Changes in endogenous insulin secretion during childhood as expressed by plasma and urinary C-peptide.
Basal fasting values of plasma C-peptide (CP), plasma insulin and 24 h urine CP were determined in 224 normal non-obese subjects of both sexes ranging in age from 1 to 20 years. Analysis of the results by age, pubertal rating, sex and bone age (BA) during childhood showed that mean +/- SD plasma CP levels in both sexes rose from 0.07 +/- 0.08 pmol/ml at the age of 1-2 years to 0.21 +/- 0.11 pmol/ml at 8-10 years. Mean +/- SD plasma insulin levels in both sexes rose from 3.2 +/- 4.3 microU/ml at the age of 1-2 years to 5.9 +/- 4.5 microU/ml at 8-10 years. Mean +/- SD urine CP levels rose from 6.5 +/- 2.8 pmol/mg creatinine per 24 h at the age of 2-8 years to 7.7 +/- 3.5 pmol/mg creatinine per 24 h at 8-11 years in both sexes. During puberty, plasma and urine CP and plasma insulin levels rose further to peak at pubertal stage P3, the values in females being higher (CP = 0.32 +/- 0.06 pmol/ml) than those in males (CP = 0.22 +/- 0.06 pmol/ml) (P less than 0.005). Plasma insulin levels in females were 13.2 +/- 6.9 microU/ml and 6.4 +/- 3.1 microU/ml in males (P less than 0.05). Urine CP levels were 14.5 +/- 5.7 pmol/mg creatinine per 24 h and 10.8 +/- 5.4 pmol/mg creatinine per 24 h in females and males respectively (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Laron
Z
Z
Department of Pediatrics, Beilinson Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel.
Aurbach-Klipper
Y
Y
Flasterstein
B
B
Litwin
A
A
Dickerman
Z
Z
Heding
L G
LG
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002096:C-Peptide / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007328:Insulin / Q000097:blood*; D008297:Male; D011627:Puberty / Q000378:metabolism; D012737:Sex Factors
D002096:C-Peptide; D007328:Insulin