Diagnostic Utility of Vitamin D-Parathyroid Hormone Axis and Mineral Biomarkers in Osteoporotic Iraqi Men

Abstract

Male osteoporosis is underdiagnosed. The vitamin D-parathyroid hormone (PTH) axis governs mineral homeostasis, but its diagnostic utility in Middle Eastern populations remains underexplored. 

To evaluate alterations in calcium, phosphorus, vitamin D, and parathyroid hormone, and assess their diagnostic performance for osteoporosis in Iraqi men.

A case-control study analyzed 120 men (60 osteoporotic >50 years; 60 age-matched controls >50 years). Osteoporosis was diagnosed based on clinical criteria including DEXA T-score and/or fragility fracture history. Calcium and phosphorus were measured colorimetrically. 25-hydroxyvitamin D and intact parathyroid hormone were quantified via chemiluminescence immunoassay.

Osteoporotic patients had lower calcium (2.02±0.15 vs. 2.17±0.11 mmol/L, p<0.0001) and vitamin D (17.51±8.75 vs. 28.38±13.4 ng/mL, p<0.0001) than controls. Conversely, phosphorus (1.26±0.2 vs. 1.18±0.16 mmol/L, p<0.05) and PTH (45.9±13.9 vs. 31.3±9.17 pg/mL, p<0.001) were elevated. ROC analysis showed good accuracy for parathyroid hormone (AUC=0.80), fair-to-good for calcium and vitamin D (AUC=0.77 each), and poor for phosphorus (AUC=0.54).

Osteoporosis in Iraqi men features mineral metabolism dysregulation, driven by vitamin D deficiency-induced secondary hyperparathyroidism. Assessing the vitamin D-parathyroid hormone axis alongside calcium provides reliable diagnostic utility, highlighting the need for targeted endocrine evaluation.