title: Different aspects of kidney function in well-controlled congenital hypothyroidism.
abstract: OBJECTIVE
  Congenital hypothyroidism (CH) increases the prevalence of kidney and urogenital malformations. There are limited studies considering different aspects of kidney function in well-controlled CH patients. We evaluated some features of kidney function in euthyroid children with CH who have been receiving thyroxine hormone since early life.
  
  
  METHODS
  This cross-sectional study was conducted in Isfahan, Iran, on 74 children aged 2-15 years old (36 CH patients and 38 healthy children). Inclusion criteria for CH patients were euthyroidism at the time of the survey and initiation of replacement therapy during the early neonatal period. Kidney ultrasound evaluation was performed in all participants. Serum biochemistry included urea, creatinine, sodium (Na), potassium (K), magnesium, calcium, and cystatin C levels. Urine electrolytes, fraction excretion (FE) of electrolytes and microalbumin, and glomerular filtration rate (GFR) were also determined.
  
  
  RESULTS
  The male/female ratio was 0.8/1 and 1.5/1 in the patient and control groups, respectively. Mean age and height did not differ significantly between the two groups. Ultrasound evaluation of the kidney revealed that the anteroposterior diameter of the right kidney was significantly higher in CH patients as compared to healthy subjects. No significant difference was observed between GFRs in patients with CH and healthy children. The mean values for FENa and FEK were significantly higher in the patient group.
  
  
  CONCLUSIONS
  Increased FENa and FEK may be a manifestation of impaired tubular maturation in CH. More longitudinal studies are needed to evaluate kidney function in CH patients.
authors.affiliation: IUMS, Pediatric Nephrology, Isfahan, Islamic Republic of Iran. gheisari@med.mui.ac.ir
authors.forename: Alaleh
authors.initials: A
authors.lastname: Gheissari
authors.forename: Mahin
authors.initials: M
authors.lastname: Hashemipour
authors.forename: Pooya
authors.initials: P
authors.lastname: Khosravi
authors.forename: Atoosa
authors.initials: A
authors.lastname: Adibi
mesh_terms: D000293:Adolescent; D000419:Albuminuria / Q000209:etiology; D000465:Algorithms; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003409:Congenital Hypothyroidism / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology* / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D020249:Hormone Replacement Therapy; D006801:Humans; D007492:Iran / Q000453:epidemiology; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009929:Organ Size; D051437:Renal Insufficiency / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D012720:Severity of Illness Index; D012737:Sex Factors; D013974:Thyroxine / Q000627:therapeutic use*; D014463:Ultrasonography
chemical_list: D013974:Thyroxine