Endocrine Abstracts

Despite conventional treatment with oral calcium and active vitamin D, patients with chronic hypoparathyroidism (cHypoPT) can remain not adequately controlled (NAC) and have abnormal biochemistry, disease complications, or symptoms impacting quality of life. A systematic literature review (SLR) was conducted to evaluate the clinical burden for patients with cHypoPT, with an emphasis on patients with NAC disease. This abstract focuses on data related to renal and cardiovascular complications. Key biomedical databases (MEDLINE, EMBASE, MEDLINE In-Process, Cochrane Controlled Register of Trials and Cochrane Database of Systematic Reviews) were searched for pertinent studies from database inception to June 2020. Abstracts from 6 relevant congresses held from January 2017–June 2020 were searched to identify studies not published as full-text journal articles. Publication bibliographies were reviewed to identify additional sources. Eligible studies included adults with cHypoPT and were published in English, with no restrictions on study design or comparator. NAC patients were identified via ≥1 of the following: abnormal biochemistry, renal impairment, persistent symptoms affecting quality of life, and study-specific NAC definitions. Results were described per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Forty-nine studies from 91 publications were included in the SLR. Of these, 21 and 7 publications addressed renal and cardiovascular complications, respectively. Compared with the general population, patients with cHypoPT were at increased risk of renal insufficiency, renal failure, nephrocalcinosis, and nephrolithiasis. Nephrolithiasis and nephrocalcinosis were the most commonly reported renal disorders, with incidence ranging from 1.9%–48% in patients with cHypoPT. Impaired renal function and risk of renal diseases were positively related to cHypoPT duration. In one study, rates of renal disorders were significantly higher in patients with NAC vs adequately controlled (AC) cHypoPT (P<0.01). Patients with cHypoPT were at risk of cardiovascular outcomes including cardiomyopathy, congestive heart failure, ischaemic heart disease, and arrhythmia. Patients with cHypoPT had increased risk of both incident cardiovascular conditions and a composite cardiovascular endpoint compared with patients without cHypoPT (all P<0.05). Longer disease duration was associated with increased risk of cardiovascular complications, independent of disturbances in calcium-phosphate homeostasis. In one study, patients with NAC disease had significantly higher rates of cardiovascular disorders compared with patients who were AC, especially for cardiac artery calcification and QT prolongation. cHypoPT is associated with increased risk of renal and cardiovascular complications. Based on limited published data, patients with NAC disease may experience a higher clinical disease burden than patients whose cHypoPT is controlled.