Serum parathyroid hormone trajectory during the first year of hemodialysis: a roadmap to severe hyperparathyroidism

Abstract

Background: Data on parathyroid hormone (PTH) levels at hemodialysis (HD) initiation and during the first year of therapy are still scarce. We hypothesized that high baseline PTH levels contribute to more severe hyperparathyroidism during this period.

Methods: Incident HD patients (n = 1,973) were divided into 3 groups according to PTH values (<150, 150-600, and > 600 pg/mL).

Results: PTH levels at baseline and at 1 year were 273 (133-508) and 255 (128-471) pg/mL, respectively (p = 0.291). PTH < 150, 150-600 and >600 pg/mL were found in 28.1, 53.5 and 18.4%, respectively, at baseline and 30.7, 52.5 and 16.8% after 1 year (p = 0.015). Younger age, absence of diabetes, high baseline alkaline phosphatase and PTH were independent risk factors for PTH > 600 pg/mL after 1 year of HD.

Conclusion: High PTH at the beginning and after 1 year of HD indicate poor conservative management before and during dialysis, and put patients at risk of requiring parathyroidectomy later.

Figure 1. PTH levels at baseline and after 1 year of hemodialysis. A – PTH values in the study group remained stable after one year of therapy, with no significant changes in the median levels compared to baseline. B – The distribution of PTH levels at 12 months, categorized by groups of initial levels of PTH, revealed that while half of the patients with baseline PTH > 600 pg/mL experienced a decrease in their serum levels, an equivalent number of patients from other groups increased PTH levels above 600 pg/mL. Consequently, the proportion of patients with uncontrolled hyperparathyroidism remained equal to baseline.

Figura 1. Níveis de PTH no início e após 1 ano de hemodiálise. A – Os valores de PTH no grupo de estudo permaneceram estáveis após um ano de terapia, sem alterações significativas nos níveis médios em comparação com o valor basal. B – A distribuição dos níveis de PTH aos 12 meses, categorizada por grupos de níveis iniciais de PTH, revelou que, enquanto metade dos pacientes com PTH basal > 600 pg/mL apresentou uma redução em seus níveis séricos, um número equivalente de pacientes de outros grupos aumentou os níveis de PTH acima de 600 pg/mL. Consequentemente, a proporção de pacientes com hiperparatireoidismo não controlado permaneceu igual ao valor basal.