Finding parathyroid nodules on ultrasound supports treatment with parathyroidectomy for dialysis patients with secondary hyperparathyroidism, a new study suggests.
“The presence of parathyroid nodules is associated with poorer bone metabolic profile in patients with severe hyperparathyroidism,” stated Claudia Ribeiro, MD, of Santa Casa de Belo Horizonte Hospital in Brazil, and colleagues.
The investigators retrospectively reviewed ultrasound imaging and laboratory results for 85 patients from the hospital with stage 5 chronic kidney disease (CKD) who had parathyroid hormone levels (PTH) exceeding 800 pg/mL. Of these, 66.4% had at least 1 nodule of rapidly growing parathyroid cells based on ultrasonography, as well as elevated levels of PTH, calcium, and phosphorus.
All were treated with calcitriol initially, then vitamin D analogues if no response, followed by withdrawal of treatment in cases of hypercalcemia, hyperphosphatemia, calcium by phosphate product above 55 mg/dL, or PTH below 200 pg/mL. No one received calcimimetics.
According to results published in the World Journal of Nephrology (2016;5: 437-447), the 16 patients with nodules who underwent parathyroidectomy (PTx) had worse pre-operative bone metabolic profiles, including higher levels of phosphorus and calcium × phosphorus product, in line with previous studies. Following surgery, these patients had lower mortality compared with non-surgery patients with nodules (32% vs 68%), as well as fewer cardiovascular and cerebrovascular events (27% vs 73%). Bone metabolic profiles improved for PTx patients, whereas they worsened among those not undergoing surgery.
Having a calcium × phosphorus product above 55 mg2/dL2 was associated with a 48% higher risk of death. The investigators observed higher mortality among those with a history of vascular events or vascular calcification, but found no direct link between the presence of nodules and early death.
The researchers observed no obvious differences in demographic and clinical characteristics between patients with and without nodules. Glomerular and vascular diseases were the underlying causes of CKD for both groups. The researchers acknowledged, however, that some relevant factors were not evaluated, such as fibroblast growth factor 23.
“The identification of nodules at ultrasonography strengthens the indication for parathyroidectomy in patients with secondary hyperparathyroidism due to renal failure, Dr Ribeiro and colleagues concluded.
1. 1. Ribeiro C, Goretti Moreira Guimarães Penido M, Moreira Guimarães MM, et al. Parathyroid ultrasonography and bone metabolic profile of patients on dialysis with hyperparathyroidism. World J Nephrol 2016 September 6; 5(5): 437-447. doi: 10.5527/wjn.v5.i5.437.