|Year : 2015 | Volume
| Issue : 3 | Page : 137-142
Screening for risk factors of chronic kidney disease in a community in Niger Delta Nigeria
Umezurike Hughes Okafor1, S Ahmed2, EI Unuigbe2
1 Department of Medicine, ESUT Teaching Hospital, Parklane, Enugu, Nigeria
2 Department of Medicine, University of Benin Teaching Hospital, Benin City, Nigeria
|Date of Web Publication||28-May-2015|
Umezurike Hughes Okafor
Department of Medicine, ESUT Teaching Hospital, Parklane, Enugu
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Chronic kidney disease (CKD) is associated with many traditional and nontraditional risk factors. Screening for these risk factors has been associated with appropriate interventions and preventive measures in the management of CKD. The aims and objective of this study are to screen for risk factors of CKD in a Niger Delta community in Nigeria.
Subjects and Methods: This was a cross-sectional study. The study location was Ido, a Niger Delta community in Rivers State. All subjects aged 18 years and above who gave consent were recruited for the study. Their bio data, relevant medical history, clinical and laboratory parameters were documented. The obtained data were analyzed with SPSS versions 17.0.
Results: A total of 105 persons participated in the study. The age range was 18-86 years, 50.5% were above 50 years. Females were 75.0%, 66.7% had either primary or no education, 14.6% were retiree and 40.4% were traders. 14.1% were known hypertensive, and 39.4% had elevated blood pressure. 6.1% were known diabetic and 6.1% had random blood sugar of 200 mg/dl and above. 27.2% of subjects were obese. About 10.5% and 27.8% had a history of significant intake of tobacco and alcohol respectively. Total serum cholesterol was higher than 200 mg/dl in 51.5%. None of the participants had past or family history of kidney disease.
Conclusion: The prevalence of risk factors for CKD in the Niger Delta community is high.
| Abstract in French|| |
Context: Insuffisance rénale chronique (IRC) est associée à plusieurs facteurs de risque traditionnels et non traditionnels. Dépistage de ces facteurs de risque a été associée à des interventions appropriées et de mesures de prévention dans la gestion de CKD. Les buts et l'objectif de cette étude sont à dépister les facteurs de risque de CKD dans une communauté du Delta du Niger au Nigeria.
Sujets et Méthodes: il s'agissait d'une étude transversale. L'emplacement de l'étude était Ido, une communauté du Delta du Niger dans l'état de Rivers. Tous les sujets âgés de 18 ans et au-dessus qui a donné le consentement ont été recrutés pour l'étude. Leurs données de bio, les antécédents médicaux, cliniques et des paramètres de laboratoire ont été recensés. Les données obtenues ont été analysées avec SPSS versions 17,0.
Résultats: Un total de 105 personnes ont participé à l'étude. La tranche d'âge était de 18 - 86 ans, 50,5 % avaient plus de 50 ans. Les femmes étaient 75,0 %, 66,7 % avaient soit primaire, soit aucune éducation, 14,6 % étaient à la retraite et 40,4 % étaient des commerçants. 14,1 % étaient connus des hypertendus et 39,4 % ont élevé la tension artérielle. 6,1 % étaient connus des diabétiques et 6,1 % avaient une glycémie aléatoire de 200 mg/dl et plus. 27,2 % étaient obèses. Environ 10,5 % et 27,8 % qui ont une histoire de l'apport significatif de tabac et d'alcool. Taux de cholestérol sérique total était supérieur à 200 mg/dl à 51,5 %. Aucun des participants avaient des antécédents familiaux ou passé de néphropathie.
Conclusion: La prévalence des facteurs de risque de CKD dans la communauté du Delta du Niger est élevée.
Mots-clés: Insuffisance rénale chroniqueprévalence, risque, dépistage
Keywords: Chronic kidney disease, prevalence, risk, screening
|How to cite this article:|
Okafor UH, Ahmed S, Unuigbe E I. Screening for risk factors of chronic kidney disease in a community in Niger Delta Nigeria. Ann Afr Med 2015;14:137-42
| Introduction|| |
The magnitude of the problem of chronic kidney disease (CKD) is enormous, and the prevalence of kidney failure is rising. Currently, CKD is emerging as a worldwide public health problem. Globally, they represent the 12 th cause of death and 17 th cause of disability  according to World Health Organization (WHO) data. The global increase in the prevalence of CKD and its disproportionate burden on economically developing countries is being driven by an increase in the prevalence of the main risk factors for CKD, namely, diabetes mellitus, hypertension, obesity, increasing growth, and aging of the population. ,,
The asymptomatic nature of CKD makes explicit screening strategies for individuals at risk as the only means of early detection. This will allow more time for interventions to alter the natural history of the disease by delaying or preventing kidney disease progression and its complications. Patient awareness of CKD remains low. Detection of individuals at risk and utilization of CKD tests for these patients at risk and interpretation of those tests to detect CKD by primary care physicians remain suboptimal. Diabetes mellitus, hypertension, and age 60 years or above are the primary CKD screening target conditions, based on assessments representative of the general populations. However, cardiovascular disease, family history of CKD, ethnic and racial peculiarities are also important predictors of CKD risk. 
