Renal function in Laron syndrome patients treated by insulin-like growth factor-I.
Eight children with Laron syndrome (5 males, 3 females) aged 3-14.5 years received daily subcutaneous injections of 150 micrograms/kg recombinant insulin-like growth factor-I (IGF-I) for 5 months. The children were examined weekly for the 1st month and then once monthly. At each visit, overnight fasting blood was drawn for serum IGF-I and blood chemistry measurements and a 24-h urine collection was performed for the determination of calcium, phosphorus, creatinine and nitrogen. The main effects related to kidney function were: an initial weight gain with a mild transitory reduction in the urinary volume, an increase in serum electrolyte concentrations and a decrease in urinary electrolyte excretion. The lower than normal mean (+/- SEM) basal creatinine clearance (76.7 +/- 15.8 ml/min per 1.73 m2) increased towards the normal range during treatment to 124.9 +/- 13 ml/min per 1.73 m2, with a mean increment of 73.4 +/- 28% (P < 0.02) from basal values after 2 months of treatment, without changes in the serum creatinine. Initially an increase in blood urea nitrogen was observed together with a reduction in urinary nitrogen excretion. During the IGF-I therapy the urinary calcium excretion increased from 0.7 +/- 0.2 nmol/day to 1.5 +/- 0.3 nmol/day and the tubular reabsorption of phosphate increased from 1.24 +/- 0.06 to more than 1.38 +/- 0.04 nmol/l (P < 0.002), resulting in a significant increase in serum phosphate levels from 1.51 +/- 0.06 to more than 1.63 +/- 0.04 nmol/l (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Klinger
B
B
Endocrinology and Diabetes Research Unit, Children's Medical Centre of Israel, Petah Tikva, Israel.
Laron
Z
Z
D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D001806:Blood Urea Nitrogen; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood / Q000652:urine; D004573:Electrolytes / Q000097:blood / Q000652:urine; D005260:Female; D006130:Growth Disorders / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D009584:Nitrogen / Q000652:urine; D010758:Phosphorus / Q000097:blood; D010783:Photometry; D017526:Receptor, IGF Type 1 / Q000172:deficiency*; D013577:Syndrome
D004573:Electrolytes; D010758:Phosphorus; D007334:Insulin-Like Growth Factor I; D003404:Creatinine; D017526:Receptor, IGF Type 1; D000469:Alkaline Phosphatase; D009584:Nitrogen