Changes in serum prolactin, sex hormones and thyroid function with alternate nightly nocturnal home haemodialysis.

Objective: Uraemia is associated with hyperprolactinaemia, low total (TT) and free (FT) serum testosterone, high luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and, in women, anovulatory cycles and premature menopause. We hypothesize that extended hours haemodialysis may improve these derangements.

Methods: This is an observational cohort study of 30 men (age 54±13 years, body mass index (BMI) 28.1±5.8 kg/m2) and seven women (age 41±11 years, BMI 32.2±11.2 kg/m2) established on chronic home haemodialysis (3-5 h, 3.5-5 sessions weekly) who were converted to nocturnal home haemodialysis (6-9 h, 3.5-5 sessions weekly). Serum was collected at baseline and 6 months for measurement of TT, sex hormone binding globulin (SHBG), LH, FSH, prolactin, thyroid-stimulating hormone and thyroxine.

Results: In the male patients (n=25), serum prolactin significantly fell (281 (209.5-520) vs 243 (187-359) mU/L, P=0.001) and TT (12.6±5.8 vs 15.2±8.1 nmol/L, P=0.06) and FT (281±118 vs 359±221 pmol/L, P=0.01) increased. SHBG, LH and FSH were unchanged. At 6 months, two of the three women under 40 years of age had return of regular menses after being amenorrhoeic or having prolonged and irregular menses at baseline. There were insufficient women in this study to further analyse changes in sex hormone levels. Thyroid function tests remained stable.

Conclusions: Alternate nightly nocturnal haemodialysis significantly improves hyperprolactinaemia and hypotestosteronaemia in men. Menstrual cycling may be re-established in young women. The effect of these changes on fertility has not been established. Patients should be counselled about the possibility of increased fertility before conversion to extended hours haemodialysis regimens.