Community surveys have shown that the number of people with end-stage kidney disease is just the tip of the "CKD iceberg."  The preventive strategies to stem the tide of CKD should involve educating the population on how to prevent renal disease; identifying those at risk of developing CKD; raising the awareness of the general public, policy makers, and health care workers; modifying the lifestyle of susceptible individuals; detecting early stage of CKD; arresting or hindering the progression of disease; and creating facilities for global assistance. ,,
The past decade has seen a growing awareness of the problem of undiagnosed CKD and the implications for the provision of renal replacement therapy (RRT). Substantial success has been achieved in promoting improved screening for and treatment of CKD to improve outcomes and reduce demand for RRT. These important aims have highlighted the twin problems of how to identify subjects for screening and target intervention to those with CKD most likely to result in end-stage renal disease (ESRD). Cost-effectiveness studies indicate that screening whole populations is not a viable means of identifying high-risk individuals, thus targeted screening is therefore required.
In most developing nations including Nigeria, ESRD constitutes a death sentence as RRT is often unavailable or unaffordable.  At the individual level, CKD affects all facets of health: Physical (increased burden of cardiovascular disease morbidity and mortality) and social (low quality of life, decreased productivity and job losses, family pressures, and mental disorders). Thus, preventive programs for CKD in these developing countries are imperative. These preventive programs are targeted on the general population with special attention on those at risk of developing CKD. These at risk population are detected by screening for the risk factors incriminated in the development of CKD in the populace.
The aim of this study is to screen for risk factors for the development of CKD in a Niger Delta community in Nigeria.
| Subjects and Methods|| |
Study location and design
This was a cross-sectional study. The study location was Ido, a rural community in Asari Toru Local government Area of Rivers state, Nigeria. This is situated in the Niger Delta area of Nigeria with a population of about 1900 inhabitants. This is an agrarian and swampy environment surrounded by creeks and evidence of environmental degradation resulting from past oil exploration. The inhabitants are mainly indigene of Kalabari (Ijaw) extraction, and they speak Kalabari (Ijaw) and pidgin English.
The study population was adult aged 18 years and above who gave consent to the study. Approval for the study was obtained from the council of chiefs headed by the paramount ruler of the community.
The information for the study was disseminated in the community through the churches and the town crier. The venue of the screening was the community town hall. The details of this study were explained, and informed consent obtained from each subject. There was a session of health education on CKD, delivered by one of the investigators.
The study was on consecutive subject aged 18 years and above who are qualified and gave informed consent to the study.
Data and specimen collection
The bio data and medical details of each subject were documented. Measurement of weight, height and blood pressure (BP) were obtained using appropriate and standard measuring apparatus and technique. The body mass index (BMI) was calculated using weight (kg)/height (m 2 ).
Blood sample was collected from each subject, and the following were assessed-random blood sugar and lipid profile using appropriate investigative technique.
The following are defined as significant:
- Exercise - At least thrice weekly exercise not <30 min/day
- Smoking - Smoking of ≥5 pack years
- Alcohol - Ingesting at least 21 and 14 units of alcohol for men and female respectively
- Cholesterol - Total cholesterol ≥ 200 mg/dl
- Low density lipoprotein (LDL) ≥ 100 mg/dl
- High density lipoprotein (HDL) ≤ 40 mg/dl
- Obesity - BMI ≥30
- Elevated BP - systolic BP ≥140 and/or diastolic BP ≥ 90 mmHg
- Elevated blood glucose - random blood glucose ≥ 200 mg/dl.
The data obtained were entered into spreadsheet and analyzed using SPSS versions 17 (IBM corporation NY, USA). Data were presented as frequencies and means ± standard deviation. P < 0.05 was considered as significant.
| Results|| |
A total of 105 subjects participated in the screening. However 99 (94.3%) of them had complete data.
The age range of the subjects was 18-86 years; the median age was 52 years; the mean age was 50.7 ± 18.6 years and 50.5% were aged above 50 years. There were 74 (75%) females and 25 (25%) males, with a male to female ratio of 1:3.
About two-third (66.7%) of the studied population had either none or only basic primary education, 72% of them were aged 50 years and above, however only 6.1% of the studied population had tertiary education. About 40.4% of the subjects were petty traders, 14.6% were retirees, and about 40% were either junior public servants, applicants, students or subsistence fishermen. All the retirees, the fishermen, were 50 years and above.
