of newer versus older antihypertensive drugs in black patients living in sub-Saharan Africa

To address the epidemic of hypertension in blacks born and living in sub-Saharan Africa, we compared in a randomised clinical trial (NCT01030458) single-pill combinations of old and new antihypertensive drugs in patients (30-69 years) with uncomplicated hypertension (140-179/90-109 mm Hg). After ≥4 weeks off treatment, 183 of 294 screened patients were assigned to once daily bisoprolol/hydrochlorothiazide 5/6.25 mg (n=89; R) or amlodipine/valsartan 5/160 mg (n=94; E) and followed up for 6 months. To control blood pressure (<140/<90 mm Hg), bisoprolol and amlodipine could be doubled (10 mg per day) and α-methyldopa (0.5-2 g per day) added. Sitting blood pressure fell by 19.5/12.0 mm Hg in R patients and by 24.8/13.2 mm Hg in E patients and heart rate decreased by 9.7 beats per minute in R patients with no change in E patients (-0.2 beats per minute). The between-group differences (R minus E) were 5.2 mm Hg (P<0.0001) systolic, 1.3 mm Hg (P=0.12) diastolic, and 9.6 beats per minute (P<0.0001). In 57 R and 67 E patients with data available at all visits, these estimates were 5.5 mm Hg (P<0.0001) systolic, 1.8 mm Hg (P=0.07) diastolic and 9.8 beats per minute (P<0.0001). In R compared with E patients, 45 vs 37% (P=0.13) proceeded to the higher dose of randomised treatment and 33 vs 9% (P<0.0001) had α-methyldopa added. There were no between-group differences in symptoms except for ankle oedema in E patients (P=0.012). In conclusion, new compared with old drugs lowered systolic blood pressure more and therefore controlled hypertension better in native African black patients.

Seizure disorder among chronic kidney disease patients in Enugu, South East Nigeria

BACKGROUND

Seizures are the commonest neurological condition presenting in Africa. The pattern of non- epileptic seizures in systemic diseases including chronic kidney disease is unknown in South East Nigeria.

OBJECTIVES

This study examined the pattern of seizures in chronic kidney disease patients in Enugu, South East Nigeria.

METHODS

This was a retrospective study of chronic kidney disease patients who presented to the University of Nigeria Teaching Hospital Enugu (UNTH) from January 2007 December 2008. Data from subjects who satisfied the inclusion criteria were reviewed and analysed using Statistical Package for the Social Sciences version 13.5. Ethical clearance was obtained from the UNTH Ethics Committee.

RESULTS

There were 145 patients, 95 males and 50 females. Mean age was 35 years. Only 5 patients (3,4%) had seizures (mostly generalized tonic-clonic) associated with severe hypertension. None had hypocalcaemia. Three patients (60%) received dialysis with benefit while 2 patients (40%) died before dialysis could be done.

CONCLUSION

Seizures are infrequent in chronic kidney disease patients in Enugu; are commoner in males and those with severe disease. Dialysis improved survival in those with seizures. Larger multicentre studies are needed to further elucidate the spectrum of Nigeria.

Cardiovascular risk factors in middle-aged and elderly residents in South-East Nigeria: the influence of urbanization

Cardiovascular diseases (CVD) were previously considered a problem of the developed nations only. Emerging facts show that CVD and their risk factors are now prevalent in developing countries. We carried out a cross-sectional, population-based survey to determine the relation between place residence (rural or urban) and the burden of CVD risk factors in South East Nigeria. Hypercholesterolaemia, hypertension, abnormal blood glucose and obesity were assessed for, in middle-aged and elderly residents of two communities in Enugu, South East Nigeria. A total of 543 adults (308 at Ogwofia Owa and 235 at Emene) participated in the study. The mean and 95% CI for mean of the characteristics of subjects showed that they were in the middle-age group with apparently normal mean cardiovascular risk indices except for systolic and diastolic blood pressure indices which suggested pre-hypertension. The subjects residing in the rural area were older than those residing in the urban area but cardiovascular risk factors had higher mean values in urban residents except systolic blood pressure (SBP). The most prevalent cardiovascular risk factors in the study group were hypertension and obesity. Urban residence was found to influence the prevalence of risk factors, specifically obesity and diastolic hypertension.

