Metabolism-clinical and Experimental 

About: Metabolism-clinical and Experimental is an academic journal published by Elsevier BV. The journal publishes majorly in the area(s): Insulin & Diabetes mellitus. It has an ISSN identifier of 0026-0495. Over the lifetime, 13555 publications have been published receiving 538282 citations. The journal is also known as: Metabolism.

The multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD)

Abstract: Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. Despite its high prevalence, only a small minority of affected patients develops inflammation and subsequently fibrosis and chronic liver disease, while most of them only exhibit simple steatosis. In this context, the full understanding of the mechanisms underlying the development of NAFLD and non-alcoholic steatohepatitis (NASH) is of extreme importance; despite advances in this field, knowledge on the pathogenesis of NAFLD is still incomplete. The 'two-hit' hypothesis is now obsolete, as it is inadequate to explain the several molecular and metabolic changes that take place in NAFLD. The "multiple hit" hypothesis considers multiple insults acting together on genetically predisposed subjects to induce NAFLD and provides a more accurate explanation of NAFLD pathogenesis. Such hits include insulin resistance, hormones secreted from the adipose tissue, nutritional factors, gut microbiota and genetic and epigenetic factors. In this article, we review the factors that form this hypothesis.

The theoretical bases of indirect calorimetry: a review

Abstract: Indirect calorimetry is the method by which the type and rate of substrate utilization, and energy metabolism are estimated in vivo starting from gas exchange measurements. This technique provides unique information, is noninvasive, and can be advantageously combined with other experimental methods to investigate numerous aspects of nutrient assimilation, thermogenesis, the energetics of physical exercise, and the pathogenesis of metabolic diseases. Since its use as a research tool in metabolism is growing, the theoretical bases of indirect calorimetry are here reviewed in a detailed and orderly fashion. Special cases, such as the occurrence of net lipid synthesis or gluconeogenesis, are formally considered with derivation of explicit stoichiometric equations. The limitations of indirect calorimetry, both theoretical and technical, are discussed in the context of circumstances of clinical interest in metabolism.

Pathogenesis of atherosclerosis.

Abstract: There is abundant evidence that changes in diet and various types of vessel wall injury can independently induce the growth of arterial lesions in experimental animals. These lesions closely resemble those found in humans with atherosclerosis. Whether endothelial injury or accumulation of lipoprotein in the arterial intima is the initial event, the progression of the disease is characterized by changes in the neointima that favor the deposition of lipid. The metabolism of proteoglycans may be especially important in this process; this is relevant to diabetes because changes in proteoglycan metabolism are associated with this disease. Insulin and growth hormone may favor the proliferation of smooth muscle cells in the arteries of diabetic patients. Many agents, which are potentially injurious to the endothelium, accentuate the response of the vessel wall to injury. Modifications of the thrombotic process, such as increased production of thromboxane by platelets, decreased production of prostacyclin by the endothelium, and increased production of von Willebrand factor further enhance the thrombotic process and may be important in the initiation and subsequent progression of atherosclerosis in diabetics. Alterations in lipoprotein metabolism may also facilitate the development of endothelial injury.

The epidemiology of obesity

Abstract: Obesity is a complex multifactorial disease. The worldwide prevalence of overweight and obesity has doubled since 1980 to an extent that nearly a third of the world's population is now classified as overweight or obese. Obesity rates have increased in all ages and both sexes irrespective of geographical locality, ethnicity or socioeconomic status, although the prevalence of obesity is generally greater in older persons and women. This trend was similar across regions and countries, although absolute prevalence rates of overweight and obesity varied widely. For some developed countries, the prevalence rates of obesity seem to have levelled off during the past few years. Body mass index (BMI) is typically used to define overweight and obesity in epidemiological studies. However, BMI has low sensitivity and there is a large inter-individual variability in the percent body fat for any given BMI value, partly attributed to age, sex, and ethnicity. For instance, Asians have greater percent body fat than Caucasians for the same BMI. Greater cardiometabolic risk has also been associated with the localization of excess fat in the visceral adipose tissue and ectopic depots (such as muscle and liver), as well as in cases of increased fat to lean mass ratio (e.g. metabolically-obese normal-weight). These data suggest that obesity may be far more common and requires more urgent attention than what large epidemiological studies suggest. Simply relying on BMI to assess its prevalence could hinder future interventions aimed at obesity prevention and control.

Contribution of intra-abdominal fat accumulation to the impairment of glucose and lipid metabolism in human obesity

Abstract: The casual relationship between intraabdominal visceral fat accumulation and metabolic disorders was analyzed in 46 obese subjects (15 males, 31 females) having 34.1 +/- 5.5 of body mass index (BMI). The distribution of fat was determined by our CT scanning technique (Int J Obesity 7:437, 1983). The total cross-cut area, subcutaneous fat area, and intra-abdominal fat area was measured at the umbilical level. The fasting plasma glucose level, area under the plasma glucose concentration curve after oral glucose loading (plasma glucose area), fasting serum triglyceride level, and serum total cholesterol level were all significantly higher or otherwise greater in the group with intraabdominal visceral fat to subcutaneous fat ratio (V/S ratio) of not less than 0.4 than in the group with a lower V/S ratio, when either all or sex-matched obese subjects were examined, though BMI or the duration of obesity was not different between the two groups. The V/S ratio was significantly correlated with the level of plasma glucose area (r = 0.45, P less than .001) under the curve of 75 g oral glucose tolerance test and also with the serum triglyceride (r = 0.65, P less than .001) and total cholesterol levels (r = 0.61, P less than .001). These relationships were also observed when examined in each sex separately and found to be significant after adjustment for BMI and age by multiple regression analyses.(ABSTRACT TRUNCATED AT 250 WORDS)