Biochemical alteration in children with idiopathic nephrotic syndrome associated with an increased risk of sensorineural hearing loss; additional insights in cochlear renal relationship

ObjectivesChildren with Idiopathic Nephrotic Syndrome (INS) are at risk of hearing loss due to the adverse impact of medications and related immunological and genetic factors on both cochlea and kidney. So this work was planned to evaluate hearing status in children with INS and to clarify the possible associated risk factors by interpreting the clinical and laboratory profiles of those children.MethodsNinety children with INS aged 5-14 years [30 patients with steroid-sensitive nephrotic syndrome (SSNS), 30 patients with steroid dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS), and 30 patients with steroid-resistant nephrotic syndrome (SRNS)], and 90 age and sex matched normal controls were enrolled into this study. Laboratory measurements of serum calcium, creatinine, cholesterol, blood urea and other relevant investigations were done. Pure tone audiometry was done with the sensory-neural hearing loss (SNHL) diagnosed when the level bone conduction was >20 dB and the difference in air to the bone gap was <15 dB.Results40% children with INS had SNHL, mostly of mild degree HL and primarily occurred at the lower frequencies. A highly significant statistical difference between controls and various types of nephrotic syndrome regarding pure tone audiometry measurements at frequencies 250, 500, 1000 Hz, whereas insignificant difference interpreting pure tone audiometry measurements in 2000, 4000 and 8000 Hz.ConclusionsChildren with different phenotypes of nephrotic syndrome are at risk of sensorineural hearing impairment. The hazards associated with this impairment were higher blood pressure, hypercholesterolemia, hypoalbuminemia, and hypocalcemia.