Growth Failure Associated With Parathyroid Hormone Levels in Pediatric Dialysis Patients: A Nationwide Cohort Study

Rationale & Objective: Growth failure is prevalent in pediatric dialysis patients. Physical growth is limited to a specific period, and missed interventions may cause lifelong growth retardation. We aimed to investigate the association of secondary hyperparathyroidism with short stature and height growth failure. Study Design: Cohort study. Setting & Participants: Patients aged 1-20 years who initiated dialysis and were registered in the nationwide dialysis registry of Japan between 2009 and 2020. Exposure: Intact parathyroid hormone (PTH) levels. Outcomes: Height standard deviation score (SDS), short stature (less than or equal to -2.0 SDS of height), height velocity SDS, and height growth failure (less than or equal to -1.5 SDS of height velocity). Analytical Approach: We examined the association between intact PTH levels and the outcomes in both cross-sectional and longitudinal analyses. Results: Intact PTH, height, and weight were measured in 622 patients. The median dialysis vintage was 10 months, the mean age was 13 years, 59% were boys, 50% were receiving peritoneal dialysis, and the median value of intact PTH was 183 pg/mL. At enrollment, the median height SDS was -1.9 (IQR, -3.3 to -0.6), and 302 patients (49%) had a short stature. The median SDS of height velocity during the first year was -2.4 (IQR, -5.6 to -1.5), and 205 patients (75%) had height growth failure (a decrease in height velocity). Elevated intact PTH levels per doubling were associated with a significant decrease in height velocity (β = -0.26; 95% CI, -0.49 to -0.02) and height growth failure (OR, 1.16; 95% CI, 1.00-1.34). Restricted cubic spline analysis showed a decrease in height velocity with increasing intact PTH levels. Limitations: Lacked data on recombinant human growth hormone use and limited follow-up periods to evaluate the impact of PTH on long-term growth. Conclusions: Our findings suggest the involvement of secondary hyperparathyroidism in height growth failure in pediatric dialysis patients.