Weight Gain in Gonadectomized Normal and Lipoprotein Lipase–Deficient Male Domestic Cats Results from Increased Food Intake and Not Decreased Energy Expenditure

Abstract

Gonadectomy predisposes domestic cats to undesired body weight gain and obesity. The disturbance responsible for this disregulation of energy balance has not been clearly identified. Energy intake and expenditure, body composition and plasma concentrations of leptin, insulin, glucose and triacylglycerol were determined during a 36-wk period in adult male (2-5 y) gonadectomized (n = 8) and intact (n = 8) normal cats and gonadectomized (n = 8) and intact (n = 8) lipoprotein lipase (LPL)-deficient cats. Cats were housed individually in temperature- and light-controlled rooms and continuously provided a commercial dry-type diet. In normal and LPL-deficient cats, body weight increased (P < 0.05) after gonadectomy by 27 to 29%, mostly as a result of fat accretion. There was a rapid increase (P < 0.05) in food intake of approximately 12% after gonadectomy of normal and LPL-deficient cats. The metabolic rate (kJ.kg(-1).d(-1)), determined in normal intact (319 +/- 20, n = 5) and gonadectomized (332 +/- 36, n = 5) cats, did not differ after gonadectomy. After gonadectomy, plasma concentrations of glucose and triacylglycerol did not change, whereas plasma insulin and leptin concentrations increased (P < 0.05), but not coincidentally with body weight gain. A stair-step increase in energy intake, and not decreased energy expenditure, appears to drive the weight gain associated with gonadectomy. Body fat mass appears to increase until the energy intake supports no further expansion. Adiposity signaling through insulin or leptin does not appear to mediate the energy intake effect. LPL deficiency did not preclude development of the overweight body condition. Therefore, gonadectomy-induced weight gain in cats is not a result of changed adipose LPL activity, as previously suggested.

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

“…Other researchers have noted that ovariohysterectomized or neutered cats have increased insulin and leptin concentrations, with no change in glucose or TG concentrations (compared to intact cats) (Fettman et al, 1997;Kanchuk et al, 2003). In the current study, food-restricted glucose concentrations increased from week 0 to 24, suggesting decreased insulin sensitivity with weight gain; however, food-restricted blood insulin concentrations did not change over time.…”

“…Food intake and BW increased in all cats following ovariohysterectomy, as has been noted in other studies (Fettman et al, 1997;Harper et al, 2001;Kanchuk et al, 2003;Nguyen et al, 2004;Backus et al, 2007;Cave et al, 2007;Belsito et al, 2009). Earlier research has indicated that an estimated 20% to 30% reduction in food intake is needed to maintain BW of neutered cats (Flynn et al, 1996;Root et al, 1996;Belsito et al, 2009).…”

“…Glucose concentrations reported by Szabo et al (2000) were similar to those measured in the current study. Kanchuk et al (2003) reported increased insulin concentrations of neutered male v. intact male cats; however, changes over time within the neutered males were not statistically analyzed. In the current study, food-restricted TG concentrations increased in HP cats by week 24 following ovariohysterectomy.…”

“…In a review of physical activity in animal models, Tou and Wade (2002) suggested that decreases in physical activity were in response to, rather than the cause of, increased BW. Researchers have reported that BW gains following ovariohysterectomy were due to increased food intake and not decreased energy expenditure (Flynn et al, 1996;Kanchuk Data reported as means 6 s.d. *Linear effect of week (P , 0.05).…”

Association of Obesity with Serum Leptin, Adiponectin, and Serotonin and Gut Microflora in Beagle Dogs

“…If pets weigh 20–30% more than their ideal body weight, they are classified as obese 1. Obesity in dog is associated with several health conditions including insulin resistance, pancreatitis, cruciate ligament rupture, and respiratory distress 2, 3. Bioactive peptides such as leptin, adiponectin, and pro‐inflammatory cytokines secreted from the adipose tissue are called adipokines 4.…”