Urinary growth hormone excretion in post-menarcheal adolescent girls with type 1 diabetes

The aim of the present study was to compare measurements of urinary growth hormone (GH), serum insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP3) between two groups of post-menarcheal girls, 13-18 y of age, one comprising 64 type 1 diabetic patients and the other 64 healthy girls matched for age and stage of puberty. GH was determined on two occasions in nocturnal urine samples by using a modification of an immunoradiometric method for serum. Significantly higher urinary GH concentrations but lower IGF-I and IGFBP3 levels were found in diabetic girls than in controls (p < 0.001). A significant correlation was found between urinary GH concentrations and the daily dose of insulin (U kg[-1]) (r = 0.426, p = 0.003). Urinary GH concentrations were also significantly related to HbA1c (r = 0.380, p = 0.003). In conclusion, disturbances of the GH-IGF-I axis may be evaluated by the use of non-invasive urinary GH measurements, which is a simple alternative to frequent sampling of serum GH. Increased GH secretion seems to be related to a great need for insulin and poor metabolic control. More knowledge about underlying causal factors in the disturbed GH-IGF-I axis is required.