The Study Of Relationship Between Serum Osteoprotegerin Level And Renal Osteodystrophy In Maintenance Hemodialysis Patients

The Study of Relationship between Serum Osteoprotegerin Level andRenal Osteodystrophy in Maintenance Hemodialysis Patients Background: Osteoprotegerin (OPG) was an important biological active substance which belonged to excretive glycoprotein found in tumor necrosis factor receptor superfamily in recent years. Its physiological function was to combine osteoclast differentiation factor, restrain the proliferation and activation of osteoclast and protect bone from losing bone mass. OPG acted an important role in bone metabolism. Renal osteodystrophy was almost existed in overall end-stage chronic renal failure (ESCRF) patients. The accurate interactivity mechanism between OPG and ESCRF was yet clarified. No domestic clinical report about relationship between OPG and renal osteodystrophy was found.Objective: To investigate the change of serum concentration of OPG in patients of ESCRF and the effects on its serum concentration given by hemodialysis. We also explore the significance that serum concentration of OPG evaluates the true bone status in maintenance hemodialysis patients. Methods: Twenty-nine maintenance hemodialysis patients and twenty-three healthy people were involved in this study. The level of serum OPG was measured by ELISA, intact parathyroid hormone was measured by radioimmunity assay, alkaline phosphates, calcium, phosphate, BUN, creatinine was also measured. The bone mineral density of lumbar spine, neck of femur, Ward's triangle of femur and trochanter of femur was measured by dual energy X-ray absorptionmetry. The whole data was analyzed by independent sample t-test, nonparametric test, correlation analysis, regression analysis and discriminate analysis.Results: The serum concentration of OPG in single pre-dialysis and post-dialysis in study group were higher than control group (P<0.0001and P=0.009 respectively). There was no significant change of serum concentration of OPG between single pre-dialysis and post-dialysis (P=0.88). A positive correlation between serum concentration of OPG before single hemodialysis was found (r=0.399 P=0.03).A positive correlation between serum concentration of OPG and age in health control was found (r=0.414 P<0.05).No correlation between serum concentration of OPG and bone mineral density of lumbar spine, neck of femur, Ward's triangle of femur and trochanter of femur was found. While the bone mineral density of neck of femar, Ward's triangle of femar and trochanter of femur in study group was lower than control group. (P<0.001). No difference of lumbar spine bone mineral density was found between study group and control group. A discriminate analysis was preformed between syntheses of OPG concentration, age, sex, body mass index, menopause parameter and accumulative dialysis time and bone status given by the dual energy X-ray absorptionmetry. The tally rate of bone status in trochanter given by the discriminant function was 80%.Conclusion: OPG serum concentration in ESCRF patients was higher than healthy people. OPG could not be cleared by hemodialysis. OPG might be one of the serum indicators which evaluate the abnormal bone metabolism status of renal osteodystrophy in ESCRF patients. The serum OPG level combine other five indicators mentioned above had a higher tally rate in evaluation of bone status in trochanter of femur. There was a clinical application value in diagnosis of bone status in ESCRF patients. OPG serum concentration was evaluated in accordance with the accumulation time of hemodialysis. In healthy people serum OPGconcentration was evaluated in accordance with age. This study combining to other literature clewed that the degree of elevated OPG may not enough to contradict the bone mass losing in ESCRF patients or resistance of OPG may exist in these patients.