Bone Mineral Density and Markers of Bone Turnover in Patients with End-Stage Renal Failure on Starting Hemodialysis

Song, Jong Hoon; Cha, Young Soo; Kook, Jin Whan; Cho, Yong Wook; Ahn, Jae Hyung

Abstract

Renal osteodystrophy is well recognized complication of end stage renal disease(ESRD) and is associated with a marked morbidity. To evaluate bone loss in renal osteodystrophy, we measured bone mineral density(BMD) in distal radius by quantitative computed tomography in 43 ESRD patients on starting hemodialysis(HD) and in 84 healthy controls matched for age and sex. We also measured intact parathyroid hormone(iPTH), serum total alkaline phosphatase(T-ALP), osteocalcin(OC) and urine deoxypyridinoline(U-DPD) as bone turn-over markers. 1) The mean age of ESRD patients and control groups were 49.8 and 49.7 years. M:F ratio were 1:1.1 and 1:1.3 on each groups. There was no significant differences on each groups. 2) Serum T-ALP and OC were 263.9+/-264.5U/L, 43.5+/-27.6ng/mL in ESRD patients and 167.4+/-46.6U/ L, 8.8+/-3.9ng/mL in control groups. These were significantly higher in ESRD patients(P<0.001, P< 0.001), while U-DPD were not significant difference on each groups(5.3+/-4.1 vs 5.4+/-1.9nM/mM. Cr.). 3) Serum iPTH and aluminum were 296.8+/-263.4pg/mL, 10.1+/-11.6ng/mL in ESRD patients. 4) Total density, trabecular density and cortical density were 340.4+/-83.6, 172.9+/-48.4, 477.2+/-123.5mg/ cm3 in ESRD patients and 393.2+/-49.1, 210.6+/-32.9, 541.3+/-76.2mg/cm3 in control groups. BMD was statistically significantly reduced in ESRD patients (P<0.001, P<0.001, P<0.001, respectively). Z score of total density and trabecular density were -0.62+/-1.12, -0.91+/-0.95 in ESRD patients and 0.19+/-0.68, 0.06+/-0.59 in control groups. It was significantly reduced in ESRD patients(P<0.001, P<0.001, P<0.001, respectively). 5) In ESRD patients, serum T-ALP, iPTH, OC, U-DPD were not correlated with BMD and Z score. But in control groups, serum OC was correlated inversly with BMD, and U-DPD was only correlated inversely with trabecular density. 6) In ESRD patients(n=22) who were having iPTH above 300pg/mL, serum OC and U-DPD were significantly higher than in ESRD patients(n=21) who were having iPTH below 300pg/mL(52.6+/-28.8ng/ mL, 6.8+/-5.1nM/mM.Cr. vs. 33.9+/-23.3ng/mL, 3.7+/-1.9 nM/mM.Cr. P<0.05, P<0.05 repectively). But serum aluminum, and T-ALP were not significant difference on each groups. BMD and Z score were also not difference on each groups. 7) In ESRD patients who were having iPTH above 300pg/mL, iPTH and serum OC were inversely correlated with BMD but U-DPD were only inversely correlated with trabecular density. In ESRD patients who were having iPTH below 300pg/mL, bone turn-over markers were not correlated with BMD. In ESRD patients on starting HD, BMD were significantly reduced, but serum T-ALP, OC, iPTH and U-DPD were not correlated with BMD. In ESRD patients who were having iPTH above 300 pg/mL, BMD were significantly inversely correlated with serum OC, iPTH.