The mean systolic BP was 135.4 ± 32.6 mmHg and mean diastolic BP was 79.4 ± 17.6 mmHg. Fourteen (14.1%) and 30 (30.3%) participants had past and family history of hypertension respectively, 72.1% and 33.4% of them respectively were 50 years and above; however 41 (41.4%) participants had their BP elevated, 33 (80.5%) were 50 years and above. Only 5 (16.7%) and 1 (3.3%) of participants with hypertension were on regular medications and follow-up in the hospital. The stages of hypertension using isolated systolic hypertension/WHO classification are shown in [Table 1].
Six (6.1%) had been diagnosed with diabetes mellitus, all were type 2 diabetes mellitus, 2 (33.3%) were younger than 50 years. And only 1 (16.7%) of them was adherent to medication (oral hypoglycemic agent) and regular to clinic follow-up. Fourteen (14.1%) had family history of diabetes mellitus. Six (6.1%) participants, including 4 (66.7%) with previously diagnosed diabetes mellitus had random blood sugar ≥200 mg/dl.
The mean BMI was 26.3 ± 6.5. Twenty-four (24.2%) were overweight and 27 (27.2%) were obese. Eighteen (18.1%), 6 (6.1) and 3 (3.0%) had mild, moderate and severe obesity, respectively. However, 41.7% and 29.6% of those overweight and obese respectively were either 50 years or older.
A total of 11 (11.1%) had history of smoking, 7 (63.6%) of them were 50 years and above, 7 (7.1%) had smoked for at least 10 years, however 3 (3.1%) smoked 5 pack-years and above. Twenty-six (26.1%) participant had a significant history of alcohol ingestion.
Fifty-one (51.5%) participants total cholesterol (TC) 200 mg/dl and above, 52.9% of them were younger than 50 years. Fifty two (52.5%) participants had LDL 100 mg/dl and above, 26 (26.3) had HDL level below 40 mg/dl.
Forty-six (46.5%) participants were involved in some form of exercise, 24 (24.2%) participants, most of them (75%) younger than 50 years had significant and regular exercise either regulated or not regulated.
There was no participant with family or previous history of kidney disease.
| Discussion|| |
Kidney function has been noted to have an inverse relationship with age, and has been reported to decrease by 0.5 ml/min/1.73 m 2 annually.  This could have resulted from recurrent mild kidney insults that subsequently compromises the integrity of the kidney functions in life leading to CKD. However, little is known about how the clinical implications of CKD vary with age. In this study majority of the participants were either in the middle or elderly age group. This further revealed that most of the risk factors for development of CKD were more in the older population. The propensity of this aging population in this rural community could be attributed to urban migration of the younger age group in search of more lucrative job. This population is either illiterates or semi illiterate and their occupations were not lucrative. This is comparative to sociodemographic pattern reported in most rural communities in Nigeria.  This pattern has been reported to increase the risk for development and propagation of CKD.  This entails by virtue of this sociodemographic pattern, this community is at a high-risk of CKD. This contrasts with the sociodemographic pattern of most developed countries of USA and Europe which could explain the reported lower prevalence of CKD in these populations. ,,
Hypertension has been documented as a common risk factor in the development of CKD globally. In Nigeria, it ranked with chronic glomerulonephritis as the most commonly implicated among the causes of CKD.  About 40% of the subjects in this study had elevated BP, this was high when compared with reports of various studies in other Niger Delta communities in the country. ,, However, Akpa et al.  reported a similar prevalence rate (40.8%) in a survey of a Niger Delta community in Rivers state. This high prevalence of hypertension could be multifactorial in this community including poor socioeconomic status, high salt intake especially from their water source which is predominant salty water, nonideal weight as over 50% were either overweight or obese and lack of exercise as <54% of the population exercise suboptimally or does not exercise at all. Also, genetics may have contributed significantly to this degree of hypertension as about 30% had a relative with a history of hypertension. Furthermore, awareness of hypertension is poor, as only 14% of were aware they had elevated BP. This is consistent with other study on hypertension and other noncommunicable diseases. ,,,,,,,,,
Diabetes mellitus is a leading cause of CKD globally. It is the 3 rd most common cause of CKD in Nigeria accounting for about a fifth of patients with CKD.  Also, about 23% of the diabetic population subsequently develops CKD, and this is, usually, influenced by the duration of DM, degree of glycemic control, comorbid state and genetics.  In Nigeria, the national prevalence of diabetes mellitus had been reported in 1992 to be 2.7%,  which contrast the prevalence rate of 8.1% in this study. This higher prevalence may be related to increasing incidence and prevalence of diabetes mellitus globally, especially in the developing countries. ,,
Obesity including overweight has been implicated as a possible risk factor for development and propagation of CKD. The mechanism of renal impairment resulting from obesity includes glomelurar hyperfilteration/sclerosis, glomerulopathy from lipotoxicity, oxidative stress and inflammation, physical compression from visceral fat, and renal injuries from calcium oxalate and urate stone formation. Furthermore, obesity has also been incriminated as risk factors in other clinical conditions, including hypertension, diabetes mellitus and hyperlipidemia that predispose patients to the development of kidney disease.
