Short-term obesity results in detrimental metabolic and cardiovascular changes that may not be reversed with weight loss in an obese dog model

Abstract

The time course of metabolic and cardiovascular changes with weight gain and subsequent weight loss has not been elucidated. The goal of the present study was to determine how weight gain, weight loss and altered body fat distribution affected metabolic and cardiovascular changes in an obese dog model. Testing was performed when the dogs were lean (scores 4 -5 on a nine-point scale), after ad libitum feeding for 12 and 32 weeks to promote obesity (.5 score), and after weight loss. Measurements included serum glucose and insulin, plasma leptin, adiponectin and C-reactive protein, echocardiography, flow-mediated dilation and blood pressure. Body fat distribution was assessed by computed tomography. Fasting serum glucose concentrations increased significantly with obesity (P,0·05). Heart rate increased by 22 (SE 5) bpm after 12 weeks of obesity (P¼0·003). Systolic left ventricular free wall thickness increased after 12 weeks of obesity (P¼ 0·002), but decreased after weight loss compared with that observed in the lean phase (P¼ 0·03). Ventricular free wall thickness was more strongly correlated with visceral fat (r 0·6, P¼0·001) than with total body fat (r 0·4, P¼ 0·03) and was not significantly correlated with subcutaneous body fat (r 0·3, P¼ 0·1). The present study provides evidence that metabolic and cardiovascular alterations occur within only 12 weeks of obesity in an obese dog model and are strongly predicted by visceral fat. These results emphasise the importance of obesity prevention, as weight loss did not result in the return of all metabolic indicators to their normal levels. Moreover, systolic cardiac muscle thickness was reduced after weight loss compared with the pre-obesity levels, suggesting possible acute adverse cardiovascular effects.

Metabolic and Immunological Effects of Intermittent Fasting on a Ketogenic Diet Containing Medium-Chain Triglycerides in Healthy Dogs

“…The HOMA insulin resistance scores were also lowest when the dogs were on this feeding regime, which is a reflection of both low fasting glucose and insulin concentrations. Both caloric restriction and a reduction in fat mass improves insulin sensitivity in overweight dogs (83)(84)(85)(86). In our study, intermittently fasted dogs eating a HF diet lost less weight than when intermittently fasted on a LF diet, and yet had lower insulin concentrations.…”

Effect of an extruded pea or rice diet on postprandial insulin and cardiovascular responses in dogs

“…The effects of feeding the pea and rice diets for 12 weeks in obese beagles on body fat, leptin and adiponectin, and cardiovascular parameters are shown in Table . Diet did not result in any significant improvements in cardiovascular parameters even though this laboratory has previously shown that heart rate and systolic left ventricular free wall thickness were increased when dogs became obese compared to when they were normal weight (Adolphe et al., ). Similarly, total, visceral and subcutaneous body fat measured by CT did not differ between diets.…”

Metabolic Effects of Obesity and Its Interaction with Endocrine Diseases

“…20 We are not aware of a similar study in dogs, although 1 investigation using computed tomography showed equal increments of visceral and subcutaneous adipose tissue in dogs during weight gain. 89 …”