Heart rate variability on antihypertensive drugs in black patients living in sub-Saharan Africa

Background

Compared with Caucasians, African Americans have lower heart rate variability (HRV) in the high-frequency domain, but there are no studies in blacks born and living in Africa.

Methods

In the Newer versus Older Antihypertensive agents in African Hypertensive patients trial (NCT01030458), patients (30–69 years) with uncomplicated hypertension (140–179/90–109 mmHg) were randomized to single-pill combinations of bisoprolol/hydrochlorothiazide (R) or amlodipine/valsartan (E). 72 R and 84 E patients underwent 5-min ECG recordings at randomization and 8, 16 and 24 weeks. HRV was determined by fast Fourier transform and autoregressive modelling.

Results

Heart rate decreased by 9.5 beats/min in R patients with no change in E patients (− 2.2 beats/min). R patients had reduced total (− 0.13 ms²; p = 0.0038) and low-frequency power (− 3.6 nu; p = 0.057), higher high-frequency (+ 3.3 nu; p = 0.050) and a reduced low- to high-frequency ratio (− 0.08; p = 0.040). With adjustment for heart rate, these differences disappeared, except for the reduced low-frequency power in the R group (− 4.67 nu; p = 0.02). Analyses confined to 39 R and 47 E patients with HRV measurements at all visits or based on autoregressive modelling were confirmatory.

Conclusion

In native black African patients, antihypertensive drugs modulate HRV, an index of autonomous nervous tone. However, these effects were mediated by changes in heart rate except for low-frequency variability, which was reduced on beta blockade independent of heart rate.

High population frequencies of APOL1 risk variants are associated with increased prevalence of non-diabetic chronic kidney disease in the Igbo people from south-eastern Nigeria

BACKGROUND

Continental Africa is facing an epidemic of chronic kidney disease (CKD). APOL1 risk variants have been shown to be strongly associated with an increased risk for non-diabetic kidney disease including HIV nephropathy, primary non-monogenic focal and segmental glomerulosclerosis, and hypertension-attributed nephropathy among African ancestry populations in the USA. The world's highest frequencies of APOL1 risk alleles have been reported in West African nations, overlapping regions with a high incidence of CKD and hypertension. One such region is south-eastern Nigeria, and therefore we sought to quantify the association of APOL1 risk alleles with CKD in this region.

METHODS

APOL1 risk variants were genotyped in a case-control sample set consisting of non-diabetic, CKD patients (n = 44) and control individuals (n = 43) from Enugu and Abakaliki, Nigeria.

RESULTS

We found a high frequency of two APOL1 risk alleles in the general population of Igbo people of south-eastern Nigeria (23.3%). The two APOL1 risk allele frequency in the CKD patient group was 66%. Logistic regression analysis under a recessive inheritance model showed a strong and significant association of APOL1 two-risk alleles with CKD, yielding an odds ratio of 6.4 (unadjusted p = 1.2E-4); following correction for age, gender, HIV and BMI, the odds ratio was 4.8 (adjusted p = 5.1E-03).

CONCLUSION

APOL1 risk variants are common in the Igbo population of south-eastern Nigeria, and are also highly associated with non-diabetic CKD in this area. APOL1 may explain the increased prevalence of CKD in this region.

Progress report on the first sub-Saharan Africa trial of newer versus older antihypertensive drugs in native black patients

BACKGROUND

The epidemic surge in hypertension in sub-Saharan Africa is not matched by clinical trials of antihypertensive agents in Black patients recruited in this area of the world. We mounted the Newer versus Older Antihypertensive agents in African Hypertensive patients (NOAAH) trial to compare, in native African patients, a single-pill combination of newer drugs, not involving a diuretic, with a combination of older drugs including a diuretic.