There is a global epidemic of obesity with remarkable increasing prevalence in the developed countries. Hitherto the prevalence of obesity in the developing countries including Nigeria was low. However, this is changing with increasing urbanization. These have been attributed to various epidemiological and demographic changes, including rural to urban drift, changes in lifestyle and socioeconomic factors. This is reflected in the result of this study that found 24% and 27% of the participants been overweight and obese respectively which is consistent with a similar study by Amira et al.  in Western Nigeria that reported a prevalence of 32% and 22% respectively. However, a lower prevalence of 17.2% and 4.5% respectively was reported in a community survey in Northern Nigeria,  this could be attributed to genetics, cultural and socioeconomic factors. Thus, the studied population is at a higher-risk of developing kidney disease resulting from obesity.
Tobacco and alcohol
The association between smoking and kidney damage was noted by earlier investigators in 19 th and 20 th centuries.  However, the importance of smoking in precipitation and propagation of kidney disease was recently validated. ,, Smoking has a deleterious effect on both normal and diseased kidneys including transplanted kidneys. The effect of smoking on the kidney has a positive correlation with duration and quantity of tobacco use. Passive smokers had also been noted to be at a greater risk of developing kidney disease than nonexposed nonsmokers. ,, The mechanism of their effect had been reported to include intrarenal vasoconstriction, release of oxidative stress and proinflammatory cytokines and hypertension. These had led to increased intrglomerular hypertension, vascular endothelial damage and interstitial fibrosis resulting in glomerulosclerosis and tubular dysfunction/atrophy. 
Eleven (11.1%) participants in this study were smokers, and about 60% and 30% of them had smoked for about 10 years and 5 pack years respectively. This prevalence is higher than the national prevalence of tobacco use as reported by the World Bank and the global adult tobacco survey in Nigeria.  This high prevalence of smoking in this population could be attributed to some cultural practices that do not discourage tobacco use, thus they are at higher-risk of developing and worsening of kidney disease attributable to smoking.
Alcohol has been reported to potentially have profound negative effects on the kidneys and its function. It has been associated with glomerular and tubular changes including interference with the fluid, electrolyte, acid and base homeostatic functions of the kidneys. However, most reports on the relationship between alcohol and the kidneys have been on animal studies.
Significant alcohol consumption occurs when 21 and 14 units of alcohol are exceeded weekly in males and females respectively. Thus in this study 26.1% of the population had significant alcohol consumption which is high when compared to the report on African region of global status report on alcohol.  However, previous studies in Niger Delta region of Nigeria had reported a similar high prevalence of significant/hazardous alcohol consumption in the region.  This could be attributed to the cultural practices of the region that encourage and include alcohol consumption in some of the traditional rites. This will pose a greater risk to development of alcohol related diseases including kidney dysfunction.
Various experimental and clinical studies have suggested a correlation between the progression of renal disease and dyslipidemia. High cholesterol and triglyceride plasma levels have been demonstrated to be independent risk factors for progression of renal disease in humans. The underlying mechanisms for the relationship between lipid levels and progression of renal disease are not yet fully understood. However, there are data that oxidative stress and insulin resistance may mediate the lipid-induced renal damage leading to various glomerular and tubular injuries.
Various guideline recommended desirable lipid levels of total cholesterol of <200 mg/dl, low density cholesterol of <100 mg/dl, high density cholesterol of 40 mg/dl or more, triglyceride of <150 mg/dl. However, there are adjustment depending on the prevailing co-morbidities, sex and presence of other cardiovascular risk factors. This study revealed that more than 50% of the participants had undesirable levels of total cholesterol and LDL, and about 26% had undesirable level of HDL. Various studies have reported similar high prevalence of undesirable levels of lipids among the northern, eastern and western Nigerian populations.  This could be attributed to our dietary constituent that contains high saturated fat. The population studied is at a higher-risk of developing lipid-related disorders including kidney disease.
Family history of kidney disease , lack of exercise, ingestion of herbs and across the counter medication including some pain killers, antibiotics and anti-inflammatory medications has been reported to increase the risk of CKD. None of the participant in this study had family history of kidney disease, and significant exercise was documented in only a quarter of the participants.
| Conclusion and Recommendation|| |
The prevalence of risk factors to the development of CKD in this community is high. There is a need for increased awareness on the presence of these risk factors, and its prevention.
The limitation of this study is the small sample size and thus there is a need for a wider and larger scale study in the Niger Delta region of Nigeria on the assessment of the risk factors of CKD.
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