Plasma Somatoiedin-C in children and adolescents with IDDM

Abstract

Previous studies in diabetic patients have reported elevated normal and reduced somatomedin levels.We used RIA method to determine Somatomedin C (SMC) in 57 diabetic children and adolescents(29 f. and 28 m.;age range 2.75-20.16 yrs; duration of disease 0.08-15.85 yrs)and in 274 control subjects of the same age. SMC behaviour was not seen to be different from that of controls concerning those differences related to sex(SMC levels higher in f. than in m.,p<0.005)and to pubertal stage(SMC levels higher in pub.than in prepub.children ,p<0.0001).Plasma SMC levels in pubertal diabetic patients were not different from those of pubertal control children,while in prepubertal diabetic patients SMC was significantly lower than in the respective control children(p<0.0001).In the group of diabetic children,as a whole,there was no correlation between SMC and duration of disease,insulin dosage,HbA1,growth velocity standard deviation score.If we give separate consideration to pubertal and prepubertal subjects and exclude the influence of chronological age from this correlation,we find a significant negative correlation between SMC and HbA1.In diabetic subjects with no fluoroangiographic retinal changes the mean SMC value was not seen to differ from that encountered in subjects having retinal changes(microaneurysms,leakage,IRMA).In conclusion:1)SMC levels in diabetic patients are lower than in normal subjects; only as long as sex hormones do not eliminate this difference at puberty;2)poor control of disease has a negative influence on SMC only in pubertal subjects.