The global public health importance of renal dysfunction is increasing due to a host of reasons including an increasing number of patients progressing to end-stage renal disease (ESRD), high costs to public health systems, and its associated morbidity and mortality, particularly those associated with cardiovascular disease [
Asutifi-South District is one of the administrative districts in the Brong Ahafo Region, Ghana. The District was carved out from the then Asutifi District in July 2012 with Hwidiem as the district capital. The dominant vocation of the district is agriculture with 71.8% of households engaged in activities such as crop farming, animal rearing, and fish farming. St. Elizabeth hospital is a Catholic Health delivery facility in the Goaso Diocese. It is located in the Asutifi-South District in the Brong Ahafo Region of Ghana, providing healthcare to all its neighboring communities. It started as a Leprosy camp in 1955 and evolved over the years into a District Hospital. The hospital provides the following services: curative, preventive and promotive, rehabilitative, diagnostic, and special programs [
A hospital-based, descriptive cross-sectional study was conducted between January and March 2018 at the Diabetes and Hypertension Clinic of St. Elizabeth Hospital in the Asutifi-South District of the Brong Ahafo Region.
The study population consisted of male and female hypertensive participants who were of consent age (18 years and above) in the Asutifi-South District. The hypertensive registrants were conveniently and purposively sampled at the Diabetes and Hypertensive Clinic of the hospital.
Using the average monthly attendance of hypertensive patients for three months (133), a total study population of 399 was generated for the three months study duration. Raosoft online sample size calculator (http://www.raosoft.com/samplesize.html) was used, and a recommended minimum sample of 197 participants was calculated at 95% confidence level, 5% margin of error, and a response distribution of 50%.
A self-reported semistructured questionnaire was administered to obtain primary data from consenting adult clients. Sociodemographic information captured included age, gender, marital status, educational level, and occupation. Diabetes status and therapeutic variables including type of antihypertensive medication used and the duration on medication were ascertained using patient folders.
Blood pressure was measured in the nondominant arm using fully-automated blood pressure monitor (OMRON Healthcare, Intelli-Sense BP785, HEM-7222, USA) in sitting position after resting for 3–5 minutes. A single qualified nurse recorded the average of two consecutive blood pressure readings taken on different occasions. Weight of participants was measured in light clothing, without shoes, and standing upright using a digital weighing scale (Health O Meter, USA) to the nearest 0.1 kg.
Venous blood sample was drawn from the antecubital veins of the arm of which three (3) milliliters was dispensed into a vacutainer® serum separator tube using the closed vacutainer system. The sample in the serum separator tube was allowed to clot, centrifuged at 2500 revolutions per minute (rpm) for 5 minutes at room temperature to obtain serum. The serum was stored at -20°C at the St. Elizabeth Hospital until analysis. Serum samples were then transported on ice to the St. John of God Hospital Laboratory, Duayaw-Nkwanta where it was thawed and creatinine was measured on a Random Access Fully Automated Dirui CS – T240 Chemistry Analyzer, China. The methods used to assay creatinine were predetermined by the reagent manufacturer (Dirui Industries Co., Ltd, China). The quality of the results was ensured by running daily quality control checks and regular calibration of the instruments used.
