Complications of chronic hypoparathyroidism according to analysis database Russian Registry

BACKGROUND . Chronic hypoparathyroidism (HypoPT) is a relatively rare endocrine disorder. Adequate control of the disease requires the prescription of lifelong multicomponent therapy. Lack of sustained compensation of HypoPT is associated with the development of both early and delayed complications, including functional and structural renal pathology, cataracts, cerebral calcification, cardiac rhythm and/or conduction disorders, and others. AIM . To study the associations of clinical, laboratory and instrumental parameters, as well as the medical therapy, with long-term complications of chronic HypoPT. MATERIALS AND METHODS . The observational, continuous study was based on the data of the Russian Registry of Patients with Chronic Postoperative and Nonsurgical HypoPT; 1776 patients from 81 regions of the Russian Federation were included in the study. RESULTS . In the study population, 26,3% of patients (n=467) had at least one of the HypoPT complications, among them nephrolithiasis/nephromicrolithiasis was diagnosed in 33,4%. Nephrocalcinosis was observed in 10,7% and was more often bilateral (93,5%). In 17,4% of patients there was a significant decrease in GFR, corresponding to CKD stages 3a-5. Cataract was present in 34,7% of patients with chronic HypoPT. Statistically significant associations were found for disease duration with impaired renal filtration function (p<0,001), nephrocalcinosis/nephrolithiasis (p=0,001) and cataract (p<0,001). Patients with impaired renal function had higher serum ionized calcium level (p=0,0071) and lower phosphorus level (p=0,002). Cataract was predominantly diagnosed in patients of older age group (p<0,001), predominant in the presence of hypocalcemia by ionized calcium level (p=0,001). In patients undergoing brain MSCT for neurological symptoms, basal ganglia calcifications were detected in more than half of the cases (56,2%). Brain calcification was associated with younger patient age (p<0,001), hyperphosphatemia (p<0,001), hypomagnesemia (p=0,010). Statistically significant associations were observed between calcification of brain structures and higher doses of alfacalcidol and calcium carbonate (p=0,007). CONCLUSION . The analysis of the database revealed a number of associations between clinical, laboratory and instrumental parameters and long-term complications of HypoPT. The most significant factors in the development of renal pathology and cataracts are the duration of the disease, as well as off-target indicators of calcium-phosphorus metabolism.