Increased Risk of Renal Complications in Patients with Chronic Postsurgical Hypoparathyroidism Treated with Conventional Therapy

Presentation Number: MON 341
Date of Presentation: April 3rd, 2017

Antonella Meola*1, Filomena Cetani1, Edda Vignali1, Giovanni Guglielmi2, Irene Donato3, Antonio Matrone4, Rossella Elisei5 and Claudio Marcocci6
1Endocrine Unit 2, University of Pisa, Pisa-ITALY, Pisa, 2Deparatment of Translational Research and New Technologies in Medicine, Pisa, 3Department of Translational Research and New Technologies in Medicine, Pisa, 4Endocrine Unit 1, University of Pisa, Pisa-ITALY, Pisa, ITALY, 5University of Pisa, Pisa, Italy, Pisa, Italy, 6Department of Clinical and Experimenta Medicine, Pisa, Italy

Abstract

The conventional treatment of chronic hypoparathyroidism with calcium and active vitamin D metabolites exposes patients to the risk of renal complications, due to the lacking action of PTH at the renal tubule. We evaluated 90 patients (68 females and 22 males; age: 51.8±14.1 yrs) with chronic postsurgical hypoparathyroidism diagnosed since at least 3 years. All patients were treated with calcitriol (0.87 ± 0.40 μg/day), 35 (39%) were also taking calcium supplements (1.08 ± 0.75 g/day) and 2 thiazide diuretics. Total albumin-corrected (Alb-Ca) and ionized serum calcium, phosphorus, creatinine, PTH, 25(OH)vitamin D, and 24-hour urinary calcium were measured; renal ultrasound was also performed. A group of 142 healthy Hospital employers, matched for age and sex, undergoing routine medical evaluation, which included Alb-Ca, creatinine and renal ultrasound, was used as control. Mean levels of Alb-Ca and ionized calcium were in the normal range [1.14±0.07 mmol/L (range 0.91 to 1.29) and 8.9±0.49 mg/dL (7.5-10.1), respectively], but 39 (43.3%) patients had values that did not met the range recommended by the recent guidelines of the European Society of Endocrinology (ESE) (1.05-1.15 mmol/L for ionized calcium and 8.4-9.2 mg/dl). When all available serum calcium measurement performed prior to the present evaluation were taken into account for each patients (n=78 with at least 3 determinations, mean 5), we found that only 9 (11.5%) patients had all values within the recommended ESE range, and a large proportion of patients (32, 41.0%) had values ≥ the upper recommended value. The mean phosphorus levels [3.64±0.68 mg /dL (2.2-5.9)] and serum creatinine [0.9±0.2 mg/dL (0.58 to 2.1)] were in the normal range, but 7 (7.7%) patients had elevated values of phosphorus and 22 (24.4%) of creatinine. The serum calcium-phosphate product was normal in all patients (<55mg2/dl2). Increased 24-hour urinary calcium excretion (>300/dL mg in men and >250 mg/dL in females) was found in 44 (54%) patients. Kidney stones, mostly asymptomatic, were detected at ultrasound in 27 (30%) patients. Compared to the controls, patients had statistically significant lower mean Alb-Ca (p <0.0001), higher mean serum creatinine (p=0.0008) and greater prevalence of kidney stones [27/90 vs 7/142, p <0.0001, OR: 8.2 (3.4-19.9)]. In conclusion, the results of the present study indicate that the conventional treatment of chronic postsurgical hypoparathyroidism is suboptimal and associated with an increased risk of renal complications and suggest the need for careful monitoring of treatment, as recommended by the ESE guidelines.

 

Nothing to Disclose: AM, FC, EV, GG, ID, AM, RE, CM