Changes in bone mineral content during long-term CAPD. Indication of a sex-dependent bone mineral loss.

Change in bone mineral content (BMC) was evaluated in a longitudinal trial comprising 12 women and 11 men with chronic renal disease treated with CAPD and 1-alpha-OH-D3 for 2 years. The patients served as their own controls. No patients were treated with steroids. Median age was 54 and 60 years for women and men respectively. No significant difference in 1-alpha-OH-D3 dosage or serum 1,25(OH)2D3 was found between the genders in the study period. Bone mineral content at the distal radius deteriorated significantly in the females with a median decrease of 12% over 2 years, i.e. approximately 6% per year (P < 0.001 and 95% confidence limits 8-20%). No significant change was noted in the males. There was no correlation between age and BMC change. Serum total alkaline phosphatase decreased nonsignificantly in both sexes. Total serum calcium increased significantly (P < 0.05) and serum phosphate decreased significantly (P < 0.05) in the women. Serum albumin and body weight decreased significantly in the males (P < 0.01 and P < 0.05) while no change was seen in the females. The demonstrated decrease in BMC in the female patients of approximately 6% per year exceeds the commonly observed loss of 1-2% per year in healthy women when measured with the same technique. Tentatively, the severe mineral loss in the women could indicate a sex-hormone-related disturbance in bone metabolism of uraemic females.