title: Effects of thiamine and benfotiamine on intracellular glucose metabolism and relevance in the prevention of diabetic complications.
abstract: Thiamine (vitamin B1) is an essential cofactor in most organisms and is required at several stages of anabolic and catabolic intermediary metabolism, such as intracellular glucose metabolism, and is also a modulator of neuronal and neuro-muscular transmission. Lack of thiamine or defects in its intracellular transport can cause a number of severe disorders. Thiamine acts as a coenzyme for transketolase (TK) and for the pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase complexes, enzymes which play a fundamental role for intracellular glucose metabolism. In particular, TK is able to shift excess fructose-6-phosphate and glycerhaldeyde-3-phosphate from glycolysis into the pentose-phosphate shunt, thus eliminating these potentially damaging metabolites from the cytosol. Diabetes might be considered a thiamine-deficient state, if not in absolute terms at least relative to the increased requirements deriving from accelerated and amplified glucose metabolism in non-insulin dependent tissues that, like the vessel wall, are prone to complications. A thiamine/TK activity deficiency has been described in diabetic patients, the correction of which by thiamine and/or its lipophilic derivative, benfotiamine, has been demonstrated in vitro to counteract the damaging effects of hyperglycaemia on vascular cells. Little is known, however, on the positive effects of thiamine/benfotiamine administration in diabetic patients, apart from the possible amelioration of neuropathic symptoms. Clinical trials on diabetic patients would be necessary to test this vitamin as a potential and inexpensive approach to the prevention and/or treatment of diabetic vascular complications.
authors.affiliation: Department of Internal Medicine, University of Turin, Corso AM Dogliotti, 14, 10126, Turin, Italy. elena.beltramo@unito.it
authors.forename: Elena
authors.initials: E
authors.lastname: Beltramo
authors.forename: Elena
authors.initials: E
authors.lastname: Berrone
authors.forename: Sonia
authors.initials: S
authors.lastname: Tarallo
authors.forename: Massimo
authors.initials: M
authors.lastname: Porta
mesh_terms: D000818:Animals; D002986:Clinical Trials as Topic; D048909:Diabetes Complications / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D005947:Glucose / Q000009:adverse effects / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D013831:Thiamine / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D005947:Glucose; D013831:Thiamine; C013835:benphothiamine