Estimated Glomerular Filtration Rate Predicts Incident Stroke Among Ghanaians with Diabetes and Hypertension

Background: Sub-Saharan Africa is currently experiencing a high burden of both chronic kidney disease (CKD) and stroke as a result of a rapid rise in shared common vascular risk factors such as hypertension and diabetes mellitus. However, no previous study has prospectively explored independent associations between CKD and incident stroke occurrence among indigenous Africans. This study sought to fill this knowledge gap.

Methods: A prospective cohort study involving Ghanaians adults with hypertension or type II diabetes mellitus from 5 public hospitals. Patients were followed every 2 months in clinic for 18 months and assessed clinically for first ever stroke by physicians. Serum creatinine derived estimated glomerular filtration rates (eGFR) were determined at baseline for 2631 (81.7%) out of 3296 participants. We assessed associations between eGFR and incident stroke using a multivariate Cox Proportional Hazards regression model.

Results: Stroke incidence rates (95% CI) increased with decreasing eGFR categories of 89, 60-88, 30-59 and <29 ml/min corresponding to incidence rates of 7.58 (3.58-13.51), 14.45 (9.07-21.92), 29.43 (15.95-50.04) and 66.23 (16.85-180.20)/1000 person-years respectively. Adjusted hazard ratios (95%CI) for stroke occurrence according to eGFR were 1.42 (0.63-3.21) for eGFR of 60-89 ml/min, 1.88 (1.17-3.02) for 30-59 ml/min and 1.52 (0.93-2.43) for <30 ml/min compared with eGFR of >89 ml/min. Adjusted HR for stroke occurrence among patients with hypertension with eGFR<60 ml/min was 3.69 (1.49-9.13), p = .0047 and among those with diabetes was 1.50 (0.56-3.98), p = .42.

Conclusion: CKD is dose-dependently associated with occurrence of incident strokes among Ghanaians with hypertension and diabetes mellitus. Further studies are warranted to explore interventions that could attenuate the risk of stroke attributable to renal disease among patients with hypertension in SSA.