Diabetes & metabolism
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Diabetes & metabolism · Dec 2009
ReviewWhat can bariatric surgery teach us about the pathophysiology of type 2 diabetes?
Bariatric surgery is indicated in cases of severe obesity. However, malabsorption-based techniques (gastric bypass and biliopancreatic diversion, both of which exclude the duodenum and jejunum from the alimentary circuit), but not restrictive techniques, can abolish type 2 diabetes within days of surgery, even before any significant weight loss has occurred. This means that calorie restriction alone cannot entirely account for this effect. ⋯ In the medium term and in parallel with weight loss, a decrease in fatty tissue inflammation (which is also seen with restrictive techniques) may also be involved in metabolic improvement. Other mechanisms specific to malabsorption-based techniques (due to the required exclusion of part of the intestine), such as changes in the activity of digestive vagal afferents, changes in intestinal flora and stimulation of intestinal neoglucogenesis, also need to be studied in greater detail. The intestine is, thus, a key organ in the regulation of glycaemic equilibrium and may even be involved in the pathophysiology of type 2 diabetes.
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Diabetes & metabolism · Feb 2009
ReviewStrategies for the diagnosis and treatment of neuropathic pain secondary to diabetic peripheral sensory polyneuropathy.
This article proposes a strategy for the diagnosis and treatment of neuropathic pain due to diabetic peripheral sensory neuropathy, based on 15 years of experience in French pain-management centres and on the available literature. In the diabetic patient with chronic pain in the lower limbs, the first step in the diagnostic process is to identify the neuropathic origin of the pain. ⋯ In the third step, adequate and well-tolerated treatment directed towards a variety of painful symptoms is selected, taking into account other co-morbidities such as anxiety and depression. This report reports on the clinical aspects of neuropathic pain exhibited by patients with diabetic sensory polyneuropathy, and the key factors in their diagnosis and treatment, based on the results of meta-analyses and on a recent expert consensus.
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Diabetes & metabolism · Dec 2008
ReviewThe incretins: from the concept to their use in the treatment of type 2 diabetes. Part A: incretins: concept and physiological functions.
This paper briefly reviews the concept of incretins and describes the biological effects of the two incretins identified so far: the glucose-dependent insulinotropic polypeptide (GIP); and the glucagon-like peptide-1 (GLP-1). GIP is released by the Kcells of the duodenum, while GLP-1 is released by the Lcells of the distal ileum, in response to nutrient absorption. GIP and GLP-1 stimulate insulin biosynthesis and insulin secretion in a glucose-dependent manner. ⋯ By inhibiting glucagon secretion and delaying gastric-emptying, GLP-1 plays an important role in glucose homoeostasis and, by inhibiting food intake, prevents the increase in body weight. As the metabolic effects of GIP are blunted in type 2 diabetes, this peptide cannot be used as an efficient therapy for diabetes. In contrast, GLP-1 effects are preserved at high concentrations in type 2 diabetes, making this peptide of great interest for the treatment of diabetes, a topic that will be discussed in the second part of this review.
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Diabetes & metabolism · Sep 2008
ReviewImpact of visceral adipose tissue on liver metabolism. Part I: heterogeneity of adipose tissue and functional properties of visceral adipose tissue.
Excess visceral adipose tissue is associated with anomalies of blood glucose homoeostasis, elevation of plasma triglycerides and low high-density lipoprotein cholesterol that contribute to the later appearance of type 2 diabetes and cardiovascular syndromes. Visceral adipose tissue releases a large amount of free fatty acids and hormones/cytokines in the portal vein that are delivered to the liver, and interact with hepatocytes and various immune cells in the liver. The functional characteristics of visceral adipose tissue will be compared with subcutaneous adipose tissue to clarify the major mechanisms affecting free fatty acid metabolism and cytokine production.
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Diabetes & metabolism · Feb 2008
ReviewAdipokines: the missing link between insulin resistance and obesity.
White adipose tissue was believed to be just an energy-storage organ, but it is now recognized to be an active participant in energy homoeostasis and physiological functions such as immunity and inflammation. Macrophages are components of adipose tissue and actively participate in its activities. Adipose tissue is known to express and secrete a variety of products known as 'adipokines', including leptin, adiponectin, resistin and visfatin, as well as cytokines and chemokines such as tumor necrosis factor-alpha, interleukin-6 and monocyte chemoattractant protein-1. The release of adipokines by either adipocytes or adipose tissue-infiltrated macrophages leads to a chronic subinflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes, and the increased risk of cardiovascular disease associated with obesity.