Chronic Kidney Disease Stages 3-5 in Iranian Children: Need for a School-based Screening Strategy: the CASPIAN-III Study

Background: there is scarce epidemiological data on early andasymptomatic stages of chronic kidney disease (ckd) in children,especially from developing countries. in this study, we investigatedthe frequency of ckd stages 3-5 among general students ofisfahan (a large province of iran), and compared the findings withthose derived from the main pediatric nephrology referral centerof province.methods: this study was performed among 712 isfahani schoolstudents (377 boys) aged 7-18 years, as part of the baseline surveyof a national surveillance system. blood samples were analyzedfor blood urea nitrogen, creatinine, and cystatin c. glomerularfiltration rate (gfr) was calculated based on two 2009 schwartzequations (the “updated” and the “new” equations). ckd wasdefined as gfr < 60 ml/min/1.73 m2. additionally, a retrospectiveanalysis of clinical records of children with stages 3-5 ckdreferred to main referral center of province from november 2001to december 2011 was made.results: the mean age of students was 12.2 ± 2.4 years. in students’screening, the frequency of ckd was 1.3% and 1.7% based onthe updated schwartz and the new schwartz equation, respectively.the referral center survey revealed an annual incidence of 14.5 permillion age-related population (pmarp), and a prevalence of 118.8pmarp in our province.conclusion: the prevalence of asymptomatic and undetected lowgfr in iranian children is higher than what is reflected from thereports of referral centers. simple screening programs like annualurinalysis among high-risk school students should be considered.