Low parathyroid hormone and pentosidine in hemodialysis patients

Background: Accumulation of advanced glycation end products (AGEs) has been linked to the severity of osteoarticular and cardiovascular damage in patients with end-stage renal disease. Methods: We studied the relationship between plasma pentosidine and parathyroid hormone (PTH) levels and bone turnover in a group of hemodialysis patients (n = 85) with minimal aluminum exposure. Results: Plasma pentosidine levels were greater than the upper limit of normal range (cutoff value, 2.46 pmol/mg protein) in all dialysis patients. When patients were divided into three tertiles according to plasma pentosidine levels, serum PTH levels were approximately six times lower in patients in the third pentosidine tertile than in those in the first tertile (P = 0.008), and a similar association (P = 0.009) was found between pentosidine and bone alkaline phosphatase levels. Multivariate analysis confirmed that these relationships were independent of established risk factors for low bone turnover. Forty patients (47%) had serum PTH levels less than 125 pg/mL (13.2 pmol/L). Of note, in a multiple logistic regression model, the relative risk for low PTH level was 4.02 (95% confidence interval, 1.30 to 12.40; P = 0.02) times greater in patients in the third pentosidine tertile than in the first tertile. Conclusion: Pentosidine, a reliable indicator of AGEs, is related inversely to circulating PTH and bone alkaline phosphatase levels. These associations are in agreement with recent experimental data indicating that AGE accumulation may be a factor involved in low bone turnover in dialysis patients.