ECE2022 Poster Presentations Calcium and Bone (68 abstracts)
1University Hospital of Pisa, Department of Clinical and Experimental Medicine, Pisa, Italy; 2University of Pisa, Department of Information Engineering, Pisa, Italy; 3University Hospital of Pisa, Diagnostic and Interventional Radiology Unit, Pisa, Italy; 4University Hospital of Pisa, Endocrine Unit 2, Pisa,
Conventional therapy with oral calcium supplements and activated vitamin D is the most diffuse and available therapy for chronic hypoparathyroidism (HypoPT). This treatment does not replace the lack of PTH and is associated with renal complications. We report the results of a case control study with a prospective design which included 178 adult patients with differentiated thyroid cancer treated with total thyroidectomy with a follow-up longer that 3 years after surgery: 89 with PoHypoPT treated with conventional therapy and 89 without PoHypoPT, matched for age and sex. Both groups were balanced for gender, age, time since thyroidectomy, supplementation with cholecalciferol, dose of levothyroxine and dietary calcium intake. Half of the patients were stable on treatment with calcitriol alone, 45% with calcitriol and calcium carbonate, and 4 with calcium carbonate alone. All patients underwent biochemical tests and renal ultrasound. Twenty-fou- hour urinary calcium, creatinine, sodium, potassium, chloride, sulfate, uric acid, phosphate, oxalate, citrate, volume and Ph were measured. The biochemical control of patients with PoHypoPT was satisfactory, but only one-third of patients was at target according to ESE guidelines. Patients with PoHypoPT, compared with those without PoHypoPT, had significantly lower alb-Ca and PTH and increased serum phosphate, calcium-phosphate product, and 24-h urinary calcium, but there was no difference in estimated GFR. Renal calcifications were detected in 26 (29.2%) patients with PoHypoPT and in 11(12.4%) without. We found a positive association between renal calcification and age (P=0.03) and plasma PTH (P=0.01), but no association with hypercalciuria or other urinary parameters. The median 24-h urinary calcium was significantly higher in patients with PoHypoPT than in those without (248 vs 162 mg, P< 0.01) Urinary calcium in patients with PoHypoPT was positively associated with serum calcium (P <0.001), urinary magnesium (P <0.001), and urinary volume (P= 0.003), and negatively associated with serum albumin (P = 0.025), urinary oxalate (P <0.001) and creatinine (P= 0.008). Our study confirms that conventional therapy in patients with chronic PoHypoPT is suboptimal. 24-h urinary calcium and the rate of renal calcification are higher in patients with chronic PoHypoPT compared with controls. We found no significant difference in renal function (eGFR) between patients with chronic PoHypoPT compared with controls. We found no association between renal calcification and hypercalciuria and/or other urinary stone risk factors. Further prospective studies including a large number of patients would be necessary to better define the risk factor for renal calcifications in patients with PoHypoPT