Relationship of Body Size to Metabolic Markers and Left Ventricular Hypertrophy in Cats

BACKGROUND Cats with hypertrophic cardiomyopathy (HCM) are larger and have higher insulin-like growth factor-1 (IGF-1) concentrations than cats without HCM. HYPOTHESIS/OBJECTIVES The aim of this study was to assess echocardiographic findings in a colony of adult cats to determine the relationship between early growth and left ventricular hypertrophy (LVH). ANIMALS Twenty-eight neutered adult cats (20 males, 8 females) from a colony ≥ 3 years of age for which growth curves were available. METHODS Case-control study. Physical examination and echocardiography were performed, and body weight, body condition score (BCS), and head length and width were measured. Circulating glucose, insulin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and IGF-1 concentrations were measured and growth data were collected. Stepwise multivariate analyses were performed. RESULTS Mean age was 5.2 ± 1.1 years. Current BCSs ranged from 4 to 9 (median, 6) and mean body weight was 4.88 ± 1.29 kg. Variation in body weight was apparent by 6 (mean = 3.26 ± 0.80 kg) and 12 months of age (mean = 4.02 ± 1.02 kg). Cardiac abnormalities included a cardiac murmur (n = 7; 24%), gallop (n = 3; 10%), and arrhythmia (n = 1; 4%). Fourteen of 28 cats (50%) had echocardiographic evidence of LVH. Head width (P = .017), body weight (P < .001), NT-proBNP (P = .023), and IGF-1 (P = .013-.022) were significantly associated with selected measures of LVH. CONCLUSIONS AND CLINICAL IMPORTANCE Potential associations between body size, IGF-1, LVH, and HCM warrant future prospective studies.