Association of body weight and body condition with survival in dogs with heart failure

BACKGROUND: Obesity is a risk factor for cardiovascular disease in people, but overweight and obese human heart failure patients have improved survival compared with normal--or underweight controls--the obesity paradox. The purpose of this study was to determine if there is an association of body weight and body condition with survival in dogs with heart failure. HYPOTHESIS: That body condition and changes in body weight are predictors of survival in dogs with heart failure. ANIMALS: One hundred and eight dogs with heart failure (International Small Animal Cardiac Health Council stages 2, 3a, or 3b) secondary to dilated cardiomyopathy or chronic valvular disease. METHODS: Medical records were reviewed, and data regarding initial body weight and body condition score (BCS), subsequent changes in body weight, and treatment were collected. Survival times were determined for dogs that were discharged from the hospital and lived >24 hours. RESULTS: Survival was significantly different between dogs that gained, lost, or maintained body weight over the course of their disease (P= .04), with dogs that gained weight surviving the longest. BCS and medications were not significantly associated with survival time; however, n-3 fatty acid intake was associated with longer survival time (P= .009). CONCLUSIONS AND CLINICAL IMPORTANCE: These results suggest that changes in body weight might be an important consideration in the survival of dogs with heart failure.     

Gut microbiota—a positive contributor in the process of intermittent fasting-mediated obesity control

Historically, intermittent fasting (IF) has been considered as an effective strategy for controlling the weight of athletes before competition. Along with excellent insight into its application in various spaces by numerous studies, increasing IF-mediated positive effects have been reported, including anti-aging, neuroprotection, especially obesity control. Recently, the gut microbiota has been considered as an essential manipulator for host energy metabolism and its structure has been reported to be sensitive to dietary structure and habits, indicating that there is a potential and strong association between IF and gut microbiota. In this paper, we focus on the crosstalk between these symbionts and energy metabolism during IF which hold the promise to optimize host energy metabolism at various physical positions, including adipose tissue, liver and intestines, and further improve milieu internal homeostasis. Moreover, this paper also discusses the positive function of a potential recommendatory strain (Akkermansia muciniphila) based on the observational data for IF-mediated alternated pattern of gut microbiota and a hopefully regulatory pathway (circadian rhythm) for gut microbiota in IF-involved improvement on host energy metabolism. Finally, this review addresses the limitation and perspective originating from these studies, such as the association with tissue-specific bio-clock and single strain research, which may continuously reveal novel viewpoints and mechanisms to understand the energy metabolism and develop new strategies for treating obesity, diabetes, and metabolic disorders.     

Obesity induced changes to plasma adiponectin concentration and cholesterol lipoprotein composition profile in cats

Feline obesity generally results in aberrations to plasma metabolite levels, such as lipid concentrations and lipoprotein composition. This study sought to investigate the resultant effect of obesity on cholesterol lipoprotein composition and circulating adiponectin concentrations in cats. Plasma glucose, lipids (triglyceride, cholesterol and free fatty acid), insulin and adiponectin concentrations, and cholesterol lipoprotein composition were measured and compared between body condition score (BCS) determined normal healthy control and obese cats. Although the obese group demonstrated higher levels of plasma cholesterol, glucose, and triglycerides, as compared to healthy controls, the difference was insignificant thus indicating that the BCS determined obese cats may have been overweight and not morbidly obese. Plasma insulin levels were significantly higher (25–30%) versus healthy control animals thereby possibly hinting at the ensuing emergence of obesity induced insulin resistance. However, the BCS determined obese cat demonstrated a significant reduction (p < 0.05) in plasma adiponectin concentration and a significant increase (p < 0.05) in LDL-cholesterol % as compared to age matched healthy control animals. This would indicate that changes in plasma adiponectin concentration and cholesterol lipoprotein composition may be good early indicators of obesity in cats.     

Activity and tissue-specific expression of lipases and tumor-necrosis factor alpha in lean and obese cats

Post-heparin plasma activity of lipoprotein lipase (LPL) and hepatic lipase (HL), and fat and muscle activity of LPL were measured in neutered lean and obese cats. Lipoprotein lipase, hormone-sensitive lipase (HSL), and tumor necrosis factor a (TNF) mRNA were measured in muscle and fat tissue with real-time PCR using primers for feline LPL, HSL, and TNF. Lipoprotein lipase plasma and fat activity and fat mRNA levels were significantly lower (50, 80, and 50%, respectively) in obese cats than lean cats, whereas the muscle/fat ratio of LPL was significantly higher in obese compared to lean cats. The activity of HL was not different between the groups. Hormone-sensitive lipase mRNA levels were significantly higher in obese than lean cats. The level of fat TNF also was significantly higher in obese cats than in lean cats, whereas the level in muscle was not different. The lower LPL activity and mRNA expression in fat and the higher LPL and HSL mRNA expression in muscle in obese cats compared to lean cats expectedly favor a redistribution of fatty acids from fat to muscle tissue where they can be deposited or used for energy in times of need. Tumor necrosis factor alpha may regulate this repartitioning process through suppression of adipocyte LPL.     

