Spontaneous declines in parathyroid hormone (PTH) in patients with acute comorbid conditions are associated with a higher risk of death than PTH decreases resulting from medical or surgical treatment of secondary hyperparathyroidism (SHPT), a new study suggests.
The findings suggest that fears of low PTH should not cause clinicians to underestimate the risks of SHPT and defer treatment. “Medical or surgical therapy should be implemented in order to prevent a negative impact of SHPT on bone and vascular health,” Guillaume Jean, MD, of NephroCare in France, and colleagues concluded in BMC Nephrology.
The investigators divided 197 conventional HD patients at their center by whether or not they had a drop in PTH levels, defined as a decrease of more than 50% in less than 3 months. They then stratified patients with low PTH by the underlying cause. Of the 197 patients, 34% had no PTH decline, 35% had a spontaneous decline without any change in therapy, 25% experienced a decline due to a change in medical treatment, and 6% had low PTH following subtotal parathyroidectomy. The main acute illnesses among patients with spontaneous PTH decline were peripheral vascular and cardiac complications, sepsis, fractures, and cancers with an underlying increase in serum C-reactive protein level and a decrease in serum albumin. In the medically treated group, the main therapeutic change was an increase in dialysate calcium concentration with or without cinacalcet therapy.
The 5-year survival rates were lower for patients with no decline or a spontaneous decline from illness compared with those receiving SHPT treatments. Results were not modified after adjustment for dialysis vintage, peripheral vascular disease, stroke, diabetes, cardiac disease, serum albumin, central venous catheter use, and warfarin treatment.
Median survival was 10 months for those with spontaneous PTH decline versus 22 months among patients receiving SHPT-related medications. Multivariate analyses revealed 58% lower risk of death among patients who had medical treatment compared with those who had no PTH decline and 64% lower risk of death compared with the group with spontaneous PTH decline. No deaths were observed in the surgery group, perhaps due to the small numbers.
1. 1. Guillaume J, Souberbielle JC, Zaoui E, Lorriaux C, Hurot JM, Mayor B, Deleaval P, Mehdi M, and Chazot C. Analysis of the kinetics of the parathyroid hormone, and of associated patient outcomes, in a cohort of haemodialysis patients. BMC Nephrology. 201617:153. doi: 10.1186/s12882-016-0365-9.