Insulin-like growth factor binding protein-1 as glucose regulator in adolescent boys with type 1 diabetes.
The aim of the present study was to investigate whether the diurnal variability of B-Glucose is dependent on GH, IGF-I and IGFBP-1 levels, apart from insulin, and if there is any difference between Tanner stages 3 and 5. Five boys in Tanner stage 3 and 6 boys in stage 5 with type 1 diabetes were included. Blood was continuously collected from a cubital vein for 24 h. S-Insulin, S-GH, S-IGF-I and S-IGFBP-1 were analysed. B-Glucose was analysed hourly at bedside. One week before and 1 wk after the 24-h study period the participants performed self-monitoring of blood glucose (SMBG) during normal physiologic conditions. In the 24-h profile of B-Glucose, insulin, IGFBP-1 and GH, we found a significant positive correlation between B-Glucose and log IGFBP-1 (r = 0.5, p = 0.005) and an inverse correlation to insulin (r = -0.5, p = 0.004) but no correlation to logGH (r = -0.04, p = 0.831). In multiple regression analysis, B-Glucose was still significantly correlated to log IGFBP-1, when adjusting for insulin and GH, in Tanner stage 5. We found a difference between Tanner stages 3 and 5 in the variability of B-Glucose over a longer period during normal daily activity (p = 0.02), but not over the 24-h study period.


CONCLUSIONS
We have demonstrated in type 1 diabetes adolescent boys a relationship between simultaneously measured blood-glucose and IGFBP-1 levels independent of the insulin and GH levels, suggesting that the free fraction of IGF-I influences the glucose metabolism.
Zachrisson
I
I
Astrid Lindgren Children's Hospital, Karolinska Institute, Stockholm, Sweden. ingza@child.ks.se
Dahlquist
G
G
Wallensteen
M
M
Brismar
K
K
D000293:Adolescent; D002648:Child; D002940:Circadian Rhythm; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000502:physiology*; D008297:Male
D018970:Insulin-Like Growth Factor Binding Protein 1; D005947:Glucose