Dietary energy restriction and successful weight loss in obese client-owned dogs

BACKGROUND: Obesity is the most common nutritional disease in dogs. Although weight loss by dietary caloric energy restriction is successful in experimental studies, there is limited information on success of such programs in client-owned dogs who are obese. Further, no information currently exists on the changes in body composition during weight loss in clinical cases. HYPOTHESIS: Key determinants of outcome of weight loss, including energy allocation and body composition, are influenced by both individual and weight program factors. ANIMALS: Nineteen client-owned dogs with naturally occurring obesity. METHODS: In this prospective clinical study, body composition was quantified by dual-energy X-ray absorptiometry before and after weight loss on an individually tailored program that incorporated a high-protein and moderate-fiber diet. RESULTS: Mean percentage weight loss was 18% (range, 6-29%), and mean rate of weight loss was 0.85% per week (range, 0.35-1.56%). Mean energy allocation required to achieve weight loss was 60% of maintenance energy requirement at target weight (MERTW) (range, 50-82%). Significant dietary noncompliance was reported (mean, 1.0% MERTW; range, 0.0-9.5%). The mean composition of tissue lost was 84: 15:1 (fat : lean : bone mineral content [BMC]). Lean tissue loss was positively associated with overall percentage of weight loss (Pearson correlation coefficient [Rp] = 0.591, P = .008), whereas BMC loss was greater in retrievers compared with other breeds (1.9% +/- 1.16% versus 0.8% +/- 0.44%; P = .008). CONCLUSIONS AND CLINICAL IMPORTANCE: This clinical study demonstrated body composition changes during weight loss in dogs. Conventional programs produced safe weight loss, but marked energy restriction was required and the rate of loss was slower than in experimental studies.     

A high-protein, high-fiber diet designed for weight loss improves satiety in dogs

BACKGROUND: Weight-loss programs for dogs are often hampered by increased begging and scavenging behavior that ensues when food intake is restricted. HYPOTHESIS: A diet formulated to contain a high content of both protein and fiber is more satiating than diets that contain only high fiber or high protein. ANIMALS: Six entire female adult dogs (2 Shetland Sheepdogs, 2 Brittany Spaniels, 2 Labrador Retrievers) participated in the satiety studies; 105 adult female dogs of various breeds and ages were used for the palatability studies. METHODS: Three diets (high protein [103 g/1,000 kcal] high fiber [60 g/1,000 kcal] [HPHF]; high protein [104 g/1,000 kcal] moderate fiber [35 g/1,000 kcal] [HP]; moderate protein [86 g/1,000 kcal] high fiber [87 g/1,000 kcal] [HF]) were tested. Voluntary food intake was measured in 5 sequential crossover studies, and palatability was assessed with food preference tests. RESULTS: Protein digestibility was significantly lower for HF (mean +/- SD; 77.7% +/- 2.52%) than for both HPHF (81.1% +/- 0.96%) and HP (81.1% +/- 1.65%) (P < .001). Short-term food intake (food ingested when offered for 15 minutes every hour for 4 hours) was lower for HPHF than for both HP and HF (P = .038). Medium-term intake (food ingested when offered 3 hours after first meal) was lower for both HPHF (27 +/- 22.2 kcal/kg(0.73)) and HF (41 +/- 6.8 kcal/kg(0.73)) than for HP (57 +/- 18.8 kcal/kg(0.73)) (P = .041). Voluntary food intake 3 hours after feeding a restricted meal (25% daily maintenance energy requirements) was significantly lower on the HPHF diet than on either the HP (-51%, P = .0051) or HF (-47%, P = .014) diets. However, there was no significant difference between the energy intake on the HP and HF diets (7%, P = .37). The HPHF and HP diets had equivalent palatability, and both were more palatable than the HF diet (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The HPHF diet had a satiating effect as evidenced by reduced voluntary intake compared with HP and HF diets, and has the potential to lead to greater compliance in weight-loss programs.     

