Vincent Biourge

Improvement in insulin resistance and reduction in plasma inflammatory adipokines after weight loss in obese dogs

Obesity is now a major disease of dogs, predisposing to numerous disorders including diabetes mellitus. Adipocytes are active endocrine cells, and human obesity is characterized by derangements in inflammatory adipokine production. However, it is unclear as to whether similar changes occur in dogs. The purpose of the current study was to assess insulin sensitivity and inflammatory adipokine profiles in dogs with naturally occurring obesity and to investigate the effect of subsequent weight loss. Twenty-six overweight dogs were studied, representing a range of breeds and both sexes. All dogs underwent a weight loss program involving diet and exercise. Body fat mass was measured by dual-energy x-ray absorptiometry; plasma concentrations of insulin, glucose, and a panel of inflammatory adipokines (including acute-phase proteins, cytokines, and chemokines) were also analyzed. Body fat mass before weight loss was positively correlated with both plasma insulin concentrations (Kendall tau=0.30, P=0.044) and insulin:glucose ratio (Kendall tau=0.36, P=0.022), and both decreased after weight loss (P=0.0037 and 0.0063, respectively). Weight loss also led to notable decreases in plasma tumor necrosis factor-alpha (TNF-alpha), haptoglobin, and C-reactive protein concentrations (P<0.05 for all), suggesting improvement of a subclinical inflammatory state associated with obesity. This study has demonstrated that in obese dogs, insulin resistance correlates with degree of adiposity, and weight loss improves insulin sensitivity. Concurrent decreases in TNF-alpha and adipose tissue mass suggest that in dogs, as in humans, this adipokine may be implicated in the insulin resistance of obesity.

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.

Obesity-related metabolic dysfunction in dogs: a comparison with human metabolic syndrome

BackgroundRecently, metabolic syndrome (MS) has gained attention in human metabolic medicine given its associations with development of type 2 diabetes mellitus and cardiovascular disease. Canine obesity is associated with the development of insulin resistance, dyslipidaemia, and mild hypertension, but the authors are not aware of any existing studies examining the existence or prevalence of MS in obese dogs.Thirty-five obese dogs were assessed before and after weight loss (median percentage loss 29%, range 10-44%). The diagnostic criteria of the International Diabetes Federation were modified in order to define canine obesity-related metabolic dysfunction (ORMD), which included a measure of adiposity (using a 9-point body condition score [BCS]), systolic blood pressure, fasting plasma cholesterol, plasma triglyceride, and fasting plasma glucose. By way of comparison, total body fat mass was measured by dual-energy X-ray absorptiometry, whilst total adiponectin, fasting insulin, and high-sensitivity C-reactive protein (hsCRP) were measured using validated assays.ResultsSystolic blood pressure (P = 0.008), cholesterol (P = 0.003), triglyceride (P = 0.018), and fasting insulin (P < 0.001) all decreased after weight loss, whilst plasma total adiponectin increased (P = 0.001). However, hsCRP did not change with weight loss. Prior to weight loss, 7 dogs were defined as having ORMD, and there was no difference in total fat mass between these dogs and those who did not meet the criteria for ORMD. However, plasma adiponectin concentration was less (P = 0.031), and plasma insulin concentration was greater (P = 0.030) in ORMD dogs.ConclusionsIn this study, approximately 20% of obese dogs suffer from ORMD, and this is characterized by hypoadiponectinaemia and hyperinsulinaemia. These studies can form the basis of further investigations to determine path genetic mechanisms and the health significance for dogs, in terms of disease associations and outcomes of weight loss.

Effects of weight loss in obese cats on biochemical analytes related to inflammation and glucose homeostasis.

The aim of the current study was to measure circulating metabolic and inflammation-related biochemical analytes in obese cats before and after weight loss. Thirty-seven overweight neutered cats were studied, median body weight 6.85 kg (range, 4.70 to 10.30 kg), representing a range of ages and both sexes. An individualized weight-loss program was devised for each cat and monitored until completion. Body fat mass was determined by dual-energy x-ray absorptiometry, whereas plasma concentrations of acute-phase proteins (APPs; eg, haptoglobin and serum amyloid A), hormones (eg, insulin, IGF-1, and adiponectin), and enzymes (eg, butyrylcholinesterase and paraoxonase type 1 [PON-1]) associated with inflammation and metabolic compounds (eg, glucose) were also measured. No significant changes were found in APPs after weight loss (P > 0.3), but significant increases in plasma adiponectin (P = 0.021) and IGF-1 (P = 0.036) were seen, whereas insulin (P < 0.001) and homeostasis model assessment (P = 0.005) decreased significantly. Plasma concentrations before weight loss of PON-1 (P = 0.004), adiponectin (P = 0.02), and IGF-1 (P = 0.048) were less in cats that failed to complete weight loss than cats that were successful, whereas glucose concentration was greater. Finally, multivariable linear regression analysis showed that lean tissue loss during weight management was associated with percentage weight loss (greater weight loss, greater lean tissue loss; R = 0.71, P < 0.001) and plasma adiponectin concentration before weight loss (lesser adiponectin, more lean tissue loss; R = -0.52, P = 0.023). In conclusion, various metabolic abnormalities occur in feline obesity, and these can be linked to outcomes of weight-loss programs. The changes that occur with weight loss suggest an improved metabolic status.

