Endocrine Abstracts

PTH increases calcium uptake from bone, tubular calcium reabsorption and renal phosphate excretion, and by stimulating 1α-OH vitamin D hydroxylase in the kidney increases production of 1,25(OH)2D.

Aim: To differentiate and characterize the various diseases associated with an increase in PTH in the material of the Endocrinology Clinic, Sofiamed University Hospital for 3 years.

Material: 167 patients with elevated PTH were examined, 145 (87.3%) women and 21 (12.7%) men, with an average age of 62.01±12.73 years (36-85 years). Patients are divided into two groups: 1. with Primary Hyperparathyroidism (PHPT), n-77; 2. with Secondary Hyperparathyroidism (SHPT), consisting of three subgroups - 2.1. with vitamin D deficiency (n-31) 2.2. with CKD stage 3-4 (n-39); 2.3. with CKD stage 5 (n-20).

Methods: Standard biochemical and hormonal studies of the mineral exchange, neckultrasonography, Spect-CT and fine needle puncture biopsy in 23% (38/167) of the patients.

Results: The oldest were the patients with SHPT with CKD pre-dialysis, and the youngest were the CKD patients on chroniodialysis compared to the other groups, P<0.001. The serum calcium was significantly higher in patients with PHPT, P<0.001. The serum level of phosphorus was significantly lowest in patients with PHPT and significantly highest in patients with SHPT on chroniodialysis, P<0.001. The same group also had a significantly higher level of alkaline phosphatase compared to patients with PHPT, P<0.001. PTH was significantly higher in patients with SHPT on chroniodialysis, P<0.001, and patients with PHPT had a significantly higher level of PTH only against patients with vitamin D deficiency, P<0.001. In chronodialysis SHPT group, eGFR was significantly lowest vs the other groups, P<0.001. There is a significant direct inverse relationship between the levels of 25(OH)D and PTH in patients with SHPT with CKD pre-dialysis and vitamin D deficiency. There is no dependence of PTH on the level of 25(OH)D in the other two groups - with PHPT and with SHPT of chroniodialysis due to the non-participation of vitamin D in the pathogenesis of both diseases. A significant correlation of eGFR/PTH is present in patients with CKD pre-dialysis, and it is absent in patients with PHPT and group with vitamin D deficiency.

Conclusion: Hyperparathyroidism requires complex investigations carried out by a highly specialized team with sufficient experience for correct diagnostic and subsequent therapeutic assessment.