PTH and osteoporosis: A large-scale cohort study (n=135,034) based on the TriNetX database revealed that approximately 33.3% of hypercalcaemic patients were at risk of missed diagnosis of PHPT, with the undiagnosed group with PTH ≥50 pg/mL (14.9%) and the undetected PTH group (18.4%) exhibiting a significantly differentiated comorbidity profile: the former had a 2.64-fold increase in the risk of osteoporosis over 3 years compared with matched controls, and the urinary tract had a 2.64-fold increase in the risk of osteoporosis.