Association of Insulin Resistance and Ectopic Fat Accumulation with HOMA Indices: A Single-Centre Observational Study

Purpose: The aim of this study was to investigate the relationship between non-alcoholic fatty liver disease (NAFLD), non-alcoholic fatty pancreas (or pancreatic) disease (NAFPD) and HOMA indices in obese patients without a diagnosis of diabetes mellitus, using ultrasound (US) as a common non-invasive diagnostic tool during routine examinations. Methods: In this single-centre, retrospective study, the records of patients who applied to the obesity outpatient clinic in 2023 were reviewed. Digital records were scanned and patients with abdominal ultrasound reports indicating age, gender, body mass index(BMI), fasting plasma glucose, fasting plasma glucose, C-peptide level and degree of pancreatic and hepatic steatosis were included in the study. Patients with known chronic disease or diabetes mellitus and patients with specific drug use were excluded from the study. Homa indices were calculated using fasting plasma glucose and C-peptide levels. Results: A total of 62 patients were included. Body mass index was 39.1, 91% had NAFLD and 82% had NAFPD. There was a significant positive correlation between BMI and NAFLD and NAFPD. HOMA scores revealed a statistically significant impact of NAFLD on insulin resistance (HOMA-IR) and insulin sensitivity (HOMA-S) but not on beta-cell function (HOMA-B). No significant effect of NAFPD on HOMA scores was observed. Conclusion: The findings underline the association between NAFLD and insulin resistance and highlight the metabolic burden of ectopic fat deposition in obese patients. In contrast, there was no significant correlation between NAFPD and either insulin resistance or beta-cell function, suggesting that the metabolic impact of pancreatic steatosis may be different. These findings may help to guide clinical strategies for detecting and treating metabolic disorders in obesity.