Secondary hyperparathyroidism (SHPT) may lead to weight loss and early mortality in patients on hemodialysis, investigators suggest.
Hirotaka Komaba, MD, PhD, of Tokai University School of Medicine in Isehara, Japan, and colleagues prospectively assessed 42,319 patients receiving in-center hemodialysis for more than a year from the international Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 2-6 (2002-2018).
Weight loss of more than 5% over 12 months occurred in greater proportions of patients with higher parathyroid hormone (PTH) levels: 21%, 18%, 18%, 17%, 15%, and 14% of patients with baseline PTH of 600 pg/mL or more, 450-600, 300-450, 150-300, 50-150, and less than 50 pg/mL, respectively, the investigators reported in the Journal of Cachexia, Sarcopenia and Muscle. Weight decreased over 12 months by 0.60%, 0.12%, 0.10% in patients with PTH of 600 or more, 450-600, and 300-450 pg/mL, respectively, compared with a reference PTH of 150-299 pg/mL, whereas weight increased by 0.15% and 0.35% in patients with PTH 50-150 and less than 50 pg/mL, respectively. The investigators could not account for any changes in fluid status, which is a study limitation.
Sensitivity analyses showed that the association between PTH and weight loss was stronger in patients with than without preserved appetite and persisted in patients who were not hospitalized. The association was less pronounced in Japan, where there was almost no association between PTH levels of 300 pg/mL or more and weight loss. Japanese guidelines recommend a much lower PTH target than North American guidelines, and Japanese patients may be treated sooner with pharmacotherapy or parathyroidectomy to lower PTH, the investigators suggested.
In mediation analysis, Dr Komaba and his colleagues found that weight loss of 2.5% or more accounted for 18% of the association between PTH and mortality over 12 months in patients with the highest baseline PTH category of 600 pg/mL or more.
“Our findings on the relationship between elevated PTH and weight loss support recent experimental evidence suggesting a direct role of PTH in adipose tissue browning and indicate that targeting this pathway may hold promise for ameliorating wasting,” Dr Komaba’s team wrote. Whether PTH-lowering therapy can halt weight loss in patients with SHPT receiving hemodialysis warrants further research, they noted.
Disclosure: This research was supported by Kyowa Kirin. Please see the original reference for a full list of disclosures.
Komaba H, Zhao J, Yamamoto S, et al. Secondary hyperparathyroidism, weight loss, and longer term mortality in haemodialysis patients: results from the DOPPS. J Cachexia Sarcopenia Muscle. Published online June 1, 2021. doi:10.1002/jcsm.12722