Body fat distribution and metabolic consequences — Examination opportunities in dogs

Abstract

The relationship between metabolic disorders and the distribution of fat in different body regions is not clearly understood in humans. The aim of this study was to develop a suitable method for assessing the regional distribution of fat deposits and their metabolic effects in dogs. Twenty-five dogs were subjected to computed tomographic (CT) imaging and blood sampling in order to characterise their metabolic status. The different fat areas were measured on a cross-sectional scan, and the animals' metabolic status was evaluated by measuring fasting glucose, insulin and leptin levels. The volume of visceral adipose tissue is the main determinant of leptin levels. The correlation of visceral fat volume and leptin concentration was found to be independent of insulin levels or the degree of insulin resistance. There was a positive correlation between the visceral to subcutaneous fat volume ratio and serum insulin concentration, and a similar trend was observed in the relationship of fat ratio and insulin resistance. The distribution of body fat essentially influences the metabolic parameters in dogs, but the effects of adiposity differ between humans and dogs. The findings can facilitate a possible extrapolation of results from animal studies to humans with regard to the metabolic consequences of different obesity types. Key words: Leptin, insulin resistance, abdominal fat, computed tomographyObesity is a growing problem in companion animals just like in humans. The development of insulin resistance, dyslipidaemia and other metabolic problems appear to be more closely related to the regional distribution of body fat than simply to adiposity or body weight. Even though the phenotypes of human obesity that represent specific risk factors for metabolic disorders have not been reported in dogs, differences in the metabolic effects of increased visceral or

Adipose tissue macrophages in non-rodent mammals: a comparative study

“…This allows the flow cytometry analysis of ATMs isolated from biopsy samples and can expand the possible tools for studying ATMs in the context of metabolic diseases. Since obesity and diabetes is frequent in feline and canine patients at veterinary clinics (Müller et al 2014), the further study of ATMs in these species might be a novel path by which to study the metabolic regulatory role of ATMs in non-rodent mammals.…”

“…Canine and feline specimens were collected as biopsy samples during surgical interventions performed at veterinary clinics by isolating adipose tissue from the falciform ligament and the greater omentum, respectively. The body condition score (BCS) was used to cluster the feline (Bjornvad et al 2011) and the canine (Müller et al 2014) samples into normal and obese categories. Three cats and five dogs were normal (BCS5 for cats, BCS3 for dogs); three cats and four dogs were obese (BCS7 for cats and BCS5 for dogs).…”

“…Body condition and clinical history, plus blood glucose and insulin levels, were recorded for each animal. Blood samples were obtained from the cephalic vein and fasted glucose and insulin levels measured as described previously (Müller et al 2014). Sample collections were approved by the local authorities and the owners of the animals.…”

Compartmental fat distribution in the abdomen of dogs relative to overall body fat composition

“…Obesity is the leading form of malnutrition in dogs, contributing to the pathogenesis of many cardiovascular, metabolic and orthopaedic diseases [1][2][3][4][5][6][7]. Further, there is a growing weight of evidence that fat distribution between the visceral and subcutaneous compartments may influence adipokine, insulin and cytokine regulation, and this is related to the development of obesity-related diseases [2,[6][7][8][9]. Validating non-invasive, objective and practical means of quantifying fat content and distribution is an essential step in further understanding their effects on the development and outcome of fat-related diseases.…”

“…Computed tomography (CT) has overcome many of the limitations encountered by DXA and allows body fat content and distribution to be accurately assessed in dogs [7,[17][18][19][20]. Computed tomography offers several advantages over DXA analysis due to its rapid acquisition time, improved spatial and contrast resolution, ability to view structures in three dimensions, and ability to assign a quantitative value to tissues of different attenuation (Hounsfield units).…”