Secondary hyperparathyroidism (SHPT) is associated with progression of chronic kidney disease (CKD) and possibly cardiovascular events independently of hyperphosphatemia, a new study finds.
To assess the risk of CKD progression (defined as a 30% decrease in estimated glomerular filtration rate [eGFR] or dialysis initiation), investigators analyzed data from 1283 patients with stage 3 to 5 CKD not receiving dialysis who participated in the National Observatory of Atherosclerosis in Nephrology (NEFRONA) study. Compared with patients who did not have SHPT, those with SHPT had 2.13-fold increased adjusted odds of CKD progression after 2 years, José M. Valdivielso, PhD, and colleagues of the Vascular and Renal Translational Research Group, Biomedical Research Institute, IRBLLEIDA, in Lleida, Spain, and colleagues reported in Nephrology Dialysis Transplantation. SHPT was defined according to 2003 Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines or treatment with cinacalcet or active vitamin D compounds. Parathyroid hormone (PTH) levels over 70, 110, and 300 pg/mL defined SHPT in CKD stage 3, 4, and 5, respectively. To assess the independent effects of SHPT, patients with concurrent hyperphosphatemia or treated with phosphate binders were excluded from this analysis.
Among patients with hyperphosphatemia only, the odds of CKD progression after 2 years were significantly increased by 4.97-fold, the investigators also reported.
The risk for fatal and nonfatal cardiovascular events was increased by 37%, albeit nonsignificantly, in patients with vs without SHPT in an adjusted analysis of the larger cohort of 2445 patients with CKD, including those on dialysis. The risk for cardiovascular events was significantly increased by 44% in patients with vs without hyperphosphatemia, the investigators reported.
Hypercalcemia did not play a role in CKD progression or cardiovascular events, according to analyses. Hypercalcemia also did not modify the effects of SHPT. The investigators lacked data on another important variable, fibroblast growth factor 23 (FGF23) levels, which is a study limitation.
According to Dr Valdivielso’s team, “the presence of SHPT and hyperphosphatemia are independently associated with the progression of CKD. Hyperphosphatemia is also independently associated with cardiovascular incidence, and SHPT showed a trend to higher risk. Therefore, the reduction of both PTH and phosphate levels could be needed in order to improve the prognosis of CKD patients.”
Disclosure: This research was supported by VIFOR Pharma and ABBVIE. Please see the original reference for a full list of disclosures.
Bozic M, Diaz-Tocados JM, Bermudez-Lopez M, et al. Independent effects of secondary hyperparathyroidism and hyperphosphatemia on chronic kidney disease progression and cardiovascular events: an analysis from the NEFRONA cohort. Nephrol Dial Transplant. Published online May 21, 2021. doi:10.1093/ndt/gfab184