The eGFR was calculated from serum creatinine values using the following predictive equations: Cockroft-Gault (CG) [ Four-Variable Modification of Diet in Renal Disease (4v-MDRD) [ Chronic Kidney Disease Epidemiology collaboration- CKD-EPI [
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Female | ≤62 (≤0.7) | |
Female | >62 (>0.7) | |
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Male | ≤80 (≤0.9) | |
Male | >80 (>0.9) | |
The calculated GFR was used to classify study participants into various categories of renal function according to the Kidney Disease Improvement Global Outcome (KDIGO) Criteria [
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G1 | Normal or high | ≥90 |
G2 | Mildly decreased | 60 to 89 |
G3 | Mildly to moderately decreased | 30 to 59 |
G4 | Severely decreased | 15 to 29 |
G5 | Kidney failure | <15 |
Normality of all continuous variables was tested. Continuous variables were expressed as their mean ± standard deviation. Gender variation in the prevalence of kidney function was performed using unpaired t-tests, chi-square (
Ethical approval was obtained from the Research Ethics Committee of the University of Health and Allied Sciences, Ho, Ghana
Out of the two hundred (200) participants recruited into this study, 48 (24.00%) were males and 152 (76.00%) were females. The average age of the total population was 61 ± 10 years. Sixty-seven (33.50%) of the study participants were both diabetic and hypertensive while 133 (66.50%) were hypertensive only. Majority of the study population were married [127 (63.5%)], with only 22.00% attaining secondary level education or higher at the time of this study. Majority of the study participants were gainfully employed 161 (80.50%). The average weight of the study participants was 64.23 ± 13.2 kg with the difference in weight between participants presenting with both diabetes and hypertension and those suffering from only hypertension observed to be statistically comparable (see Table
Socio-demographic characteristic of the population under study stratified by disease status.
Parameter | Total | Diabetic and Hypertensive all together | Hypertensive only |
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Total Respondents | 200 (100) | 67 (33.5) | 133 (66.5) |
Age (years) | 61 ± 10 | 62 ± 9 | 61 ± 10 |
Weight (kg) | 64.23 ± 13.2 | 63.10 ± 13.8 | 64.80 ± 13.8 |
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Male | 48 (24.0) | 12 (17.9) | 36 (27.1) |
Female | 152 (76.0) | 55 (82.1) | 97 (72.9) |
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Single | 3 (1.5) | 1 (1.5) | 2 (1.5) |
Married | 127 (63.5) | 36 (53.7) | 91 (68.4) |
Divorced | 9 (4.5) | 5 (7.5) | 4 (3.0) |
Widowed | 58 (29.0) | 24 (35.8) | 34 (25.6) |
Separated | 3 (1.5) | 1 (1.5) | 2 (1.5) |
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None | 86 (43.0) | 33 (49.3) | 53 (39.8) |
Basic | 70 (35.0) | 21 (31.3) | 49 (36.8) |
Secondary | 21 (10.5) | 9 (13.4) | 12 (9.0) |
Tertiary | 23 (11.5) | 4 (6.0) | 19 (14.3) |
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Unemployed | 36 (18.0) | 12 (17.9) | 24 (18.0) |
Employed | 161 (80.5) | 54 (80.6) | 107 (80.5) |
On Pension | 3 (1.5) | 1 (1.5) | 2 (1.5) |
Data is presented as mean ± standard deviation and frequency with percentage in parenthesis.
The prevalence of renal impairment ranged from 9.50% through 10.50 to 25.00% using the 4v-MDRD, CKD-EPI and CG equations respectively. About 50 (22.50%), 19 (8.00%), and 21 (8.50%) of study participants were found to present with mild to severely decreased GFR (G3) using CG, 4v-MDRD, and CKD-EPI, respectively, with less than 3% classified as having severely decreased GFR (G4) while none presented with kidney failure (G5). The prevalence of renal impairment was significantly tilted toward the diabetic and hypertensive group using the CG, 4v-MDRD, and CKD-EPI equations (see Table
Renal dysfunction categorization among study population using KDIGO eGFR Criteria stratified by disease status.
