Ovariohysterectomy alters body composition and adipose and skeletal muscle gene expression in cats fed a high-protein or moderate-protein diet.

The objective of this study was to measure changes in body composition, physical activity and adipose and skeletal muscle gene expression of cats fed a high-protein (HP) diet or moderate-protein (MP) diet, following ovariohysterectomy. Eight cats were randomized onto HP or MP diets and were fed those diets for several months prior to baseline. All cats underwent an ovariohysterectomy at baseline (week 0) and were allowed ad libitum access to dietary treatments for 24 weeks. Food intake was measured daily, and BW and body condition score were measured weekly. Blood, adipose and skeletal muscle tissue samples were collected, physical activity was measured, and body composition was determined using DEXA (dual-energy X-ray absorptiometry) at weeks 0, 12 and 24. Caloric intake increased soon after ovariohysterectomy, resulting in increased (P < 0.05) BW at weeks 12 and 24 compared to week 0. Body condition score and body fat percentage increased (P < 0.05) over time. Blood glucose increased (P < 0.05) linearly over time. Non-esterified fatty acids were decreased (P < 0.05) at weeks 12 and 24 compared to week 0. Blood leptin increased (P < 0.05) over time. Total physical activity decreased (P < 0.05) from week 0 to weeks 12 and 24 in all cats. Adipose tissue mRNA abundance of adiponectin, hormone sensitive lipase, toll-like receptor-4, uncoupling protein-2 (UCP2) and vascular endothelial growth factor decreased (P < 0.05) linearly over time, regardless of diet. Skeletal muscle mRNA abundance for glucose transporter-1, hormone sensitive lipase and UCP2 were decreased (P < 0.05), regardless of dietary treatment. Our research noted metabolic changes following ovariohysterectomy that are in agreement with gene expression changes pertaining to lipid metabolism. Feeding cats ad libitum after ovariohysterectomy is inadvisable.