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Insulin Increases Plasma Somatomedin C (IGF‐1) Concentrations in Adult Type 1 Diabetic Patientss
Author(s) -
Bristow A. F.,
Clarke R. F.,
Grant P. J.,
Stickland M. H.,
Wales J. K.
Publication year - 1989
Publication title -
diabetic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.474
H-Index - 145
eISSN - 1464-5491
pISSN - 0742-3071
DOI - 10.1111/j.1464-5491.1989.tb01155.x
Subject(s) - medicine , somatomedin , endocrinology , insulin , hyperinsulinemia , diabetes mellitus , glucose clamp technique , growth hormone , pancreatic hormone , hormone , insulin resistance
The role of insulin in the control of somatomedin release has been investigated in people with Type 1 diabetes. Six patients underwent insulin‐induced hypoglycaemia of 20 min duration and 8 patients were studied using the hyperinsulinaemic euglycaemic clamp technique at insulin infusion rates of 0.25, 1.25, 2.5, and 0.25 mU kg −1 min −1 for 1 h at each rate. In the first study plasma insulin concentrations rose from (median, range) 23 (10–36) to 114(60–200) mU I −1 at the onset of hypoglycaemia, and fell to 53 (23–100) mU I −1 after 20 min hypoglycaemia and 30 (15–73) mU I −1 on return to normoglycaemia. Plasma IGF‐1 rose from 140 (96–292) to 179 (127–352) μg I −1 ( p < 0.05) at the onset of hypoglycaemia and fell to 131 (125–173) μg I −1 after 20 min and to 154 (121–287) μg I −1 at the end of the study. During hyperinsulinaemia plasma insulin rose from 23 (19–40) mU I −1 at the lowest infusion rate to 61 (33–84) and 148 (68–200) mU I −1 at the two higher infusion rates. Over the same period, plasma IGF‐1 increased from 91 (13–203) to 123 (98–182) μg I −1 ( p < 0.05) and 109 (84–160) μg I −1 . There was no correlation between growth hormone levels and IGF‐1 in either study. These results suggest that insulin produces short‐term increases in IGF‐1 levels in man in the absence of a growth hormone response.