Glycemic control and survival of diabetic hemodialysis patients--importance of lower hemoglobin A1C levels.

AIMS: The significance of hemoglobin A1C (HbA1C) on the survival of diabetic hemodialysis patients still remains controversial. We investigated the impact of HbA1C on the survival. METHODS: A total of 122 diabetic patients on maintenance hemodialysis (age, 59.9+/-11.9 years [mean+/-SD]; hemodialysis duration: 53+/-38 months) were surveyed (survey period: 46+/-19 months). RESULTS: The cumulative survival of the poor glycemic control group (mean HbA1C of 3-month period > or =6.3%, n=62) was significantly lower than that of the good group (HbA1C<6.3%, n=60), as determined by Kaplan-Meier estimation (P=0.0084, log-rank test). Kaplan-Meier analysis also demonstrated that both cardiovascular and non-cardiovascular mortalities were higher in the poor group than in the good group (P=0.0545 and P=0.0453, respectively). In a multivariate Cox proportional hazard model, the mean HbA1C was a significant predictor of survival (OR 1.260 per 1.0%, 95% CI 1.020-0.579, P=0.0325). CONCLUSIONS: Poor glycemic control is an independent predictor of poor prognosis in diabetic hemodialysis patients. HbA1C is a clinically useful parameter for identifying the risk for mortality, both for cardiovascular and non-cardiovascular mortality, and that careful management of glycemic control by use of HbA1C is important.

Serum N-terminal midfragment vs. intact osteocalcin immunoradiometric assay as markers for bone turnover and bone loss in hemodialysis patients.

Although labile, assay of intact osteocalcin (iOC) is established as the standard assay for evaluating osteoblastic function. The present study examines the clinical usefulness of the newly developed immunoradiometric assay for osteocalcin (OC), which identifies the stable N-terminal midfragment of OC (N-MID OC assay), in hemodialysis (HD) patients. The performance of N-MID OC assay was compared to that of iOC assay in the sera obtained from 137 male HD patients, by comparing these assays with those of other bone metabolic markers and bone loss during a 1-year period before determination of serum markers. Serum N-MID OC values did not decrease significantly during 24 h incubation at room temperature, whereas serum iOC decreased significantly after 1 h incubation. Serum N-MID and iOC in the 137 male HD patients were 197.3 +/- 57.8 and 34.6 +/- 30.0 ng/ml, respectively, or 3.9 +/- 3.1 and 2.8 +/- 2.4 times above the respective reported normal upper limits. Serum N-MID OC correlated significantly in a positive manner with serum iOC (r = 0.934, P < 0.0001). Serum N-MID OC correlated no less significantly in a positive manner with serum levels of bone alkaline phosphatase, deoxypyridinoline, and intact parathyroid hormone compared to serum iOC. Of interest was the fact that serum N-MID OC, but not iOC, correlated significantly with both the amount and the rate of bone loss at the distal radius 1/3. In summary, the findings suggest that N-MID OC immunoreactivity is much more stable than iOC immunoreactivity and that N-MID OC assay may be less susceptible to the OC fragments reported to accumulate in uremic serum. It may, therefore, prove more reliable than iOC assay for evaluating bone turnover, and thus for reflecting bone loss, in HD patients.

Impaired secretion of parathyroid hormone is coherent to diabetic hemodialyzed patients.

Diabetic bone disease is characterized by low bone turnover resulting from impaired secretion of parathyroid hormone (PTH). However, it was suggested that the difference in duration of hemodialysis (HD) therapy and age of patients between HD patients with and without diabetes mellitus (DM) may be responsible for a significant reduction in serum intact PTH (iPTH) level in HD patients with DM. The present study showed that although such major factors affecting PTH secretion as age, sex, HD duration, and serum calcium, phosphate, and magnesium levels did not differ significantly between HD patients with and without DM, serum iPTH levels were still significantly lower in HD patients with than without DM. Among biochemical markers for bone metabolism, serum levels of intact osteocalcin (iOC) and deoxypyridinoline (DPD) were significantly lower in HD patients with than without DM, whereas serum bone-specific alkaline phosphatase, pyridinoline, and beta-crosslaps did not differ significantly between the two groups of patients. In summary, our findings indicate that PTH secretion may be significantly impaired in HD patients with DM compared with those without DM, and serum iOC and DPD are bone markers sensitive enough to detect low bone turnover in HD patients with DM.