Serum Concentrations of Insulin-like Growth Factor-1 (IGF-1), 26S Proteasome (26S PSM), and 3-Methylhistidine (3-MH) in Cats with Hypertrophic Cardiomyopathy

Background: Cardiomyopathies not only affect the cardiovascular system but can also have systemic implications. Despite their significance, only a few laboratory parameters are currently used to describe the metabolic effects of cardiomyopathies. This study aimed to explore a potential link between hypertrophic cardiomyopathy (HCM) and serum IGF-1, 26S PSM, and 3-MH concentrations in cats. Materials and Methods: Serum IGF-1, 26S PSM, and 3-MH concentrations were measured using ELISA in cats diagnosed with HCM (n = 27; 13 cats in category B1 + B2 and 14 cats in category C + D) and compared with those of a healthy control group (n = 35). Additionally, these parameters were analyzed in relation to various morphological factors assessed via echocardiography in affected cats. Results: Cats with HCM exhibited elevated median serum IGF-1 and 3-MH concentrations compared to the control group, suggesting metabolic alterations. While 26S PSM levels did not differ significantly, 3-MH concentrations showed a non-significant tendency to higher serum concentrations in cats categorized as C–D than in those classified as B1–B2. Conclusions: These findings suggest a potential interplay between HCM and protein metabolism in cats, highlighting the relevance of metabolic biomarkers in understanding disease progression.