In the present study the peritoneal dialysis patients
In the present study, the peritoneal dialysis patients underwent parathyroidectomy after a shorter duration of dialysis and at a lower PTH level. Although this nadph oxidase inhibitor finding may suggest treatment and referral bias, higher serum aluminum levels in these patients suggest that more peritoneal dialysis patients fail to be adequately treated with calcium-based phosphate binders. Data from the National Health Insurance Research Database showed that peritoneal dialysis patients had a higher incidence rate of parathyroidectomy (hazard ratio, 1.657) compared with hemodialysis patients. The PTH level is not the only factor in surgical referral. For patients who changed from peritoneal dialysis to hemodialysis, a progressive rise in PTH levels was observed. Higher PTH levels may be associated with a higher risk of high-turnover bone disease. This may partially explain why in Taiwan, hemodialysis patients had a greater risk of hip fracture compared with peritoneal dialysis patients. In our study, peritoneal dialysis patients tended to have higher preoperative BMD than hemodialysis patients, although the difference was not statistically significant. The perioperative course was similar for the two groups. Parathyroidectomy was associated with higher short-term, and lower long-term, mortality rates in ESRD patients. Short-term relative mortality risks did not differ appreciably by dialysis modality. In both groups, intact PTH and alkaline phosphatase levels decreased significantly after surgery. Nevertheless, peritoneal dialysis patients had higher postoperative calcium–phosphorus product levels and more severe residual symptoms compared with hemodialysis patients. The observation may result from higher serum aluminum levels. We clearly demonstrated that a high serum aluminum level was associated with reduced symptom improvement in patients undergoing parathyroidectomy. In this study, a marked difference was observed in mood swings (p = 0.053). A plausible explanation is that peritoneal dialysis patients had lower levels of 25-hydroxyvitamin D compared with hemodialysis patients. Research has suggested a role of vitamin D in mood disorders. A limitation of our study is that serum levels of 25-hydroxyvitamin D were not determined in our patients. The role of vitamin D deficiency requires further investigation. Pruritus was the most prominent symptom prior to parathyroidectomy. Consistent with our previous finding, the mean score of itching significantly dropped from 51 ± 30 to 31 ± 29 (p < 0.001) in hemodialysis patients. Nonetheless, the itching score of peritoneal dialysis patients did not change significantly (from 52 ± 26 to 48 ± 32, p = 0.702). This phenomenon may be attributed to higher calcium–phosphorus product levels in the peritoneal dialysis group than in the dialysis group, because histological studies have shown more calcium depositions in skin basal and spinous cells among patients with uremic pruritus. A high calcium–phosphorus product level increases the risk of soft tissue and vascular calcification. ESRD patients have higher odds of having pruritus if the calcium–phosphorus product level is high, and pruritus is associated with poor outcomes and higher mortality risk. Another possibility is that peritoneal dialysis patients had higher serum aluminum levels. As shown in our previous study, a high serum aluminum level was associated with reduced symptom alleviation. Data from the Taiwan National Health Insurance Research Database suggest that ESRD patients with secondary hyperparathyroidism have a greater risk of developing thyroid cancer. For a substantial minority of these patients, benign and malignant thyroid disease warranted surgical treatment at the time of parathyroidectomy. In this study, 95 (25%) patients had concurrent thyroid operations, including 13 patients for papillary thyroid cancer. The presence of thyroid neoplasms in our patients seems higher than that in the general population. The underlying mechanisms were unclear, but a negative association between PTH levels and some thyroid-disrupting agents (perchlorate, nitrate, and thiocyanate) has been reported. At our institute, surgeon-performed neck ultrasound is routinely conducted prior to the surgery. A comprehensive thyroid evaluation of patients referred for parathyroidectomy is recommended.