Diurnal rhythm and the effect of hemodialysis therapy on blood prolactin levels in patients with chronic renal insufficiency

: In 97 patients with different stages of chronic renal failure prolactin serum level was determined, and its diurnal rhythm and dependence on haemodialysis treatment were studied. Diurnal rhythm was investigated in 6 men and 6 women with advanced chronic renal failure on diet and other symptomatic treatment. A normal diurnal rhythm of prolactin was recorded only in 3 patients, two of them being with elevated basal prolactin levels; an abnormal prolactin rhythm was documented in 8 patients. In 4 patients no evident diurnal changes in prolactin level were observed, though 3 of them had a normal basal prolactin level. In one patient slight fluctuations of the prolactin level were recorded, while in 4 other patients an abnormal type of diurnal rhythm was observed. Prolactin determinations in patients on maintenance haemodialysis showed increased values in 45 men (719 + 122 mIU/l) as well as 34 women (1251 + 171 mIU/l). The analysis of the influence of haemodialysis on cuprophane and polyacrylonitrile membrane was made in 6 patients and no difference was shown between predialysis and postdialysis serum prolactin values, as well as in values obtained for non-dialysis and dialysis days. The results obtained in this study showed an absent or abnormal diurnal rhythm of prolactin in 75% of patients with chronic renal failure. In patients on maintenance haemodialysis increased prolactin levels were found. Haemodialysis procedure on cuprophane and polyacrylonitrile membrane failed to affect the serum level of prolactin.