Dialysis patients with refractory secondary hyperparathyroidism (SHPT) experience a survival advantage with parathyroidectomy, a new Taiwanese study confirms.
Parathyroidectomy (PTx) was associated with a significant 20% to 25% lower risk for mortality from any cause in the long term. To minimize concerns that surgery patients might be healthier, the researchers adjusted for co-existing diabetes and cardiovascular diseases (e.g., myocardial infarction, congestive heart failure), as well as demographic factors.
“Corroborating the effectiveness of PTx in the treatment of SHPT is of special importance in the era of calcimimetics,” lead researcher Junne-Ming Sung, MD, professor of medicine at National Cheng Kung University in Taiwan, and colleagues wrote in Scientific Reports. “Both PTx and calcimimetics aim to improve survival by suppressing iPTH levels, but their efficacies have been questioned due to the potential bias of previous cohort studies and the inconclusive results of the Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) trial.”
To minimize selection bias, the investigators enrolled only patients with severe SHPT confirmed by radionuclide parathyroid scanning. Of 2,786 hemodialysis and peritoneal dialysis patients in the Taiwanese National Health Insurance system during 1999-2010, 1,707 had parathyroidectomy and 1,079 acted as matched controls not undergoing the procedure.
The results corroborate findings from a study published by Bryan Kestenbaum, MD, and colleagues in Kidney International and (2004;66:2010-2016) that found a 10% to 15% lower risk of early death. They also complement a more recent Japanese study by Hirtotaka Komaba, MD, and colleagues published in the same journal (2015;88:350-359) that found a survival benefit. Both may have been subject to biases, prompting the current study.
How SHPT increases mortality is still unclear, according to the researchers, but some evidence points to a predisposition to cardiovascular disorders.
The investigators noted that they were unable to gauge the short-term (30-day) risk of death following PTx. They also lacked some potentially relevant data including iPTH, serum calcium, phosphorus, creatinine, serum albumin, urea clearance, and body mass index.
- Ho LC, Hung SY, Wang HH, et al. Parathyroidectomy Associates With Reduced Mortality in Taiwanese Dialysis Patients With Hyperparathyroidism. Scientific Reports. doi:10.1038/srep19150.