Prevalence and risk factors for chronic kidney disease of unknown cause in Malawi: a cross-sectional analysis in a rural and urban population

Abstract

Background An epidemic of chronic kidney disease of unknown cause (CKDu) is occurring in rural communities in tropical regions of low-and middle-income countries in South America and India. Little information is available from Southern African countries which have similar climatic and occupational characteristics to CKDu-endemic countries. We investigated whether CKDu is prevalent in Malawi and identified its potential risk factors in this setting. Methods We conducted a cross-sectional study from January–August 2018 collecting bio samples and anthropometric data in two Malawian populations. The sample comprised adults > 18 years (n = 821) without diabetes, hypertension, and proteinuria. Estimates of glomerular filtration rate (eGFR) were calculated using the CKD-EPI equation. Linear and logistic regression models were applied with potential risk factors, to estimate risk of reduced eGFR. Results The mean eGFR was 117.1 ± 16.0 ml/min per 1.73m2 and the mean participant age was 33.5 ± 12.7 years. The prevalence of eGFR< 60 was 0.2% (95% confidence interval (95% CI) 0.1, 0.9); the prevalence of eGFR< 90 was 5% (95% CI =3.2, 6.3). We observed a higher prevalence in the rural population (5% (3.6, 7.8)), versus urban (3% (1.4, 6.7)). Age and BMI were associated with reduced eGFR< 90 [Odds ratio (OR) (95%CI) =3.59 (2.58, 5.21) per ten-year increment]; [OR (95%CI) =2.01 (1.27, 3.43) per 5 kg/m2 increment] respectively. No increased risk of eGFR < 90 was observed for rural participants [OR (95%CI) =1.75 (0.50, 6.30)]. Conclusions Reduced kidney function consistent with the definition of CKDu is not common in the areas of Malawi sampled, compared to that observed in other tropical or sub-tropical countries in Central America and South Asia. Reduced eGFR< 90 was related to age, BMI, and was more common in rural areas. These findings are important as they contradict some current hypothesis that CKDu is endemic across tropical and sub-tropical countries. This study has enabled standardized comparisons of impaired kidney function between and within tropical/subtropical regions of the world and will help form the basis for further etiological research, surveillance strategies, and the implementation and evaluation of interventions.

Association of indoor use of pesticides with CKD of unknown origin

“…The prevalence of CKD without hypertension and diabetes mellitus was approximately 36% in our study, while it was much lower in studies in Malawi (0.2%) and India (1.6%). Even though participants with proteinuria were excluded from the mentioned studies, our finding was more than expected(34,35).…”

Chronic kidney disease of unknown aetiology in Africa: A review of the literature

“…A CKDu study conducted among 821 individuals in Malawi estimated the point prevalence at 0.5%. 40 Eight studies reported on CKD burden attributable to CKDu were identified, including 21 871 individuals (Table 1). A community-based study among 320 participants in Cameroon reported that 42.3% of CKD patients were diagnosed as CKDu, and the patients were all with CKD Stage 3.…”

“…50 It is also estimated that, in rural Africa, CKDu might account for a larger proportion of the total CKD burden. 28,40,[42][43][44] In rural East Africa, for example, CKDu comprise 66% of the total CKD burden. 42 Additional studies from a rural environment in Nigeria and Tanzania have reported a higher CKD prevalence of 12.4%-27.6% not associated with diabetes, hypertension, obesity or HIV, a proxy for CKDu.…”

Bailing Capsule combined with α-ketoacid tablets for stage 3 chronic kidney disease

“…[ 1 , 2 ] It is mainly caused by diabetes, hypertension, and glomerulonephritis. [ 3 , 4 ] Initially, the symptoms of CKD are insidious and then presented with fatigue, swelling legs, dizziness, and loss of appetite gradually. After stage 3, the above symptoms become more obvious, with increased risks of hypertension, heart failure, bone disease, anemia, gastrointestinal symptoms, and a progress to end-stage kidney failure without proper intervention and treatment.…”

“…Chronic kidney disease (CKD) is a progressive and irreversible loss of kidney function, with an increased prevalence in recent years [1,2] . It is mainly caused by diabetes, hypertension, and glomerulonephritis [3,4] . Initially, the symptoms of CKD are insidious and then presented with fatigue, swelling legs, dizziness, and loss of appetite gradually.…”