eGFR Category | Total | Diabetic and Hypertensive all together | Hypertensive only | p-value | ||
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CG | G 1 | (≥90) | 73 (36.50) | 22 (32.84) | 51 (38.35) | |
G 2 | (60 to 89) | 77 (38.50) | 25 (37.31) | 52 (39.10) | ||
G 3 | (30 to 59) | 45 (22.50) | 17 (25.37) | 28 (21.05) | ||
G 4 | (15 to 29) | 5 (2.50) | 3 (4.48) | 2 (1.50) | ||
G 5 | (<15) | 0 (0.00) | 0 (0.00) | 0 (0.00) | ||
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4v-MDRD | G 1 | (≥90) | 137 (68.50) | 41 (61.19) | 96 (72.18) | |
G 2 | (60 to 89) | 44 (22.00) | 15 (22.39) | 29 (21.80) | ||
G3 | (30 to 59) | 16 (8.00) | 9 (13.43) | 7 (5.26) | ||
G4 | (15 to 29) | 3 (1.50) | 2 (2.99) | 1 (0.75) | ||
G5 | (<15) | 0 (0.00) | 0 (0.00) | 0 (0.00) | ||
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CKD-EPI | G1 | (≥90) | 130 (65.00) | 40 (59.70) | 90 (67.67) | |
G2 | (60 to 89) | 49 (24.50) | 16 (23.88) | 33 (24.81) | ||
G3 | (30 to 59) | 17 (8.50) | 8 (11.94) | 9 (6.77) | ||
G4 | (15 to 29) | 4 (2.00) | 3 (4.48) | 1 (0.75) | ||
G5 | (<15) | 0 (0.00) | 0 (0.00) | 0 (0.00) | ||
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Data is presented as frequency and percentage in parenthesis. 4v-MDRD – four variable Modification of Diet in Renal Disease, CG – Cockcroft-Gault, CKD-EPI – Chronic Kidney Disease Epidemiology collaboration, eGFR – estimated Glomerular Filtration Rate, CKD – Chronic Kidney Disease, G1-Category one, G2-Category two, G3-Category three, G4-Category four, G5-Category five.
Significant gender variation in renal dysfunction was observed, with a higher prevalence tilted toward the female gender using the CG and 4v-MDRD equations except for CKD-EPI equation where the difference in the percentage scores was statistically comparable. The rate of renal impairment among the male participants ranged from 2.08% to 12.50% as compared to 11.84% to 28.95% among their female counterparts. All the male participants presenting with renal impairment were in G3 category (see Table
Renal dysfunction categorization among study population using KDIGO eGFR Criteria stratified by gender.
eGFR Category | Male | Female | p-value | ||
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CG | G1 | (≥90) | 22 (45.83) | 51 (33.55) | |
G2 | (60 to 89) | 20 (41.67) | 57 (37.50) | ||
G3 | (30 to 59) | 6 (12.50) | 39 (25.66) | ||
G4 | (15 to 29) | 0 (0.00) | 5 (3.29) | ||
G5 | (<15) | 0 (0.00) | 0 (0.00) | ||
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4v-MDRD | G1 | (≥90) | 38 (79.17) | 99 (65.13) | |
G2 | (60 to 89) | 9 (18.75) | 35 (23.03) | ||
G3 | (30 to 59) | 1 (2.08) | 15 (9.87) | ||
G4 | (15 to 29) | 0 (0.00) | 3 (1.97) | ||
G5 | (<15) | 0 (0.00) | 0 (0.00) | ||
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CKD-EPI | G1 | (≥90) | 37 (77.08) | 93 (61.8) | |
G2 | (60 to 89) | 9 (18.75) | 40 (26.32) | ||
G3 | (30 to 59) | 2 (4.17) | 15 (9.87) | ||
G4 | (15 to 29) | 0 (0.00) | 4 (2.63) | ||
G5 | (<15) | 0 (0.00) | 0 (0.00) | ||
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Data is presented as frequency with percentage in parenthesis. 4v-MDRD: four-variable modification of diet in renal disease, CG: Cockcroft-Gault, CKD-EPI: chronic kidney disease epidemiology collaboration, eGFR: estimated Glomerular Filtration Rate, CKD: chronic kidney disease, G1: category one, G2: category two, G3: category three, G4: category four, and G5: category five.
Using the predictive equations, renal dysfunction was found to be highest in participants aged 70 years or more except for the 4v-MDRD and CKD-EPI equations where the scores were highest among the 50-59 years age group. Among the hypertensive medications, patients on Diuretics and AR Blockers presented with the highest scores using the predictive CKD equations. Generally, study participants on combination therapy of three medications presented with the greatest percentage of kidney dysfunction (see Table
Prevalence of renal dysfunction stratified by age and medication.
