Purpose: To evaluate adherence to European Society of Endocrinology guidelines and risk of renal complications in patients with chronic post-operative hypoparathyroidism (PO-HypoPT) treated with calcium and activated vitamin D metabolites.
Methods: We evaluated 90 adult patients (68 females and 22 males) with chronic (3 years) PO-HypoPT. Total albumin-corrected (Alb-Ca) and ionized serum calcium, phosphate, creatinine, PTH, and 24-h urinary calcium were measured; renal ultrasound was also performed. Healthy hospital employers (n = 142) were used as control.
Results: Complete data were available in 82 patients. Twenty-eight (34.1%) met four targets (Alb-Ca, phosphate, calcium phosphate product and 24-h urinary calcium), 36 (43.9%) three, 17 (20.7%) two, and 1 (1.2%) one. Thirteen (14.4%) had Alb-Ca value below and 18 (20.0%) above the target range and 54.9% 24-h urinary calcium above the upper normal limit. Seven (7.7%) has increased serum phosphate and none an increased calcium phosphate product. Eleven (12.2%) patients had eGFR < 60 mL/min × 1.73 m2. Nephrolithiasis was present in 27 (30%) patients. Compared with the controls, patients had lower Alb-Ca (8.9 ± 0.5 vs. 9.5 ± 0.3 mg/dL, P 0.0001) and a higher rate of kidney stones, mostly asymptomatic [27/90 (30%) vs 7/142 (5%), P < 0.0001, odd ratio 8.2 (3.4-19.9)]. Fifty-seven patients had ≥ four serum Ca2+ determinations during follow-up. Forty (70.2) patients had values within the target range in > 50% of cases, 18 in > 75%, and only 2 in 100%. Two patients never had values in the target range.
Conclusions: Treatment of chronic PO-HypoPT with calcium and activated vitamin D metabolites is suboptimal and associated with an increased risk of renal complications.
Keywords: Activated vitamin D; Calcitriol; Calcium; Nephrolithiasis.