Serum endorphin levels in uremic patients under maintenance hemodialysis.

We checked serum beta-endorphin levels in 17 chronic uremic patients under regular hemodialysis and compared them with the levels in 17 age-matched control subjects. Higher levels of serum beta-endorphin were found in uremic patients (22.54 +/- 6.20 pg/0.1 ml vs 9.42 +/- 5.19 pg/0.1 ml, p less than 0.001). There were no sex differences in both uremic patients (M: F = 21.04 +/- 7.53 pg/0.1 ml vs 23.59 +/- 5.25 pg/0.1 ml, p greater than 0.05) and normal control subjects (9.16 +/- 5.15 pg/0.1 ml vs 9.76 +/- 5.55 pg/0.1 ml, p greater than 0.05). No significant difference in the serum levels was noted between the patients with a hemodialysis history longer than two years (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05) and those with less than a two year's history (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05). Moreover, serum beta-endorphin levels were not altered after dialysis (22.54 +/- 6.20 pg/0.1 ml to 20.66 +/- 4.57 pg/0.1 ml, p greater than 0.05) by either acetate or bicarbonate dialysate (acetate vs bicarbonate = 20.83 +/- 5.03 pg/0.1 ml vs 20.13 +/- 3.14 pg/0.1 ml, p greater than 0.05). The role of beta-endorphin in the pathogenesis of uremic syndrome still requires further study.