METHODS

Patients aged 30 to 69 years with uncomplicated hypertension (140 to 179/90 to 109 mmHg) and ≤2 associated risk factors are eligible. After a four week run-in period off treatment, 180 patients have to be randomized to once daily bisoprolol/hydrochlorothiazide 5/6.25 mg (R) or amlodipine/valsartan 5/160 mg (E). To attain blood pressure <140/<90 mmHg during six months, the doses of bisoprolol and amlodipine should be increased to 10 mg/day with the possible addition of up to 2 g/day α-methyldopa.

RESULTS

At the time of writing of this progress report, of 206 patients enrolled in the run-in period, 140 had been randomized. At randomization, the R and E groups were similar (P ≥ 0.11) with respect to mean age (50.7 years), body mass index (28.2 kg/m(2)), blood pressure (153.9/91.5 mmHg) and the proportions of women (53.6%) and treatment naïve patients (72.7%). After randomization, in the R and E groups combined, blood pressure dropped by 18.2/10.1 mmHg, 19.4/11.2 mmHg, 22.4/12.2 mmHg and 25.8/15.2 mmHg at weeks two (n = 122), four (n = 109), eight (n = 57), and 12 (n = 49), respectively. The control rate was >65% already at two weeks. At 12 weeks, 12 patients (24.5%) had progressed to the higher dose of R or E and/or had α-methyldopa added. Cohort analyses of 49 patients up to 12 weeks were confirmatory. Only two patients dropped out of the study.

CONCLUSIONS

NOAAH (NCT01030458) demonstrated that blood pressure control can be achieved fast in Black patients born and living in Africa with a simple regimen consisting of a single-pill combination of two antihypertensive agents. NOAAH proves that randomized clinical trials of cardiovascular drugs in the indigenous populations of sub-Saharan Africa are feasible.

Left ventricular diastolic function in a predialysis patient population

BACKGROUND

Diastolic dysfunction is common in chronic kidney disease (CKD) accounting for 40%-66% of cardiovascular complications.

OBJECTIVE

To determine the prevalence of and factors associated with left ventricular diastolic dysfunction (LVDD) in adult Nigerians with CKD at presentation and to compare findings with those of hypertensive patients with normal renal function.

METHODS

Eighty-six consecutive patients with CKD were studied, comprising 43 hypertensives and 43 age- and sex-matched healthy subjects as controls. Clinical, laboratory, and echocardiographic variables were measured.

RESULTS

Left ventricular diastolic dysfunction was present in 62.8% of CKD patients, 79.1% of hypertensive patients and 25.6% of normal controls (p<0.001). There was a positive correlation between left ventricular diastolic function (LVDF) and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), severity of SBP, severity of DBP in CKD patients but not in hypertensive patients. There was a negative correlation between LVDF and age in CKD patients and hypertensive patients. Linear multiple regression analysis showed age as the only predictor of LVDD.

CONCLUSION

There is a high prevalence of diastolic dysfunction in CKD patients at first presentation to a nephrologist in Nigeria.

High prevalence and low awareness of hypertension in a market population in enugu, Nigeria

Background. A community-based study put the prevalence of hypertension in Nigeria at 32.8%. Market workers in Nigeria lead sedentary life style and often depend on salt-laden fast food while at work. Method. An unselected population of market workers were screened for hypertension and its risk factors by a pretested, structured questionnaire, clinical examination, and laboratory investigation. Hypertension was defined as BP ≥ 140 and/or ≥ 90 mmHg or being on drug therapy. Results. Forty-two percent of the screened population were hypertensive. Of this number, 70.6% did not know they were hypertensive before the screening. More males than females (P = .022) were hypertensive. Prevalence of hypertension increased with age from 5.4% in the age group <20 years to 80% in the age group ≥70 years. Conclusion. The prevalence of hypertension in market workers in this study was 42%, and the majority of them were unaware of their disease.

