# Advances in Chronic Kidney Disease in Africa
## 2 Challenges of Estimating GFR in SSA  
Estimating GFR (eGFR) based on the serum creatinine is the most practical way of determining the prevalence of CKD. The most common methods used are the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, which have been developed in high income countries and have not been validated against measured GFR (mGFR) in other regions, including SSA. Furthermore, both MDRD and CKD-EPI use a race-based correction factor for African Americans, which has become particularly controversial. In African Americans living with HIV, the racial adjustment adversely affected GFR estimates [5]. A new equation developed for both creatinine and cystatin C without racial adjustment appears to work reasonably well. However, eGFR was underestimated compared to mGFR in Blacks (median, 3.6 mL per minute per 1.73 m\({}^{2}\)) and overestimated compared to mGFR in non-Blacks (median, 3.9 mL per minute per 1.73 m\({}^{2}\)) [6]. Whether this correction factor is applicable to Africans living in Africa is also controversial as no major study has been performed comparing eGFR to mGFR in SSA. As a result, the true prevalence of CKD in Africa may be either overestimated or, more likely, underestimated. Accurately determining the prevalence of CKD in any country or region has major implications for health planning, given the high costs of treating CKD and the high associated morbidity and mortality. In a recent study by [PERSON] et al. conducted in Uganda, Malawi, and South Africa, 3025 subjects underwent determination of mGFR using the slope-intercept method for iohexol plasma clearance, and this was compared to eGFR using a variety of creatinine and  
Figure 1: The worldwide age-standardised global prevalence of CKD per 100,000 population in 2016 (adapted from reference [3]). In a systematic review conducted in Africa, the prevalence of CKD in people with type 1 and type 2 diabetes varied from 11% to 83.7% [19]. Incident event rates were 94.9% for proteinuria at 10 years of follow-up, 34.7% for ESRD at 5 years of follow-up and 18.4% for mortality from nephropathy at 20 years. Duration of diabetes, blood pressure (BP), advancing age, obesity, and glucose control were the common determinants of kidney disease. These figures strongly suggest a far greater incidence of DKD in Africa and higher incidence of morbidity and mortality. There is also a significant interaction with HIV, which is common, particularly in Southern Africa. In 2019, a retrospective study of 653 patients with diabetes from KwaZulu-Natal found a significant interaction with HIV on the prevalence of CKD [20]. Nephropathy, defined by proteinuria, was present in 25.66% vs. 15.43% of the HIV infected vs. non-infected patients, respectively. This finding was confirmed by a systematic review and meta-analysis conducted by [PERSON] et al. [21]. Most guidelines have advocated a multi-faceted approach to prevent DKD, entailing strict BP and diabetic control, the intensive treatment of dyslipidemia, the use of ACE inhibitors/angiotensin receptor blockers (ARBs), aspirin, and lifestyle intervention. This was based on the STENO-2 study that was associated with a 20% reduction in death and 47% reduction in nephropathy in the intensively treated group compared to standard treatment [22]. However, this approach has changed dramatically with the publication of clinical trials involving SGLT2 inhibitors. A full review of this is beyond the scope of this article, but, briefly, there was a striking reduction in CV death, heart failure, and \"hard\" kidney outcomes, including kidney failure, in a trial involving patients with diabetes with underlying atherosclerotic CV disease [23]. Several other studies reported similar results [24; 25]. Four dedicated CKD studies (two of which included patients without underlying diabetes) [26; 27; 28; 29] reported a consistent reduction in hard kidney end points, heart failure, and CV death, even in those without underling diabetes.