Analytical Investigation of Serum Insulin Resistance Markers in Obese Cats in South West Nigeria Using Homeostatic Model Assessment

Feline obesity is increasingly prevalent in Nigerian urban companion animal populations and is associated with insulin resistance and a metabolic syndrome-like state, yet analytical characterisation of insulin resistance using validated assessment models in African feline populations is absent from the literature. This study used the homeostatic model assessment of insulin resistance method to analytically investigate serum insulin resistance markers in obese cats presented to veterinary clinics in Lagos and Ogun States, South West Nigeria. Sixty cats classified as obese by body condition score of seven or above and forty ideal-weight cats were enrolled. Fasting serum glucose, insulin, and C-peptide were measured by enzyme-linked immunosorbent assay, and homeostatic model assessment of insulin resistance and homeostatic model assessment of beta-cell function indices were calculated. Obese cats demonstrated significantly higher homeostatic model assessment of insulin resistance scores compared to ideal-weight controls, with 38% of obese cats classified as insulin-resistant using a threshold value derived from the control population. C-peptide was elevated in obese cats, confirming pancreatic beta-cell hypersecretion as a compensatory mechanism. Homeostatic model assessment of beta-cell function was significantly higher in obese non-insulin-resistant cats than insulin-resistant obese cats, suggesting depleted compensatory capacity in the latter group. These analytical findings establish homeostatic model assessment of insulin resistance as a valid tool for feline metabolic screening in South West Nigeria and identify feline insulin resistance as a prevalent and clinically important comorbidity of obesity. Keywords: feline obesity, insulin resistance, homeostatic model assessment, C-peptide, South West Nigeria.