Progression of chronic kidney disease among black patients attending a tertiary hospital in Johannesburg, South Africa

Incidence, long-term predictors and progression of chronic kidney disease among African migrants and non-migrants: the transcontinental population-based prospective RODAM cohort study

BACKGROUND

Limited longitudinal data exist on chronic kidney disease (CKD) in African populations undergoing epidemiological transitions. We investigated incidence, long-term predictors and progression of CKD among Ghanaians residing in Ghana and Ghanaian migrants in the Netherlands (Amsterdam).

METHODS AND FINDINGS

We analysed data from 2183 participants in the transcontinental population-based prospective Research on Obesity and Diabetes among African Migrants cohort, followed for approximately 7 years. CKD incidence and its progression to end-stage kidney disease (ESKD) were defined using Kidney Disease: Improving Global Outcomes (KDIGO) criteria. CKD incidence was calculated using age- and sex standardisation for those without CKD at baseline. Long-term predictors of CKD incidence were identified using one-step robust Poisson regression. CKD progression to ESKD from baseline was also assessed using robust Poisson regressions. Overall age- and sex standardised CKD incidence was 11.0% (95% CI 9.3% to 12.3%) in the population, with Ghanaians residing in Amsterdam at (7.6%; 5.7% to 9.5%) and Ghanaians residing in Ghana at (12.9%; 10.9% to 14.9%). Within Ghana, rural Ghanaians had similar CKD incidence to urban Ghanaians (12.5%; 8.5% to 15.5% vs 12.3%; 8.2% to 15.8%). Residence in Amsterdam was associated with lower CKD incidence compared with Ghana after adjustments (incidence rate ratio=0.32; 0.13-0.77). CKD incidence predictors were advanced age, female sex, alcohol consumption, uric acid levels and hypertension. CKD progression to ESKD was 2.3% among Ghanaians residing in Ghana and 0.0% among Ghanaians residing in Amsterdam.

CONCLUSION

One-tenth of Ghanaians developed CKD over 7 years, with higher incidence in Ghana compared with Europe. Age, female sex, alcohol use, uric acid levels and hypertension were predictive factors. CKD progression to ESKD was minimal. High CKD incidence among Ghanaians, especially those residing in Ghana, calls for in-depth assessment of contributing factors and targeted interventions.

Epidemiology and referral patterns of patients living with chronic kidney disease in Johannesburg, South Africa: A single centre experience

Chronic kidney disease (CKD) is a significant contributor to the global burden of non-communicable disease. Early intervention may facilitate slowing down of progression of CKD; recognition of at-risk patient groups may improve detection through screening. We retrospectively reviewed the clinical records of 960 patients attending a specialist nephrology outpatient clinic during the period 1 January 2011-31 December 2021. A significant proportion (47.8%) of patients were referred with established CKD stage G4 or G5. Non-national immigration status, previous diagnosis with diabetes, and advancing age were associated with late referral; antecedent diagnosis with HIV reduced the odds of late referral. Black African patients comprised most of the sample cohort and were younger at referral and more frequently female than other ethnicities; non-nationals were younger at referral than South Africans. Hypertension-associated kidney disease was the leading ascribed aetiological factor for CKD (40.7% of cases), followed by diabetic kidney disease (DKD) (19%), glomerular disease (12.5%), and HIV-associated kidney disease (11.8%). Hypertension-related (25.9%) and diabetic (10.7%) kidney diseases were not uncommon in people living with HIV. Advancing age and male sex increased the likelihood of diagnosis with hypertensive nephropathy, DKD and obstructive uropathy; males were additionally at increased risk of HIV-associated kidney disease and nephrotoxin exposure, as were patients of Black African ethnicity. In summary, this data shows that hypertension, diabetes, and HIV remain important aetiological factors in CKD in the South African context. Despite the well-described risk of CKD in these disorders, referral to nephrology services occurs late. Interventions and policy actions targeting at-risk populations are required to improve referral practices.