Insulin regulates the 35 kDa IGF binding protein in patients with diabetes mellitus.
The serum levels of the low molecular form of insulin-like growth factor binding protein (IGFBP) was determined in 56 outpatients with diabetes mellitus by a radioimmunoassay developed for amniotic 35 kDa IGFBP. The mean level of 35 kDa IGFBP was found to be threefold higher in insulin dependent diabetes mellitus (IDDM), 112 +/- 13 ng/ml, than in age matched controls, 37 +/- 2 ng/ml, while the mean level in non-insulin dependent diabetes mellitus (NIDDM), 16 +/- 2 ng/ml, was decreased. In hospitalized IDDM patients there was a significant correlation (r = 0.91, p less than 0.01) between fasting blood-glucose and 35 kDa IGFBP levels, not found in NIDDM patients. During insulin infusion the 35 kDa IGFBP levels declined with a half-life of 60-120 min. The decline in IGFBP continued even after the establishment of steady state B-glucose at 4.7 mmol/l. In conclusion, the elevated 35 kDa IGFBP levels in IDDM can be attributed to insulin deficiency and may reflect a reduced bioavailability of the IGFs at the target cells.
Brismar
K
K
Department of Endocrinology, Karolinska Hospital, Stockholm, Sweden.
Gutniak
M
M
Povoa
G
G
Werner
S
S
Hall
K
K
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002352:Carrier Proteins / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000378:metabolism* / Q000494:pharmacology; D018969:Insulin-Like Growth Factor Binding Proteins; D008875:Middle Aged
D001786:Blood Glucose; D002352:Carrier Proteins; D007328:Insulin; D018969:Insulin-Like Growth Factor Binding Proteins