Abstract: SA-PO782

Osteocytic Perilacunar/Canalicular Turnover in Dialysis Patients with High and Low Serum PTH Levels

Session Information

Category: Dialysis

  • 601 Standard Hemodialysis for ESRD

Authors

  • Yajima, Aiji, Indiana University, Indianapolis, Indiana, United States
  • Tsuchiya, Ken, Tokyo Women's Medical University, Shinjuku-ku, Japan
  • Nitta, Kosaku, Tokyo Women's Medical University, Shinjuku-ku, Japan
Background

Osteocytic perilacunar/canalicular turnover in hemodialysis (HD) patients has not yet been reported, despite its particular relationship to bone and mineral metabolism in these patients. Under these circumstances, we were prompted to investigate osteocytic perilacunar/canalicular turnover in CKD patients.

Methods

Osteocyte lacunae in lamellar bone and woven bone were classified as eroded surface-, osteoid surface-, and quiescent surface-predominant osteocyte lacunae (ES-Lc, OS-Lc, QS-Lc, respectively) in HD patients with high or low parathyroid hormone (PTH) levels and control subjects without CKD.

Results

While the number of ES-Lc per unit bone volume (N.ES-Lc/B.Ar) was higher than N.OS-Lc/B.Ar in all groups [high-PTH (P<0.001) -, low-PTH (P=0.002) -, and control (P<0.001)], N.ES-Lc/B.Ar was higher in the high-PTH group than in the low-PTH (P<0.001) and control groups (P<0.001). The total volume of ES-Lc per unit bone volume (ES-Lc.Ar/B.Ar) was greater than OS-Lc.Ar/B.Ar in the high PTH (1.2 ± 0.4 vs. 0.5 ± 1.0 %, P<0.001) and the low-PTH groups (0.6 ± 0.3 vs. 0.1 ± 0.2 %, P<0.001). N.ES-Lc/B.Ar was higher in woven bone than in lamellar bone (P<0.001). MS/BS obtained from both groups were greater than that in the control group (1.15 ± 1.19 vs. 0.51 ± 0.38 %, P=0.039 and 0.92 ± 0.43 vs. 0.51 ± 0.38 %, P=0.016, respectively). Moreover, we could validate the shapes of the lacunar walls by backscattered electron microscopy.

Conclusion

Osteocytic perilacunar/canalicular turnover depends, at least in parts, on serum PTH level. Thus, attention should be paid to bone loss from the viewpoint of osteocytic parilacunar/canalicular turnover in HD patients.

Acknowledgment-We acknowledge Professor David B. Burr for analyses of the bone histomorphometric parameters and capturing of the images of osteocyte lacunae under the backscattered electron microscope. And we also acknowledge Dr. Keith W. Condon for his excellent technique to make bone samples for the observation by electron microscopy.