Association of impaired kidney function with mortality in rural Uganda: results of a general population cohort study

Abstract

ObjectiveTo determine the association between baseline kidney function and subsequent all-cause mortality.Design and settingA general population-based cohort study from rural Uganda.ParticipantsPeople aged 18 years and above with measured baseline estimated glomerular filtration rate (eGFR), recruited from survey rounds in 2011–2012 or 2014–2015 and followed up to March 2019.Outcome measureThe primary outcome was all-cause mortality, identified through reports from community health workers and verified by verbal autopsy. The association between baseline eGFR category and mortality was determined using multivariable Cox regression.ResultsOf 5812 participants in both rounds, we included 5678 (97.7%) participants with kidney function and mortality data; the median age was 36 years (IQR 24–50), 60.7% were female, 10.3% were hypertensive, 9.8% were HIV-positive and 1.5% were diabetic. During a median follow-up of 5.0 years (IQR 3.7–6.0) there were 140 deaths. In age-adjusted and sex-adjusted analyses, eGFR <45 mL/min/1.73 m2 at baseline was associated with a 5.97 (95% CI 2.55 to 13.98) increased risk of mortality compared with those with baseline eGFR >90 mL/min/1.73 m2. After inclusion of additional confounders (HIV, body mass index, diabetes, hypertension, alcohol and smoking status) into the model, eGFR <45 mL/min/1.73 m2 at baseline remained strongly associated with mortality (HR 6.12, 95% CI 2.27 to 16.45), although the sample size fell to 3102. Test for trend showed strong evidence (p<0.001) that the rate of mortality increased progressively as the category of baseline kidney function decreased. When very high eGFR was included as a separate category in age-adjusted and sex-adjusted analyses, baseline eGFR ≥120 mL/min/1.73 m2 was associated with increased risk of mortality (HR 2.68, 95% CI 1.47 to 4.87) compared with the reference category of 90–119 mL/min/1.73 m2.ConclusionIn a prospective cohort in rural Uganda we found that impaired baseline kidney function was associated with subsequently increased total mortality. Improved understanding of the determinants of kidney disease and its progression is needed in order to inform interventions for prevention and treatment.

Death after cure: Mortality among pulmonary tuberculosis survivors in rural Uganda

“…The mortality rate in our study (25 per 1000 person-years) is comparable to that reported in rural Ethiopia among TB survivors [ 3 ]. This rate is 5-9.5 times higher than the mortality rate reported in the general rural population in Uganda [ 6 , 7 ]. The high incidence of mortality is of concern since the majority of those who died were in their productive years (20-60 years of age).…”

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

“…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 24,72,81 . In a predominantly young (66% aged <45 years) rural Ugandan community, the adjusted population attributable fraction of CKD due to key risk factors was 39.2%, and CKD despite the much lower prevalence of traditional risk factors was associated with a 6‐fold risk of mortality 82,83 . Africans living in rural areas faces unique risk factors for CKDu, such as exposure to pesticides, use of traditional medicines, drinking unsafe water, unsafe storage of foodstuffs (exposure to fungi secondary products) and infections 42,44,80 .…”

“…24,72,81 In a predominantly young (66% aged <45 years) rural Ugandan community, the adjusted population attributable fraction of CKD due to key risk factors was 39.2%, and CKD despite the much lower prevalence of traditional risk factors was associated with a 6-fold risk of mortality. 82,83 Africans living in rural areas faces unique risk factors for CKDu, such as exposure to pesticides, use of traditional medicines, drinking unsafe water, unsafe storage of foodstuffs (exposure to fungi secondary products) and infections. 42,44,80 These may constitute significant CKD risk factors previously unidentified among this population, as history of exposure to pesticides and drinking unsafe water were, respectively, associated with 2.1 and 2.8-fold risks of CKDu.…”