Diabetes & metabolism
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Diabetes & metabolism · Jun 2005
ReviewIs capillary ketone determination useful in clinical practice? In which circumstances?
A new method is now available to measure capillary levels of 3-hydroxybutyrate (3HB), one of the three ketone bodies. It is a quantitative and enzymatic test that uses the same equipment as for home capillary blood glucose determination but with specific strips. In comparison to urine ketone test, there is no false negative or false positive results, it is highly correlate to standard automate assays and patients find it more acceptable. ⋯ For other situations such as diabetic pregnancy or type 2 diabetes, more data are needed to determine if capillary measurement of 3HB is really useful. This new test is easier and less unpleasant than doing urinary test but it is still far more expensive. Further clinical studies are needed to define whether self 3HB monitoring should substitute urinary test in outpatient care.
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It is now recognized that the white adipose tIssue (WAT) produces a variety of bioactive peptIdes, collectively termed "adipokines". Alteration of WAT mass in obesity or lipoatrophy, affects the production of most adipose secreted factors. Since both conditions are associated with multiple metabolic disorders and increased risk of cardiovascular diseases, the Idea has emerged that WAT could be instrumental in these complications, by virtue of its secreted factors. ⋯ In lipoatrophic mice, where leptin and adiponectin circulating levels are low, administration of the two adipokines synergistically reverses insulin resistance. Leptin and adiponectin also have distinct properties: leptin, as a long-term integrative signal of energy store and adiponectin, as a potent anti-atherogenic agent. The thiazolIdinedione anti-diabetic drugs increase endogenous adiponectin production in rodents and humans, supporting the Idea that the development of new drugs targeting adipokines might represent a promising therapeutic approach to protect obese patients from insulin resistance and atherosclerosis.
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Diabetes & metabolism · Sep 2003
ReviewMitochondrial metabolism and type-2 diabetes: a specific target of metformin.
Several links relate mitochondrial metabolism and type 2 diabetes or chronic hyperglycaemia. Among them, ATP synthesis by oxidative phosphorylation and cellular energy metabolism (ATP/ADP ratio), redox status and reactive oxygen species (ROS) production, membrane potential and substrate transport across the mitochondrial membrane are involved at various steps of the very complex network of glucose metabolism. Recently, the following findings (1) mitochondrial ROS production is central in the signalling pathway of harmful effects of hyperglycaemia, (2) AMPK activation is a major regulator of both glucose and lipid metabolism connected with cellular energy status, (3) hyperglycaemia by inhibiting glucose-6-phosphate dehydrogenase (G6PDH) by a cAMP mechanism plays a crucial role in NADPH/NADP ratio and thus in the pro-oxidant/anti-oxidant cellular status, have deeply changed our view of diabetes and related complications. ⋯ However, recent important findings may explain its unique efficacy in the treatment of hyperglycaemia- or insulin-resistance related complications. Metformin is a mild inhibitor of respiratory chain complex 1; it activates AMPK in several models, apparently independently of changes in the AMP-to-ATP ratio; it activates G6PDH in a model of high-fat related insulin resistance; and it has antioxidant properties by a mechanism (s), which is (are) not completely elucidated as yet. Although it is clear that metformin has non-mitochondrial effects, since it affects erythrocyte metabolism, the mitochondrial effects of metformin are probably crucial in explaining the various properties of this drug.
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Diabetes & metabolism · Sep 2003
Editorial ReviewIs metformin more than an oral hypoglycaemic agent?
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Diabetes & metabolism · Dec 2002
Review Comparative StudyNew antiobesity agents in type 2 diabetes: overview of clinical trials with sibutramine and orlistat.
Besides genetic predisposition, obesity is the most important risk factor for the development of type 2 diabetes mellitus. Even modest weight reduction can improve blood glucose control in overweight subjects. After failure of lifestyle modifications, antiobesity drugs such as orlistat, a potent and selective inhibitor of gastric and pancreatic lipases that reduces lipid intestinal absorption, or sibutramine, a noradrenaline and 5-hydroxytryptamine reuptake inhibitor that regulates food intake, may be considered to favour weight loss and/or weight maintenance. ⋯ In addition, vascular risk factors associated to insulin resistance were also reduced after weight loss. These antiobesity agents may also contribute to delay or prevent the progression from impaired glucose tolerance to overt type 2 diabetes in at risk obese individuals ("Xenical in the prevention of diabetes in obese subjects" trial). Large long-term prospective studies, such as the "Sibutramine cardiovascular and diabetes outcome study" should better determine the place of pharmacological anti-obesity strategy in the overall management of obese patients with impaired glucose tolerance or type 2 diabetes.