Bone Metabolism In Hemodialysis Patients Research Articles

Relationships of Serum Levels of Insulinlike Growth Factors with Indices of Bone Metabolism and Nutritional Conditions in Hemodialysis Patients

Insulinlike growth factor (IGF) I and IGF-II are synthesized in osteoblasts and stimulate proliferation, differentiation, and matrix synthesis in these cells. There is some evidence that IGFs act on bone cells not only by paracrine but also by endocrine pathways, suggesting that circulating IGFs may be of importance for the regulation of bone metabolism. On the other hand, the serum IGF-I level is also thought to be a good indicator of the nutritional conditions in hemodialysis patients. The present study was performed to analyze the correlations of circulating levels of IGF-I, IGF-II, IGF-binding protein (IGFBP) 1 and IGFBP-3 with biochemical markers of bone metabolism and parameters of the urea kinetic model which reflect nutritional conditions in hemodialysis patients. We also examined the differences between these relationships in male and female patients on hemodialysis. Sixty-two hemodialysis patients, 36 men (male group) and 26 women (female group), were included in this study. We measured the serum levels of IGF-I, IGF-II, IGFBP-1, and IGFBP-3. The bone mineral content (BMC) of the radius was measured by dual-energy X-ray absorptiometry. We calculated Kt/V, protein catabolic rate, and percent creatinine generation rate (%CGR). We also examined the relationships between serum levels of IGFs and BMC and the parameters of the urea kinetic model. It was found that the serum levels of IGF-I in the hemodialysis patients were almost the same as those in the control group. However, the serum levels of IGF-II, IGFBP-1, and IGFBP-3 in the hemodialysis patients were significantly higher than those in the control group. In the male group, the serum IGF-I levels showed a significant correlation with both serum intact parathyroid hormone levels and BMC, but no significant correlations between these indices were found in the female group. The serum levels of both IGF-I and IGF-II showed significant correlations with %CGR in the male group, but not in the female group. Stepwise multiple regression analysis was performed to clarify the relationship between serum levels of IGFs and BMC or %CGR. It was found that age, hemodialysis duration, serum intact parathyroid hormone levels, and sex were independent factors associated with BMC. The %CGR was associated independently with serum levels of IGF-I, and IGF-II and with the presence of diabetes mellitus. In conclusion, it is thought that serum levels of IGF-I and IGF-II can be used as indices of nutritional conditions in hemodialysis patients. However, the serum IGF-I level cannot be used as a marker of bone metabolism in hemodialysis patients.

血液透析患者におけるメナテトレノン（Ｖｉｔ． Ｋ２＝ＭＫ‐４）の骨代謝に及ぼす影響 投与前後の骨代謝マーカーの変動

血液透析患者におけるメナテトレノン（Ｖｉｔ． Ｋ２＝ＭＫ‐４）の骨代謝に及ぼす影響 投与前後の骨代謝マーカーの変動

Serum pyridinoline as a specific marker of collagen breakdown and bone metabolism in hemodialysis patients

Type I collagen represents more than 90% of bone matrix. Quantitative analysis of collagen cross-link molecules such as pyridinoline (PYD) provides valuable information on bone resorption rate. We have studied 37 hemodialysis patients who underwent a systematic transiliac bone biopsy for histomorphometry study. Eighteen of them had tetracycline double labeling, allowing to determine dynamic, in addition to static bone parameters. Measurement of serum-free PYD was performed using a new competitive enzyme immunoassay. Serum PYD values were compared with those of three other serum markers of bone metabolism, namely intact PTH (iPTH), bone-specific alkaline phosphatase (bAP), and osteocalcin, for the correlations with bone histomorphometric parameters. Serum PYD levels (mean +/- SD) were significantly higher in dialysis patients than in normal individuals, 90.6 +/- 99.6 nM versus 1.9 +/- 0.4 nM, respectively. Patients with high turnover bone disease had significantly higher serum PYD levels than patients with normal or low bone turnover, 108.8 +/- 108.0 nM versus 34.1 +/- 12.8 nM, respectively. Serum PYD levels were positively correlated with bone resorption parameters including osteoclast surface (r = 0.59, p < 0.0001) and osteoclast number/mm2 (r = 0.61, p < 0.0001), and also with bone formation parameters, osteoblast surface (r = 0.43, p < 0.008), double-labeled surface (r = 0.81, p < 0.001), and BFR (r = 0.91, p < 0.0001). The BFR was better correlated with serum PYD levels than with either serum iPTH or osteocalcin concentrations. However, correlation with serum bAP was comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

A study of bone metabolism in hemodialysis patients

A study of bone metabolism in hemodialysis patients