OBJECTIVE-To quantitate insulin sensitivity in lean and obese nondiabetic baboons and examine the underlying cellular/ molecular mechanisms responsible for impaired insulin action to characterize a baboon model of insulin resistance.RESEARCH DESIGN AND METHODS-Twenty baboons received a hyperinsulinemic-euglycemic clamp with skeletal muscle and visceral adipose tissue biopsies at baseline and at 30 and 120 min after insulin. Genes and protein expression of key molecules involved in the insulin signaling cascade (insulin receptor, insulin receptor substrate-1, p85, phosphatidylinositol 3-kinase, Akt, and AS160) were sequenced, and insulin-mediated changes were analyzed.RESULTS-Overall, baboons show a wide range of insulin sensitivity (6.2 Ϯ 4.8 mg ⅐ kg Ϫ1 ⅐ min Ϫ1 ), and there is a strong inverse correlation between indexes of adiposity and insulin sensitivity (r ϭ Ϫ0.946, P Ͻ 0.001 for % body fat; r ϭ Ϫ0.72, P Ͻ 0.001 for waist circumference). The genes and protein sequences analyzed were found to have ϳ98% identity to those of man. Insulin-mediated changes in key signaling molecules were impaired both in muscle and adipose tissue in obese insulinresistant compared with lean insulin-sensitive baboons. CONCLUSIONS-The obese baboon is a pertinent nonhuman primate model to examine the underlying cellular/molecular mechanisms responsible for insulin resistance and eventual development of type 2 diabetes. Diabetes 57:899-908, 2008 I nsulin resistance is characterized by impaired response of target organs (e.g., skeletal muscle, liver, adipose tissue, and heart) to the physiological effects of insulin and results in impaired glucose metabolism. Insulin resistance is a characteristic feature of many common metabolic disorders, including obesity, type 2 diabetes, hypertension, and dyslipidemia, and of the normal aging process, which collectively constitute risk factors for the development of atherosclerotic cardiovascular disease (1-3).Nonhuman primates occupy a unique place in biomedical and evolutionary research by virtue of their close genetic and physiological similarity to humans and represent a valuable model that has great relevance to the study of human disease. Old World monkeys, which recently (ϳ25 millions years ago in evolutionary terms) diverged from the Hominoidea, have been most extensively studied (4,5). This taxonomic group includes vervet monkeys (Chlorocebus aethiops), rhesus macaques (Macaca mulatta), cynomolgus monkeys (Macaca fascicularis), and baboons (Papio hamadryas) (6). Despite the relevance of primate study to human disease research, there has been a shortage of primates available for biomedical research (7). Baboons and humans share great genetic similarity, with ϳ96% homology evident at the DNA level (8). The sequences of specific genes and the arrangements of genetic loci on chromosomes reflect the close evolutionary relationship between these two species (9). Not surprisingly, nonhuman primates develop many diseases similar to those in man, and they have been used as a model for osteoporos...

Oral nutritional supplementation during HD improves NS. The addition of RE during HD does not seem to augment the acute anabolic effects of intradialytic ONS on NS.

Fatty acids (FAs) have been related to changes in glucose and lipid metabolism. In this article, the authors assess the association between intake of specific FAs and components of the metabolic syndrome (MS) in adult Eskimos. A total of 691 Inupiat Eskimos (325 men and 366 women), aged 34 to 75 years, were examined as part of the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. The investigation included a physical examination, blood pressure measurements, blood sampling under fasting conditions, 2-hour oral glucose tolerance test, and a personal interview including a validated food frequency questionnaire. Components of MS were defined according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel criteria. Consumption of individual FAs showed associations with MS components. Long-chain omega-3 FAs, from fish and sea mammals, were associated with lower blood pressure, serum triglycerides, and 2-hour glucose and higher high-density lipoprotein cholesterol, fasting insulin, and homeostasis model assessment. Saturated fat consumption was associated with higher triglyceride levels and blood pressure. Trans-FA consumption was associated with higher blood pressure. Consumption of long-chain omega-3 FAs from marine sources may improve certain MS components, and thus may reduce risk for cardiovascular disease. High consumption of saturated FAs and trans-FAs may have an adverse effect on MS.