Real-world biochemical control in Chinese adult-onset hypoparathyroidism patients

Hypoparathyroidism(HypoPT) is rare, and real-world studies of biochemical control in affected patients are limited. This study aimed to analyze biochemical control in a large cohort of patients with adult-onset chronic HypoPT. Subjects were selected from outpatients followed at our center from June 2009 to March 2023. Proportion of measurements in/above/below the target range (MIR/MAR/MBR) and estimated time in/above/below the target range (TIR/TAR/TBR) were calculated. A total of 114 post-surgical (PS-HP) and 64 non-surgical (NS-HP) patients were enrolled, with a median follow-up of 82.5(45.0,108.0) months. The MIR/TIR were 70∼80% for serum calcium (Ca), around 40% for serum phosphorus(P), 80∼90% for 24-hour urine calcium(24hUCa), nearly 100% for calcium-phosphate products, 50∼64% for combined index 1(serum Ca and 24hUCa), and 20∼25% for combined index 2(all four indices). A total of 21 episodes of hypercalcemia occurred in 7 (3.93%) patients among the total 3455 measurements (0.61%). Compared to PS-HP patients, NS-HP patients showed poorer control of serum P, 24hUCa and combined indices. Serum Ca at diagnosis was positively associated with serum Ca TIR (β=21.15, P<0.05). Calcitriol dosage recorded at the last follow-up was negatively associated with TIR of serum Ca (β=-35.30, P<0.01) and 24hUCa (β = -66.19, P < 0.05). Hydrochlorothiazide use recorded at the last follow-up was associated with a 20.99% lower 24hUCa TIR (P < 0.001). Male patients showed higher serum P TIR than female (β1=28.14, P<0.001; β2=16.96, P<0.05). The control of serum Ca and 24hUCa was acceptable, whereas serum P and overall indices were suboptimal in our center. NS-HP patients showed poorer biochemical control than PS-HP patients and need more attention.