[Diurnal rhythm of endogenous somatostatin in patients with carcinoid].

AIM OF THE STUDY

Was to investigate the differences of the circadian rhythm of the endogenous somatostatin in patients with carcinoid and in healthy probands.

METHODS

The group of 30 patients (16 men/14 women) was divided onto two groups. The group M of 20 (12/8) pts with metastatic disease and group B of 10 pts without known metastases at the time of investigation. The control group A included by 12 healthy probands (7/5). Plasma levels of somatostatin were determined by radioimmunoassay. Fisher periodogram and Halberg's cosinor were used for statistical evaluation.

RESULTS

We confirmed the 24-hour circadian rhythm of somatostatin in group A, B and M. Patients of the M group when compared with A and B groups had higher mesor and the later 24-hour acrophase (p < 0.05) and 12-hour acrophase (p < 0.05). Treatment with lanreotide led to the significant decrease of the somatostatin mesor (p < 0.05).