COMORBIDITIES IN IDIOPATHIC ACHALASIA: A PHENOTYPIC APPROACH TO DRIVE GENETIC ASSOCIATION STUDIES?

Background and aim: There is evidence that idiopathic achalasia has a genetic background and a significant association with several genetic polymorphisms has been indeed described. A given genetic background may affect the phenotypic manifestations of the disease and may account for the presence of contemporary complex diseases. Our aim is to provide a proof of concept study to evaluate comorbidities in achalasia patients, in order to drive future genetic association studies. Material and methods: The study population consisted of 162 patients (69 males, mean age 55 ± 16 years) with proven clinical and instrumental diagnosis of idiopathic achalasia. Gender and age matched subjects selected from the outpatient clinic and referring of esophageal disorders other than achalasia, served as controls. All patients were investigated for the presence of comorbidities (autoimmune diseases, endocrinopathies, hematologic diseases and cardiopathies and neoplasms). Given the high incidence in the general population, type II diabetes, hyperlipidemia and blood hypertension were recorded too. Results: The overall prevalence of comorbidities was similar in achalasia and control patients (62% vs 57%, respectively). Presence of comorbidities did not significantly affect disease’s phenotype as the age of disease onset was similar in achalasia patients with and without comorbidities (46 ± 21 vs. 49 ± 16 years, respectively, p=NS). Blood hypertension, cardiopathies, hyperlipidemia, endocrinological and autoimmune disorders were the most frequently observed comorbidities in achalasia and controls (20 vs 30%, 10 vs 7%, 17% vs 31%, 8% vs 17% and 8% vs 5%, respectively p=all NS). In addition hematological disorders and type II diabetes were similarly prevalent in the two groups. Conclusions: We showed for the first time the type and the frequency of comorbidities in a large series of achalasia patients and we showed that their prevalence is similar to that of a matched control population. Although larger epidemiological studies are needed to confirm our data, our results indicate that the putative genetic factors associated with achalasia are specific for this disease