[Relationship between fasting glycemia, serum peptide C, insulin, growth hormone and plasma glucagon in acromegaly]

The aim of this study was to investigate interrelations among fasting glycaemia, serum C-peptide, insulin, growth hormone and plasma glucagon concentration in people with acromegaly. 22 patients with active acromegaly, 11 women and 11 men (group A) and 19 healthy people (group K) participated in the study. The oral glucose tolerance test was carried out in all participants. Blood glucose, serum C-peptide, growth hormone and plasma glucagon concentration was measured. 13 patients with acromegaly had normal glucose tolerance (group AT) and 9 had impaired glucose tolerance (group AN). Statistical analysis was performed using Student's test and regression analysis. The comparison of patients from group A and K showed, that serum growth hormone, C-peptide, insulin, blood glucose concentration in fasting state was higher in acromegaly. There were no differences in fasting plasma glucagon concentration between both groups. Fasting glycaemia was similar in patients AT and controls, but there were also higher fasting serum C-peptide and insulin concentrations in the AT group. Fasting blood glucose, serum C-peptide and insulin concentration was higher in AN group than in controls. There were no significant differences in the above parameters between AT and AN group. Analysis of regression showed the negative correlation of fasting serum growth hormone and blood glucose concentration in the group A and AT. However there was no correlation between other parameters and fasting glycaemia, in particular between fasting glycaemia and insulin concentration. Fasting glycaemia positively correlated with fasting serum insulin concentration in healthy men. The comparison of glycaemia and fasting concentration of some hormones in patients with acromegaly regarding their glucose tolerance, did not answer the question, which hormonal abnormality is the most specific for disturbances of carbohydrate metabolism in acromegaly. Therefore groups of patients with markedly high of hormones in fasting state concentrations were distinguished. There was no difference in fasting glycaemia in this people compared to patients with normal or moderately elevated concentrations of hormones studied.

There is higher fasting glycaemia in patients with acromegaly compared to healthy men. Among them one can see subjects with normal glucose tolerance that is accompanied with high serum C-peptide and insulin concentration. Disturbances of glucose-insulin interregulation occur in these people.