Imprecision when using measuring cups to weigh out extruded dry kibbled food

Many pet cats and dogs are fed dry extruded kibbled food by measuring cup, yet the precision and accuracy of this feeding strategy is not known. Over 12 studies, we assessed precision and accuracy of weighing out food portions, of various dry kibbled foods, by measuring cup. Poor precision was noted in all studies, with intra- and inter-subject coefficients of variation ranging from 2 to 13% and 2 to 28% respectively. Variable accuracy was also noted, which ranged from an 18% under-estimate to an 80% over-estimate in portion size. No specific factors were associated with imprecision, but the degree of inaccuracy was negatively associated with portion size (R = -0.67, p = 0.022), and positively associated with the number of subjects participating in the study (R = 0.60, p = 0.048). This is the first study to document imprecision and inaccuracy of using measuring cups to estimate portions of extruded dry kibbled food. Over time, such errors could contribute to insidious weight gain in companion animals, potentially contributing to the development of obesity. Imprecision in measuring food portions could also contribute to failure of weight management programmes for obese animals.

Long-term follow-up after weight management in obese dogs: The role of diet in preventing regain

Regain after weight loss is widely reported in humans, but there is little information on this phenomenon in dogs. The current study aim was to determine long-term success of a weight loss regime and those factors linked with regain. Thirty-three obese dogs, that had successfully lost weight, were included, all enrolled between December 2004 and May 2009. After weight loss, dogs were switched to a maintenance regime and follow-up weight checks were performed periodically. A review of cases that had completed their weight programme was held during the summer of 2010 and a follow-up check was subsequently conducted, where dogs were reweighed and information was collected on current feeding practices. Median duration of follow-up was 640 days (119-1828 days). Fourteen dogs (42%) maintained weight, 3 (9%) lost >5% additional weight, and 16 (48%) gained >5% weight. Dogs fed a purpose-formulated weight loss diet regained less weight than those switched onto a standard maintenance diet (P=0.0016). Energy intake at the time of follow-up was significantly higher in those dogs fed a standard maintenance diet, compared with those that had remained on a purpose-formulated weight loss diet (P=0.017). These results suggest that weight regain occurs in about half of dogs after successful weight loss. Long-term use of a purpose-formulated weight management diet can significantly limit regain in the follow-up period, likely by limiting food intake.

Periodontal Health Status in a Colony of 109 Cats

Periodontal disease has not been well characterized in the cat, and it is not known if feline tooth resorptions (TR) are equivalent to those observed in humans and dogs. The aim of this study was to investigate the different patterns of periodontal inflammation in cats, and to evaluate their prevalence in a standardized healthy population (n=109). Particular emphasis was placed on the potential associations between TR and periodontal parameters, as well as the influence of potential risk factors (including breed, sex, and age). A single complete periodontal examination was performed, including periodontal probing of each tooth and exploration of the tooth surface using a dental explorer; at least 10 radiographs were taken for each cat. Missing teeth with radiographic evidence of root apices were present in 34.0 % of cats. Periodontal disease was common, and 13.0 % of cats had aggressive periodontitis. All of the cats had some form of periodontal inflammation, and only 4.0 % of cats were free from gingival inflammation. Moderate to severe gingivitis was present in 13.0 % of teeth. Dental furcation exposure was present in 18.0 % of all multi-rooted teeth. Periodontal bone loss was observed in 31.2 % of teeth, with the majority (98.2 %) of all cats having some form of periodontal bone loss. Breed effects were identified for some variables. Eight of 14 periodontal variables were statistically correlated with Type 1 TR. Two of 14 variables (and age) were statistically correlated with Type 2 TR. In conclusion, the cats of this colony had a wide range of periodontal inflammation, including aggressive periodontitis. Type 1 TR and Type 2 TR were identified to be two significantly different manifestations of TR, with a strong association between Type 1 TR and periodontal disease.