The enormity of chronic kidney disease in Nigeria: the situation in a teaching hospital in South-East Nigeria

Background. The magnitude of the problem of chronic kidney disease (CKD) is enormous, and the prevalence keeps rising. To highlight the burden of CKD in developing countries, the authors looked at end-stage renal disease (ESRD) patients seen at the University of Nigeria Teaching Hospital (UNTH), Enugu, South-East Nigeria. Method. ESRD patients seen from 01/05/1990 to 31/12/2003 were recruited. Records from A&E Department, medical-out-patients, wards and dialysis unit were used. Results. A total of 1001 male versus 537 female patients were reviewed. About 593 male versus 315 female patients had haemodialysis. The mean age was 42.55 +/- 15.43 years and 86.5% were <60 years. Primary renal disease could not be determined in 51.6% while hypertension and glomerulonephritis accounted for -17.2% and 14.6%, respectively. Death from renal causes constituted 22.03% of medical deaths. Conclusion. The prognosis for CKD patients in Nigeria is abysmal. Only few patients had renal-replacement-therapy (RRT). The prohibitive cost precludes many patients. This underscores the need for preventive measures to reduce the impact of CKD in the society.

Respiratory symptoms and ventilatory function tests in Nigerians with HIV infection

BACKGROUND

The impact of the human immunodeficiency virus (HIV) infection on the respiratory system of Africans has been little studied. This study aimed to determine the pattern of respiratory symptoms and ventilatory functions in HIV infected Nigerians.

METHODS

In this cross sectional study, Respiratory symptoms frequency, Forced vital capacity (FVC), Forced expiratory volume in one second (FEV(1)), FEV(1)/FVC ratio, Forced expiratory flow between 25% and 75% of FVC, were determined in 100 HIV positive subjects and compared with values in 100 HIV negative controls.

RESULTS

HIV positive patients had significantly more respiratory symptoms and lower ventilatory function tests values compared to the matched controls (p<0.05). HIV patients with at least one respiratory symptom and those with CD4 count less than 200 cells/µl had lower ventilatory function values than their counterparts. 32% of the HIV patients had restrictive ventilatory functional impairment. (p<0.05). Using regression analysis, factors like HIV status, CD4 count and presence of respiratory symptoms were found to be associated with impairment in ventilatory functions.

CONCLUSIONS

HIV infected patients had more frequent respiratory symptoms and lower ventilatory function values. Further lung function studies and CT scanning in HIV positive patients especially in those with respiratory symptoms are indicated.

A community-based study of hypertension and cardio-metabolic syndrome in semi-urban and rural communities in Nigeria

Background

The prevalence of cardio-metabolic syndrome (CMS) is increasing worldwide. In people of African descent, there is higher prevalence of hypertension and complications than other races. Bearing in mind these facts, we looked at the CMS in the general population and the population with hypertension. Using the new International Diabetes Federation (IDF) definitions of CMS, we studied its prevalence in semi-urban and rural communities in South-east Nigeria in relation to hypertension.

Method

This is a cross sectional population based study involving 1458 adults aged from 25 to 64 years. Diagnosis of CMS was based on the new IDF criteria using the anthropometric measurements for Europids as there is none yet for blacks. Hypertension was defined according to the WHO/ISH criteria.

Results

The overall prevalence of CMS was 18.0% in the semi-urban community as against 10.0% in the rural community increasing to 34.7% and 24.7% respectively in the population with hypertension. The prevalence of co-morbidities - hyperglycaemia, abdominal obesity, and hypertriglceridaemia were 13.9%, 41.1% and 23.9% while in the hypertensive populations they were 21.2%, 55.0% and 31.3% in the general population in both communities combined. Except for low HDL cholesterol, every other co-morbidity was higher in hypertensive population than the general population.

Conclusion

The high prevalence of CMS in the semi-urban population especially for the population with hypertension underscores the double burden of disease in developing countries. The lesson is while infections and infestations are being tackled in these countries the non-communicable diseases should not be neglected.

