Increased insulin-like growth factor 1 concentrations in a population of non-diabetic cats with chronic kidney disease

J.P. REY AMUNATEGUI, E. MOLINA, G. POMPILI, J. MAS; PIGNATARO OP; MICELI DD

Barcelona

Congreso; ECVIM CONGRESS; 2023

Hypersomatotropism (HST) is increasingly recognized as a prevalent endocrinopathy in cats, especially associated with diabetes mellitus (DM). Diabetic cats with HST have higher serum concentrations of creatinine than diabetic cats without HST. In humans, HST is also associated with different comorbidities and most cases do not develop overt DM. The aim of the study was to evaluate circulating insulin-like growth factor 1 (IGF-1) in non-diabetic cats with chronic kidney disease (CKD) and to screen this population for the presence of HST. In this prospective study, one hundred cats diagnosed with CKD at referral centers between June 2021 and March 2023 were included. Serum IGF-1 was measured as part of the routine tests for CKD. The diagnosis of CKD was based on history, physical exam, systolic blood pressure, clinicopathological findings and renal ultrasonography. The CKD staging was made according to IRIS (International Renal Interest Society) guidelines. Ninety cats were Domestic Short-Hair, 7 Siamese, 1 Bengal, 1 Burmese and 1 Persian. Fifty-two cats were spayed female and 48 cats were neutered male; median age was 10 years (range 4-20 years); median body weight was 3.6 Kg (range 1.9-8 Kg). Median serum IGF-1 concentrations were 486 ng/ml (range 34-1456 ng/ml). Median serum IGF-1 concentrations of cats with stage 1 (n=8), 2 (n=58), 3 (n=24) and 4 (n=10) of CKD were 257 ng/ml (range 58-918 ng/ml), 476 ng/ml (range 34-1456 ng/ml), 597 ng/ml (range 123-1055 ng/ml), 571 ng/ml (range 123-948 ng/ml), respectively. There was no correlation between serum IGF-1 concentrations and creatinine (r= 0.16, P=0.09). Four out of 100 cats had IGF-1 concentrations >1000 ng/ml, resulting in a 4% (95% confidence interval 1.1-9.9%) HST prevalence rate in non-diabetic cats with CKD. Twelve cats (12%) had IGF-1 concentrations between 800 and 1000 ng/ml. Intracranial imaging was performed in the four cats with IGF-1 concentrations >1000 ng/ml and pituitary enlargement was detected in 1/4 cases on computed tomography. Three of these 4 cats had phenotypic changes consistent with acromegaly: prognathia inferior (3/3), broad facial features (3/3), abdominal enlargement (1/3) and broadening of paws (1/3). The most common ultrasound findings were bilateral chronic nephropathy (4/4) and adrenomegaly (2/4). A proportion of 4% of non-diabetic cats with CKD from referral centers had serum IGF-1 concentration compatible with HST. This study highlights the relevance of screening different sub-populations of non-diabetic cats to increase the recognition of HST and to determine the significance of this disease in the cat population.