MON-434 Novel Insight into the Metabolic Shifts in Graves’ Hyperthyroidism: A Study of Acylcarnitine and Lipid Profiles

Abstract Disclosure: M.T. Neset: None. A. Ulvik: None. K. Løvås: None. J. Laupsa-Borge: None. L.E. Breivik: None. A.M. Stokland: None. B. Nedrebø: None. E. Rødahl: None. E.S. Husebye: None. G.Å. Ueland: None. H. Ueland: None. Objective: Graves` disease increases metabolism and leads to net lipid degradation. Circulating acylcarnitines reflect lipid metabolism and state of fatty acid oxidation in the individuals. The aim of this study was to explore the lipid and acylcarnitine profiles in patients with Graves` disease. Methods: Seven lipids/apolipoproteins and 23 acylcarnitines were analyzed in 100 newly diagnosed Graves` disease patients and validated in another 51 patients. Both groups were age- and sex- matched with healthy subjects. Results: Graves` disease patients from the main cohort (87 females, median age 42.5 (17-67) years), had significantly (p < 0.05) higher levels of medium- and long-chain acylcarnitines, and lower levels of short-chain acylcarnitines, compared with healthy subjects. Factor analysis showed that medium- and long-chain acylcarnitines explained most of the differences between the two groups. Serum levels of the seven lipids/apolipoproteins were significantly lower in Graves` disease patients compared to healthy subjects. Patients (n=21) treated with antithyroid drugs for six weeks had acylcarnitines levels closer to healthy subjects, when compared to 79 treatment-naïve hyperthyroid patients. The main findings were confirmed in the validation group. Conclusion: Increased levels of medium- and long-chain acylcarnitines in patients with newly diagnosed Graves` disease may reflect increased heart activity and accelerated catabolism in skeletal muscles. Lower levels of short-chain acylcarnitines point to Graves` disease being a catabolic condition with a shift in energy source from carbohydrates to fat. Presentation: Monday, July 14, 2025