Left ventricular hypertrophy in African Black patients with chronic renal failure at first evaluation

OBJECTIVE

Chronic kidney disease (CKD) is a major cause of cardiovascular morbidity and mortality all over the world. The combined effect of volume and pressure overload seen in patients with CKD is the primary cause of left ventricular hypertrophy (LVH). Though it accounts for a significant proportion of patients dying in hospitals in Nigeria, information on CKD in African Blacks is lacking. This study evaluates the prevalence of LVH and factors affecting it in pre-dialysis patients by using echocardiography.

DESIGN, SETTING AND PATIENTS

One hundred consecutive patients with CKD who were attending the medical outpatient and renal clinics of University of Nigeria Teaching Hospital, Enugu, who satisfied the inclusion criteria were screened for the study. Eighty-eight patients completed the study. Forty-five age- and sex-matched subjects were selected as controls. Clinical and laboratory parameters and echocardiographic indices were measured.

RESULTS

Left ventricular hypertrophy (LVH), defined in absolute terms as left ventricular mass index >134 g/m2 in men and >110 g/m2 in women was present in 95.5% of patients and 6.7% of controls. The most prevalent type of LVH was eccentric hypertrophy, which was found in 54.6%, while concentric was seen in 40.9%. Hypertension was present in 85.2% of the patients. The predominant causes of CKD were chronic glomerulonephritis (43.2%), hypertension (25%), and diabetes mellitus (14.8%). All the patients studied had advanced CKD, either stage 4 or 5 of the Kidney Disease Outcome Quality Initiative classification of CKD. Stepwise method of multiple linear regressions identified mean arterial pressure (32%), hemoglobin concentration (22%), male sex (17%), and creatinine clearance (24%) as predictors of LVH in CKD.

CONCLUSION

This study showed a strong association between CKD and LVH in patients in developing countries at the time of first evaluation by a nephrologist. It demonstrated a high prevalence of LVH in patients at first evaluation. The patients were often anemic and had severe hypertension even at first presentation. Early detection and treatment of causes of CKD should be pursued aggressively at the primary prevention level, as has been advocated by the International Society of Nephrology to reduce the effects of CKD and its attendant complications in the society.

Diabetic Nephropathy: A review of the Past, Present and Future Perspectives - Part 2

Diabetic renal disease is a serious problem resulting from microvascular complications in both type 1 and type 2 diabetes mellitus. There is increased mortality from cardiovascular causes in patients with diabetic nephropathy. However, in spite of plethora of studies in recent years on the possible pathogenetic mechanisms involved in diabetic nephropathy, the exact role of each individual mechanism is still inconclusive. Diabetic nephropathy is reviewed in two parts, the first part deals with historical background, pathophysiology and pathogenesis including the roles of chronic hyperglycaemia, renin-angiotensin system and several mediators in the renal changes in diabetes mellitus. While the second part reviews the treatment as well as current theories in treatment and possible intervention strategies of the future. Key words: diabetic nephropathy, microalbuminuria, pathogenesis, renin-angiotensin system, pathophysiology, treatment.

Diabetic Nephropathy: A review of the Past, Present and Future Perspectives - Part I

Diabetic renal disease is a serious problem resulting from microvascular complications in both type 1 and type 2 diabetes mellitus. There is increased mortality from cardiovascular causes in patients with diabetic nephropathy. However, in spite of plethora of studies in recent years on the possible pathogenetic mechanisms involved in diabetic nephropathy, the exact role of each individual mechanism is still inconclusive. Diabetic nephropathy is reviewed in two parts, the first part deals with historical background, pathophysiology and pathogenesis including the roles of chronic hyperglycaemia, renin-angiotensin system and several mediators in the renal changes in diabetes mellitus. While the second part reviews the treatment as well as current theories in treatment and possible intervention strategies of the future. Key words: diabetic nephropathy, microalbuminuria, pathogenesis, renin-angiotensin system, pathophysiology, treatment.

A case of fractured internal jugular catheter

We report a case of fractured internal jugular catheter, a rare but life threatening complication of the use of intravascular catheter in a 73 year-old man. He had an internal jugular catheter in-situ for nine months, much longer than the manufacturer's recommended duration.