[Bone mineral density in dialysis patients: the optimal region of interest depending on parathormone levels].

Frequency of osteoporosis in patients on dialysis with respect to the optimal Region of Interest (ROI) has not been established. Frequency of this complication varies in different studies, especially because of no agreement according to the optimal ROI. We studied 71 patients: 32 on CAPD and 39 on HD (31F, 40m. age mean 56 +/- 29) on dialysis for 3 to 81 months. BMD was measured using dual energy X-ray densitometry (DXA) in L1-L4 segment of the vertebral column, femoral neck and forearm. The results of the BMD were presented as T-score in the standard deviation of the mean peak bone mass according to WHO criteria. Males and females were evaluated separately. Depending on the ROI, osteoporosis was diagnosed in 20 to 68% of women and in 2 to 40% of men. In females the most sensitive region of interest appeared to be forearm, in males it was proximal part of the femur. In these ROI's the lowest values of bone mineral density in both genders were found in patients with the level of iPTH higher than 200 pg/ml. We did not find any significant difference in BMD between patients on CAPD and HD. Values of bone mineral density were not related to the duration of dialysis therapy. On the results of our study it has been concluded, that optimal region of interest for BMD evaluation in dialysed patients depends on gender of the patient and functional status of parathyroid glands but is not related to either the method or duration of dialysis therapy.