Vol.:(0123456789) 1 3 Calcifed Tissue International https://doi.org/10.1007/s00223-018-0405-5 ORIGINAL RESEARCH Prevalence of Chronic Hypoparathyroidism in a Mediterranean Region as Estimated by the Analysis of Anonymous Healthcare Database Luisella Cianferotti 1  · Simone Parri 1  · Giorgio Gronchi 1  · Gemma Marcucci 1  · Cristiana Cipriani 2  · Jessica Pepe 2  · Marco Raglianti 1  · Salvatore Minisola 2  · Maria Luisa Brandi 1 Received: 29 November 2017 / Accepted: 9 February 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract Epidemiological data on prevalence and incidence of chronic hypoparathyroidism are still scarce. This study aimed to estab- lish prevalence of chronic hypoparathyroidism and incidence of surgical hypoparathyroidism using the analysis of electronic anonymous public health care database. Data referred to a 5-year period (2009–2013, Region of Tuscany, Italy, as a sample representative of the whole Mediterranean/European population, estimated mean population: 3,750,000 inhabitants) were retrieved by the analysis of pharmaceutical distribution dataset, containing data related to drugs reimbursed by public health system, hospital discharge and procedures codes, and ICD9 exemption codes for chronic diseases. The application of a spe- cifc algorithm was applied to indirectly identify people with chronic hypoparathyroidism as assuming chronic therapy with active vitamin D metabolites (AVDM). The number of people taking AVDM for a period equal to or longer than 6 months till the end of the study period, with ICD9 exemption code for hypoparathyroidism, and with a disease-related discharge code were identifed. Within this restricted group, patients with chronic kidney disease and osteoporosis were excluded. The indirect estimate of chronic hypoparathyroidism in a European Mediterranean subpopulation by means of the analysis of chronic therapy with AVDM was 27/100,000 inhabitants (female:male ratio = 2.2:1), with a mean age of 63.5 ± 16.7 years. The risk of developing hypoparathyroidism after neck surgery was 1.5%. While the epidemiological approaches based on disease code and hospital discharge code greatly underestimates the prevalence of hypoparathyroidism, the indirect estimate of this disease through the analysis of prescriptions of AVDM in a European region is in line with the results of studies performed in other regions of the world. Keywords Epidemiology · Chronic hypoparathyroidism · Parathyroid hormone · PTH1-84 · Calcitriol Introduction Chronic hypoparathyroidism refers to a group of disorders characterized by the consequences of the lack of parathy- roid hormone action and requiring chronic treatment with calcium salts and active vitamin D metabolites for more than 6 months. The unintentional surgical damage of the parathyroids is the most common form, while autoimmune or genetically determined hypoparathyroidism, isolated or within complex syndromes, is overall considered a rare dis- ease. In recent years, a decrease in the risk of developing permanent hypoparathyroidism after neck surgery has been observed because of increasing surgical expertise, while rare forms once defned as idiopathic are more often recognized and genetically diagnosed with respect to the past, because of better tools in molecular diagnosis [1]. Data on the global epidemiology of this disease are still incomplete and are derived from non-anonymous databases or are restricted to the surgical form of the disease [2, 3]. Recently, a phase 3 randomized, placebo-controlled, mul- ticenter study employing subcutaneous PTH 1-84, formerly used as anabolic therapy for severe osteoporosis, has shown that in patients with chronic hypoparathyroidism this drug is efective in reducing the requirement of calcium and active vitamin D, and it is well tolerated overall [4]. Hence, PTH 1-84 has been reintroduced frst in the United States, and * Maria Luisa Brandi marialuisa.brandi@unif.it 1 Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy 2 Department of Internal Medicine and Medical Disciplines, “Sapienza”, Rome University, Rome, Italy