Factors Predictive of Glomerular Hyperfiltration in Sickle-Cell Anemia Males

Abstract

Background: Renal manifestations, including glomerular hyperfiltration during sickle cell disease (SCD), are very frequent and constitute the starting point for renal failure. Few data are available on this subject in Togo. The aim of this study was to describe the predictive factors of glomerular hyperfiltration in SCD in our Togolese context. Methods: This was a retrospective descriptive and analytical study carried out at the Centre National de Recherche et de Soins aux Drépanocytaires du Togo located in the commune of Lomé. Hyperfiltration was defined for all major sickle cell patients by a glomerular filtration rate (GFR) > 130 ml/min/1.73m 2 and renal failure by a GFR < 60 ml/min/1.73m 2 calculated according to the Modification of Diet in Renal Disease (MDRD) equation. We investigated factors associated with glomerular hyperfiltration using univariate and multivariate logistic regression. The dependent variable was GFR status > 130 coded 1 and 0 if not. Results: 82.0% of major sickle cell patients had glomerular hyperfiltration, and 1.7% were in renal failure. The mean age of our patients was 14.1 years, with a female predominance of 53.2%, giving a sex ratio (M/F) of 0.88. Homozygous sickle cell patients represented 55.3% of the population and heterozygous SC 38.5%. In a comparative analysis, there was a statistically significant difference between the proportion of patients with and without glomerular hyperfiltration according to age (p < 0.001), gender (p < 0.001), economic activity (p < 0.001), marital status (p < 0.001), educational level (p = 0.007), hemoglobin phenotype (p < 0.001), proportion of HbS (p < 0.001); to certain circumstances of discovery as painful crises (p = 0.002), infection (p < 0.001), hand-foot syndrome (p = 0.015) and asthenia (p = 0.032); of certain complications as occurrence of at least one complication (p = 0.025), anemia (p = 0.003), priapism (p = 0.048), renal failure (p = 0.001), osteonecrosis (p = 0.041) and retinopathy (p = 0.001). Risk factors for hyperfiltration were male gender (p = 0.016), age under 10 years (p = 0.001), age between 10 and 19 years (p < 0.001), hemoglobin S > 70% (p = 0.009) and low azotemia (p = 0.004). Conclusion: Glomerular hyperfiltration is very frequent in sickle cell disease syndromes in Togo, with a non-negligible presence of renal failure. Risk factors are dominated by a young age, as in the literature.