肿瘤坏死因子-α(TNF-α)与肥胖

肿瘤坏死因子 ( Tumor Necrosis Factor,TNF)包括由活化的单核 /巨噬细胞产生的TNF- α和由活化的 T淋巴细胞产生的 TNF- β两种。二者在细胞来源、相对分子量、等电点、糖含量等方面有很大差别。 TNF-α是一种具有多种生物学活性的细胞因子 ,由 1 40 - 1 5 0个氨基酸残基组成 ,其中有两个反平行β片层 ,每个β片层有 5个β折叠。它由 TNFRI和 TNFRII两种受体组成 ,二者胞内结构区的同源性极低 ( 2 7% ) ,可能启动不同的生物学反应。研究发现TNF- α是与肥胖相关的蛋白质之一 ,对脂肪代谢具有重要调节作用。TNF- α通过抑制进食、增加机体产热量 ;促进脂肪分解、抑制脂肪合成 ;诱导产生瘦素 ;引起胰岛素抑制、抑制前脂肪细胞分化 ;诱导前脂肪细胞及脂肪细胞凋亡等作用调节脂肪代谢和能量平衡。同时 ,TNF- α在肥胖动物或人的脂肪组织中过量表达 ,也会给人和动物机体带来很多副作用     

Plasma leptin concentration in dogs: effects of body condition score, age, gender and breeds

Leptin is a cytokine produced by adipocytes, and plays a key role in the regulation of energy balance. In the present study, we measured plasma leptin concentrations of 166 normal and obese dogs visiting veterinary practices, and clarified the influence of age, gender and breed on plasma leptin levels in dogs. Leptin levels were higher in the dogs with higher body condition scores. There was no noticeable influence of age, gender and breed, but those in optimal puppies and obese Miniature Dachshund tended to be lower than those in corresponding groups. We conclude that plasma leptin is a reliable marker of adiposity in dogs regardless of age, gender and breed variations, and thereby useful as a blood biochemistry test for health examinations and treatment of obesity.     

Dietary polyphenols in lipid metabolism: A role of gut microbiome

Polyphenols are a class of non-essential phytonutrients, which are abundant in fruits and vegetables. Dietary polyphenols or foods rich in polyphenols are widely recommended for metabolic health. Indeed, polyphenols (i.e., catechins, resveratrol, and curcumin) are increasingly recognized as a regulator of lipid metabolism in host. The mechanisms, at least in part, may be highly associated with gut microbiome. This review mainly discussed the beneficial effects of dietary polyphenols on lipid metabolism. The potential mechanisms of gut microbiome are focused on the effect of dietary polyphenols on gut microbiota compositions and how gut microbiota affect polyphenol metabolism. Together, dietary polyphenols may be a useful nutritional strategy for manipulation of lipid metabolism or obesity care.     

ob基因及其表达产物的生物学效应

ob基因自从被克隆后,围绕其表达产物的作用机理和生物学效应进行了大量的研究,最近研究证明Leptin对小鼠大脑发育有重要功能,标志着Leptin的研究进入了一个新的阶段,今后将从单一的营养调控研究转向兼顾神经生物学的研究,更深入研究Leptin作用机理。同时国内外学者从分子领域探究ob基因在畜禽育种上的作用,做了很多的工作,也取得了重要的成果。本文总结了ob基因的重要生物学效应,为理解ob基因的作用机制和进一步研究人类肥胖治疗和提高动物生长繁殖性状水平提供必要的支持。     

Triiodothyronine differentially regulates key metabolic factors in lean and obese cats

The effect of a 2-week administration of 75microg triiodothyronine (T3) on substrate oxidation, heat production, non-esterified fatty acids, and leptin was evaluated in eight lean (three females and five males) and eight obese (five females and three males) age-matched adult neutered cats. In addition, using real-time RT-PCR, expression of muscle and adipose tissue uncoupling proteins (UCP2 and UCP3), deiodinase 1 and 2 (D1; D2), and peroxisome proliferator-activated receptor (PPAR) alpha and gamma and peroxisome-proliferator-activator receptor-gamma co-activator 1alpha (PGC1) was examined. Compared to lean cats, obese cats had increased NEFA, leptin, UCP2, and D1mRNA in muscle and UCP3mRNA levels in fat, but lower heat production, and fat PPARs and PGC1. T3 administration increased thermogenesis and NEFA in lean and obese cats, and adipose tissue PPARgamma in lean cats. It also increased muscle D1 in lean and D2 in obese cats. The increase in muscle D2 was interpreted to be reflective of the reduced serum total T4 concentration following T3 suppression of the pituitary. No effect was seen on leptin, or UCP2 and 3. This shows that T3 regulates thermogenesis but not through changes in uncoupling protein expression. It also indicates that PPARs have an important role in the pathogenesis of obesity in cats.