Comorbidity severity index as a new tool for assessment of co-existing diseases in patients with non-alcoholic fatty liver disease at the carbohydrate metabolism disorder background and concomitant subclinical hypothyroidism.

Introduction: Non-alcoholic fatty liver disease (NAFLD) is the most common disease which is characterized by comorbidity. However, no comorbidity index for its assessment has been described yet. The aim of this study was to develop a new index for evaluation of comorbidity in patients with NAFLD.Materials and methods: 226 patients with NAFLD and associated carbohydrate metabolism disorders were examined. Besides, 60 persons with subclinical hypothyroidism, 30 patients with type 2 diabetes mellitus (T2-DM) and 30 NAFLD patients were examined. 30 healthy persons formed the control group. Clinical diagnoses were based on the laboratory tests and liver sonography. A new index of comorbidity has been used. Calculation of comorbidity severity index (ComSI) includes the possible presence of NAFLD, thyroid disorders, abdominal obesity, dyslipidemia, anemia, chronic complications of T2-DM, aggravated anamnesis.Results: The contradiction in the calculation of the well-known comorbidity indices values (CIRS - Cumulative illness rating scale, CCI - Charlson's comorbidity index, Kaplan-Feinstein index) was shown. So, their limited suitability for using in patients with carbohydrate metabolism disorders who have NAFLD was detected. According to our results an increasing of patients' age is associated with the increasing of concomitant diseases number and with deteriorating of the patients' general condition, which is reflected in an increasing of the ComSI value. The increasing of concomitant diseases number is associated not only with the higher ComSI, but also with the number of persons with a severe comorbidity according the ComSI value. Instead, the persons without comorbidity (groups 6, 7, 8) were marked as the patients with mild or moderate disease according the ComSI.Conclusions:The new ComSI index can be used to evaluate the severity of comorbidity in patients with NAFLD.