Background: The aim of the study is to elucidate whether parathyroid hormone (PTH) levels after parathyroidectomy affect the prognosis of patients with secondary hyperparathyroidism.
Subjects and methods: Two hundred and ninety-five patients, who underwent PTx without autotransplantation from July 1998 to December 2011, were divided into the low (n = 148) and high (n = 147) PTH groups, using the median value of each mean value of intact PTH after surgery (16.6 pg/mL). After observation for 5.00 years, we evaluated demographic factors, influences of postoperative mineral metabolism, magnitude of uremia, and vitamin D receptor activators on their prognosis, with the multivariate Cox proportional hazard model.
Results: While overall survival rates in the high and low PTH groups were 54.9 and 74.2 %, respectively (P = 0.1500), cardiovascular survival rates were 71.6 and 94.4 %, respectively (P = 0.0256). The hazard ratio for cardiovascular mortality in the high PTH group (≥16.6 pg/mL) was 3.132 (P = 0.0470), and those in groups with the median age more than 59 years and with cardiovascular disease were 2.654 (P = 0.0589) and 3.377 (P = 0.0317), respectively. The intact PTH level 6 days after surgery and the mean postoperative intact PTH value showed a strong correlation (Spearman ρ = 0.9007, P < 0.0001, y = 0.4725x + 30.395, R 2 = 0.51798).
Conclusion: The present study suggests that maintaining low PTH levels after parathyroidectomy reduces cardiovascular mortality and improves the prognosis. Total parathyroidectomy (more than 4 glands) without autotransplantation seems to be one of the treatment options for managing severe secondary hyperparathyroidism.
Keywords: Cardiovascular mortality; PTH; Parathyroidectomy; Secondary hyperparathyroidism.