Albuminuria Is Associated with Multidimensional Cardiorenal injury in Adults with Steady-State Sickle Cell Disease: A Multicenter Study with Measured GFR

Background Albuminuria is an early marker of glomerular injury in sickle cell disease (SCD) and predicts progressive renal impairment. Data on albuminuria among adults with SCD in sub-Saharan Africa remain limited. This study aimed to determine the prevalence of albuminuria and identify associated factors in adults with steady-state SCD in Kinshasa, Democratic Republic of Congo. Methods We conducted a multicenter cross-sectional study including 279 adults (≥ 18 years) with steady-state SCD. Albuminuria was assessed using the urinary albumin-to-creatinine ratio (UACR) and categorized according to KDIGO criteria. Glomerular filtration rate (GFR) was measured by plasma iohexol clearance. Cardiac function was evaluated by Doppler echocardiography, and arterial stiffness was assessed using pulse wave velocity (PWV). Multivariate linear and logistic regression analyses were performed to identify independent determinants of albuminuria. Results The overall prevalence of albuminuria was 29.1%, including 21.5% grade A2 and 7.5% grade A3. Albuminuria was associated with elevated systolic blood pressure (SBP), lactate dehydrogenase (LDH), PWV, increased cardiac output, and reduced systemic vascular resistance (SVR). In multivariate analysis, urinary α-1 microglobulin ≥ 12 mg/L (aOR 3.01, 95% CI 1.80–4.02), recent vaso-occlusive crisis (aOR 2.71, 95% CI 1.22–4.21), LDH > 246 IU/L (aOR 3.57, 95% CI 2.40–6.13), and SVR < 700 dyn·s/cm⁵ (aOR 1.91, 95% CI 1.51–7.15) remained independently associated with albuminuria. Conclusions Nearly one-third of adults with steady-state SCD had albuminuria. Hemolysis, tubular injury, recent vaso-occlusive events, and vascular dysfunction were key determinants, highlighting the interplay between glomerular hyperfiltration and systemic vasculopathy. Longitudinal studies are warranted to assess persistence and progression of renal involvement.