PTH variability is associated with increased risk of mortality in Japanese hemodialysis patients

Elevated parathyroid hormone (PTH) levels are associated with cardiovascular events, bone disease, and mortality in patients undergoing maintenance hemodialysis. Although PTH levels vary widely in patients undergoing hemodialysis, whether this affects mortality is unclear.

A total of 315 maintenance hemodialysis patients who underwent PTH measurements at least twice a year were enrolled. The association between all-cause mortality, cardiovascular events, and fractures was evaluated in patients with PTH concentrations of 60-240 pg/mL (time-in-target range (TTR) 100%) and those with TTR values of 75% ≤ TTR < 100%, 50% ≤ TTR < 75%, and TTR < 50%.

There were 122 patients with TTR 100%, 81 patients with 75% ≤ TTR < 100%, 52 patients with 50% ≤ TTR < 75%, and 74 patients with TTR < 50%. Over the 4-year observation period, patients with TTR of 100% had significantly lower all-cause mortality than those with TTR < 50%. (HR 2.26, 95% CI 1.33-3.86) Subgroup analysis by presence or absence of pharmacological intervention showed no statistically significant difference in all-cause mortality in the treatment group (HR 2.08, 95% CI 1.16-3.72), but showed significant differences in the no-treatment group (HR 1.58, 95% CI 0.92-2.70).

A prolonged period of deviation from the optimal PTH range was associated with increased all-cause mortality, particularly among patients not receiving SHPT medication. However, this effect was not observed in patients who received pharmacological interventions. These results suggest that early intervention is desirable when PTH levels vary from the optimal range in patients with secondary hyperparathyroidism.