Postprandial response of plasma insulin, amylin and acylated ghrelin to various test meals in lean and obese cats

The propensity of diets of different composition to promote obesity is a current topic in feline medicine. The effects of three meals with different protein:fat ratios on hormones (insulin, acylated ghrelin and amylin) involved in the control of food intake and glucose metabolism were compared. Five lean (two females and three males, 28.6 (sd 3.4) % body fat mass (BFM), mean body weight (BW) 4590 g) and five obese (two females and three males, 37.1 (sd 4.1) % BFM, mean BW 4670 g) adult cats were studied. Only BFM differed significantly between obese and lean cats. The cats were fed a high-protein (HP), a high-fat and a high-carbohydrate diet in a randomised cross-over design. Food intake did not differ between cats fed on the different diets, but obese cats consumed significantly more energy, expressed as per kg fat-free mass, than lean cats. After a 6-week adaptation period, a test meal was given and blood samples were collected before and 0, 30, 60 and 100 min after the meal. Baseline concentrations of glucose, amylin and acylated ghrelin were higher in obese cats than in lean cats, and obese cats showed the highest postprandial responses of glucose and amylin. The HP diet led to higher postprandial amylin concentrations than the other diets, indicating a possible effect of amino acids on beta-cell secretion. Postprandial ghrelin concentrations were unaffected by diet composition. The relationship between insulin, amylin and ghrelin secretion and their relevant roles in food intake and glucose metabolism in cats require further study.

Dietary NaCl Does Not Affect Blood Pressure in Healthy Cats

The purpose of this study was to assess the effects of dietary salt intake on systolic blood pressure, water intake, urine output, and urine concentration in cats. Ten healthy young adult cats (mean age 2.5 years) were randomly divided into 2 groups and fed either a control diet (0.46% Na and 1.33% Cl on a dry matter [DM] basis) or a diet with a moderately increased salt content (1.02% Na and 2.02% Cl on a DM basis) for 2 weeks. After a 1-week wash-out period, each group was switched to the opposite diet for 2 weeks. During each 2-week study period, food and water intake, urine volume, urine specific gravity, and urine osmolality were measured daily. Systolic blood pressure (calculated as the mean of 5 readings measured with a Doppler flow detector) was assessed twice daily. No significant effect of diet composition was found on systolic blood pressure, and blood pressure measurements remained within reference limits throughout the study in all 10 cats. However, animals fed the higher salt diet had significantly increased water intake and urine osmolality, and significantly decreased urine specific gravity in comparison to animals fed the control diet. Examination of results of this preliminary study suggests that feeding a diet with moderately increased salt content increases water intake and causes diuresis without increasing systolic blood pressure in healthy adult young cats.

A Randomized, Open‐Label, Positively‐Controlled Field Trial of a Hydrolyzed Protein Diet in Dogs with Chronic Small Bowel Enteropathy

BACKGROUND Hydrolyzed protein diets are commonly used to manage canine chronic enteropathies (CE), but their efficacy has not yet been critically evaluated. HYPOTHESIS A hydrolyzed protein diet is superior to that of a highly digestible (control) diet in the management of CE in dogs. ANIMALS Twenty-six dogs (18 test diet, 8 control diet) referred for investigation and management of naturally occurring chronic small intestinal disease. METHODS Randomized, open-label, positively controlled trial. After a full diagnostic investigation, which included endoscopy, dogs were assigned either to the test diet or control diet on a 2:1 basis (test:control). Cases were re-evaluated 3 times (at approximately 3, 6-12 months, and 3 years). Outcome measures included response of clinical signs (complete, partial, none), change in severity of signs (based upon clinical disease activity index; canine inflammatory bowel disease activity index [CIBDAI]), change in body weight, and need for other therapy. RESULTS There were no significant differences in baseline characteristics (eg, signalment, body weight, and duration of clinical signs), and histopathologic severity between test and control diet groups. However, despite randomization, CIBDAI was significantly higher in the test diet group (P=.013). Most dogs had responded by first evaluation, with no difference between groups (P=.87). However, significantly more dogs on the test diet remained asymptomatic at both the second (P=.0012) and third (P<.001) re-evaluation, and the decrease in CIBDAI was significantly greater (P=.010). CONCLUSIONS AND CLINICAL IMPORTANCE A hydrolyzed protein diet can be highly effective for long-term management of canine chronic small bowel enteropathy.