Background. The influence of long-term, low doses of prednison administration (< 0.3 mg/kg/day) on glucoregulation and glucose tolerance was studied in 20 female patients (15-20 yrs), including veri%cation of possibility to correct the impairment of glucose tolerance (IGT) by metformin (M). Methods and Results. During prednison treatment, we found typical signs of insulin resistance manifestation: HOMA,e 3.55 (5.13), blond insulin/glucose raflo 3.8 (5.84), QUICKI 0.61 (0.124). These were associated with higher Langerhans (L.) islets hormone secretion detected under basal conditions as well as after bolus of 5 g arginine chloride. However, detailed analysis of hormone secretion ratios revealed distinct signs of L. islets function impairment and subcompensation. Speci%cally, low rado C peptide/proinsulin and C peptide/glucagon were characteristicaly observed. Six months of M. administration (1000 mg/day) had a bene%cial effect on glucose metabolisms deviations as indicated by the following: insulin resistance decreased (HOMA,e 1.96 (1.60), insulin/glucose raflo 2.34 (1.52), QUICKI inereased at 0.699 (0.238)). At the same fime we found a decrease in the basal levels of insulin, proinsulin, glucagon, C peptide and amyline, and AUC proinsulin and glucagon as well. HOMAse~~euo„ decreased from an initial value of 389 (376) to 207 (119). Conclusions. Judging by the new hormonal secretion ratios, the L. islets' function following M. treatment substantially improved. From the clinical point of view, it is important to note that M. was toleraned very well. No patient interrupted the follow up because of M. intolerance. IGT in the whole group normalised, in spíte of the fact that no accent was put on the regime, diet including. The 90% of lactate values did not exceed 1.7 mmol/1. Based on the results, we may conclude that M. has a beneflcial effect on long-term, low doses of glucocorticoid-related (induced) glucose metabolism impairment, and therefore, M. administration could be recommended, particularly in the situations with higher levels of glycosylated hemoglobin.

        Key words: glucocorticoids, insulin resistance, glucoregulation, metformin, Langerhans islets, glucose tolerance.