Supported Research

Lay Summary
Nephrotic syndrome is the most common childhood kidney disease in the world. The rates of nephrotic syndrome have doubled over the past ten years in Ontario, where 5 children per 100,000 children are affected. South Asian children are affected by nephrotic syndrome more frequently, with a 6-times higher occurrence than European children. Steroids are the basis of treatment not only at initial presentation, but also at each subsequent relapse. If the child is steroid resistant, dependent, or frequently relapsing, steroid-sparing immunosuppressive medications are often used. Overall most children do well, and in about 85% of children the disease has been cured by adulthood. Unfortunately, there is a significant exposure to steroids and at least half of the children have a prolonged and repeated exposure to other immunosuppressive drugs. Despite prolonged exposure to medications, the risks of developing other chronic diseases related to repeated exposure to steroids and other steroid-sparing medications are unknown. Specifically, we do not know if these children develop chronic kidney disease, cardiovascular disease, diabetes, fractures, infertility or cancer. Our goal is to determine the risk of these long-term complications in individuals with childhood nephrotic syndrome as they age into young adults. We will compare the overall risk of complications to that in healthy children from Ontario.

We propose to study around 1500 children with idiopathic nephrotic syndrome from 4 pediatric centers in Ontario (Toronto, Hamilton, Ottawa and London) with equal access to healthcare. We will collect health data from the medical charts of these children and link it with provincial health administrative data to determine the rates of complications. Results of the study will provide the rationale for clinical practice guidelines on screening for comorbidities and potentially alternative treatment strategies to lessen the risk. If there is no difference in risk, we can reassure families about prolonged steroid use and choice of steroid sparing agent. We will also develop methods to determine specific kidney outcomes in children using administrative data. Our overall goal is to provide more robust estimates of the burden for these important outcomes that result from having childhood nephrotic syndrome or arise from treatment with steroids and other nonsteroidal immunosuppressive drugs. This study addresses important patient-centered outcomes and will provide key information in counselling patients and families on the risks of nephrotic syndrome and related medications.