Acute-phase reactants as predictors of chronic kidney disease incidence in Africans: the population-based prospective RODAM cohort study

Abstract Background Chronic kidney disease (CKD) and chronic inflammation are highly prevalent in African populations, yet their relationship remains understudied. We examined the association between acute-phase reactants (C-reactive protein and ferritin) as markers of acute and chronic inflammation and the incidence of CKD 6 years later in a prospective Ghanaian population-based cohort. Methods Data from the prospective Research on Obesity and Diabetes among African Migrants (RODAM-Pros) cohort were analysed and included participants living in rural and urban Ghana and Ghanaian migrants in the Netherlands. Acute-phase reactants were assessed between 2012 and 2015, while CKD incidence was assessed between 2019 and 2021 by using the race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation. Robust Poisson regression models adjusted for potential confounders were used to assess associations. We explored interactions with age, sex, education, and geographical location, and stratified C-reactive protein (CRP) analyses by using established clinical cutoffs. The role of ferritin as an iron-storage marker was also evaluated. Results Among 1435 participants, the baseline CRP was not associated with CKD incidence at follow-up [adjusted incidence rate ratio (aIRR) 1.02; 95% confidence interval (CI): 0.84–1.15]. Higher ferritin levels were associated with increased CKD risk (aIRR 3.53; 95% CI: 2.42–5.01) and albuminuria (aIRR 4.22; 95% CI: 2.87–6.10), but not with reduced estimated glomerular filtration rate (aIRR 0.99; 95% CI: 0.92–1.05). No effect modification was observed by age, sex, education, or geographical location. We found no evidence that iron overload or deficiency contributed to the ferritin–CKD relationship. Conclusion Elevated ferritin levels, but not CRP levels, were associated with future CKD risk in Ghanaians. Multi-population prospective studies with repeated ferritin measurements are needed to better understand the links between ferritin, iron status, and CKD in African populations.