The frequency of laboratory testing for diagnosis and management of chronic kidney disease-mineral bone disorder (CKD-MBD) needs to improve, according to investigators.

Using a nationally representative US database including more than 50 million electronic health records from 2010 to 2019, researchers identified 215,553, 43,576, and 11,407 patients with stage 3, 4, and 5 CKD, respectively.

Among patients with stage 3, 4, and 5 CKD, only 26%, 46%, and 41% had initial parathyroid hormone (PTH) testing, 54%, 74%, and 73% had phosphorus testing, and 34%, 38%, and 25% had 25-hydroxyvitamin D (25D) testing, respectively, according to records, James B. Wetmore, MD, MS, of Hennepin Healthcare Research Institute in Minneapolis, Minnesota, and colleagues reported in Kidney International Reports. Further, among patients who received a prescription to treat secondary hyperparathyroidism (SHPT), only 50%, 53%, and 60% of patients with stage 3, 4, and 5 CKD had their PTH level retested after 1 year. Only 46%, 49%, and 55%, respectively, had 25D reassessed 1 year after treatment with ergocalciferol or cholecalciferol. Undertesting was common even among patients with high PTH or low 25D. Testing increased as phosphorus levels increased, but it was still suboptimal, according to the investigators.

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Prior to treatment, mean levels of PTH in patients with stage 3, 4, and 5 CKD were 154, 221, and 352 pg/mL, respectively. Mean levels of phosphorus were 4.6 mg/dL in stage 4 and 5.8 mg/dL in stage 5. Mean pre-treatment levels of 25D ranged from 20.9 in stage 3 to 24.3 ng/mL in stage 5.

After treatment with vitamin D sterols, only half of patients with stage 3, 4, and 5 had undergone PTH retesting at 12, 8, and 4.5 months, respectively, in line with Kidney Disease Improving Global Outcomes (KDIGO) recommendations, Dr Wetmore’s team reported.

“We found times to analyte retesting following treatment initiation to be longer than might be expected, and, perhaps most unexpectedly, that pre-treatment levels of PTH and 25D were not associated with the rate of retesting for secondary hyperparathyroidism or 25 D insufficiency, respectively,” the investigators stated. Cost and recent hospitalization might contribute to undertesting.

Nephrologists are potentially missing opportunities for CKD-MBD treatment, according to Dr Wetmore’s team.

Disclosure: This clinical trial was supported by OPKO Health. Please see the original reference for a full list of authors’ disclosures.


Wetmore JB, Ji Y, Ashfaq A, Gilbertson DT, Roetker NS. Testing patterns for CKD-MBD abnormalities in a sample US population. Published online January 5, 2021. Kidney Int Rep. doi:10.1016/j.ekir.2020.12.036