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<50 | 2 (7.40) | 4th | 1 (3.70) | 4th | 1 (3.70) | 4th |
50-59 | 11 (22.00) | 2nd | 10 (20.00) | 1st | 10 (20.00) | 1st |
60-69 | 19 (21.35) | 3rd | 5 (5.62) | 3rd | 6 (6.74) | 3rd |
≥70 | 18 (56.25) | 1st | 3 (9.38) | 2nd | 4 (11.76) | 2nd |
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ACE Inhibitor | 27 (24.32) | 2nd | 10 (9.01) | 2rd | 11 (9.91) | 3rd |
CC Blocker | 36 (20.34) | 4th | 14 (7.91) | 3rd | 18 (10.17) | 2nd |
Diuretics | 6 (23.08) | 3rd | 4 (15.38) | 1st | 4 (15.38) | 1st |
AR Blocker | 17 (25.00) | 1st | 6 (8.82) | 4th | 6 (8.82) | 4th |
1 (12.50) | 5th | 0 (0.00) | 5th | 0 (0.00) | 5th | |
One | 7 (29.17) | 3rd | 2 (8.33) | 3rd | 3 (12.50) | 2nd |
Two | 24 (25.00) | 4th | 9 (9.38) | 2nd | 8 (6.56) | 4th |
Three | 6 (31.58) | 2nd | 3 (15.79) | 1st | 8 (18.18) | 1st |
Four | 1 (33.33) | 1st | 0 (0.0) | 4rh | 1 (10.00) | 3rd |
Data is presented as frequency with percentage in parenthesis. 4v-MDRD: four-variable modification of diet in renal disease, CG: Cockcroft-Gault, CKD-EPI: chronic kidney disease epidemiology collaboration. ACE inhibitor: angiotensin converting enzyme inhibitor, and CC blocker: calcium channel blocker.
In the present study, the prevalence of renal impairment among the study population was estimated at 25.00%, 9.50%, and 10.50% using CG, 4v-MDRD, and CKD-EPI predictive equations, respectively. With the exception of CG equation (29.85% vs 22.56%; p=0.3002), the prevalence of renal impairment among participants presenting with both diabetes and hypertension was significantly higher compared to participants presenting with only hypertension (Table
Although information is dearth in the present study to explaining the difference in kidney disease burden between the current work and others in various jurisdictions, a host of factors have been suggested to contribute to this phenomenon including difference in population characteristics, geographical location, ethnicity, hereditary, type of definitive criteria used in estimating kidney dysfunction, laboratory method employed and the presence of other CKD risk profiles as well as disease severity [
Gender preponderance to impaired renal function has been shown to be skewed toward the female gender [
In the present study, using the predictive CKD equations, renal dysfunction was found to be highest in participants aged 70 years or more except for 4v-MDRD and CKD-EPI equations where the CKD scores were highest among the 50-59 years age group (Table
The advent of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII) 2003 guidelines has seen a surge in the treatment and control of hypertension with antihypertensive medications in people with kidney dysfunction [
The present study is limited in its cross-sectional design; hence causal relationship of renal impairment could not be established. Serum creatinine assay (picric acid method) adopted from the manufacturer was not traceable to the standardized isotope dilution mass spectrometry (IDMS). The study also relied on a single measurement of serum creatinine and estimation of GFR instead of two measurements three months apart in addition to urine protein estimation to determine urine albumin/creatinine ratio (ACR). This could lead to many missed cases of kidney damage.
The burden of renal dysfunction is high among Ghanaian hypertensive clients in the Asutifi-South District of the Brong-Ahafo Region. Females and participants presenting with comorbidity (both hypertension and diabetes) were most affected by renal dysfunction. Older age, thiazide diuretic and AR Blocker medications, increasing duration of antihypertensive therapy, and their combination were associated with greater kidney dysfunction. Regular screening and management are therefore recommended to avert progression to end-stage renal disease (ESRD).
The data used to support the findings of this study are available from the corresponding author upon request.
The authors declare no conflicts of interest.
This work was carried out with the collaboration of all authors. Authors have reviewed and certified the final manuscript for submission.