DOI: https://doi.org/10.36347/sasjm.2026.v12i04.012

Pages: 296-303

Background: Elevated parathyroid hormone (PTH) is a common laboratory finding, but its interpretation depends on calcium status, renal function, phosphate, and vitamin D. In hospital-based populations, chronic kidney disease and vitamin D deficiency are major confounders, particularly when PTH elevation occurs without hypercalcemia. This study aimed to describe the biochemical profile and operational phenotypes of elevated PTH in a non-renal adult hospital laboratory cohort. Methods: We performed a retrospective, single-center, laboratory-based study over January–December 2025. Adults with elevated PTH and same-date measurements of total calcium, albumin, phosphate, creatinine, and 25-hydroxyvitamin D [25(OH)D] were eligible. Patients with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² were excluded to minimize inclusion of chronic kidney disease-related secondary hyperparathyroidism. Albumin-corrected calcium was calculated, and operational phenotypes were defined according to corrected calcium and vitamin D status using a 30 ng/mL 25(OH)D cutoff. Associations between PTH and biochemical variables were assessed using Spearman rank correlation. Results: The final analytical cohort included 168 non-renal adults (78.6% female) with a median age of 55.0 years (IQR 43.0–62.0). Median PTH was 107.0 pg/mL (IQR 85.8–133.0), median corrected calcium was 88.6 mg/L (IQR 85.2–92.5), and median 25(OH)D was 14.35 ng/mL (IQR 10.0–24.0). Vitamin D deficiency [25(OH)D <30 ng/mL] was present in 83.3% of patients, including 23.2% with severe deficiency (<10 ng/mL). Most patients were normocalcemic (73.2%), while 22.6% were hypocalcemic and 4.2% were hypercalcemic. The predominant operational phenotype was an elevated-PTH profile likely related to vitamin D deficiency (79.2%). An operational normocalcemic hyperparathyroid phenotype without vitamin D deficiency accounted for 15.5% of cases, while a hypercalcemic phenotype compatible with probable primary hyperparathyroi