title: The role of acetic acid on glucose uptake and blood flow rates in the skeletal muscle in humans with impaired glucose tolerance.
abstract: OBJECTIVE
  Previous studies support the glucose-lowering effect of vinegar. However, the effect of vinegar on muscle glucose metabolism and endothelial function has not been studied in humans. This open, randomized, crossover, placebo-controlled study aims to investigate the effects of vinegar on muscle glucose metabolism, endothelial function and circulating lipid levels in subjects with impaired glucose tolerance (IGT) using the arteriovenous difference technique.
  
  
  METHODS
  Eight subjects with IGT (4 males, age 46±10 years, body mass index 30±5) were randomised to consume 0.50 mmol vinegar (6% acetic acid) or placebo before a mixed meal. Plasma samples were taken for 300 min from the radial artery and the forearm vein for measurements of glucose, insulin, triglycerides, non-esterified fatty acids (NEFAs) and glycerol. Muscle blood flow was measured with strain gauge plethysmography. Glucose flux was calculated as the arteriovenous difference of glucose multiplied by the blood flow rates.
  
  
  RESULTS
  Vinegar compared with placebo: (1) decreased arterial plasma insulin (Poverall<0.001; P75 min=0.014, β=-42), (2) increased forearm blood flow (Poverall<0.001; P240 min=0.011, β=1.53; P300 min=0.023, β=1.37), (3) increased muscle glucose uptake (Poverall<0.001; P60 min=0.029, β=2.78) and (4) decreased arterial plasma triglycerides (Poverall=0.005; P240 min<0.001, β=-344; P300 min<0.001, β=-373), without changing NEFA and glycerol.
  
  
  CONCLUSIONS
  In individuals with IGT, vinegar ingestion before a mixed meal results in an enhancement of muscle blood flow, an improvement of glucose uptake by the forearm muscle and a reduction of postprandial hyperinsulinaemia and hypertriglyceridaemia. From this point of view, vinegar may be considered beneficial for improving insulin resistance and metabolic abnormalities in the atherogenic prediabetic state.
authors.affiliation: Hellenic National Center for Research, Prevention and Treatment of Diabetes Mellitus and its Complications (H.N.D.C.), Athens, Greece.
authors.forename: P
authors.initials: P
authors.lastname: Mitrou
authors.affiliation: Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Petsiou
authors.affiliation: Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Papakonstantinou
authors.affiliation: Hellenic National Center for Research, Prevention and Treatment of Diabetes Mellitus and its Complications (H.N.D.C.), Athens, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Maratou
authors.affiliation: Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: V
authors.initials: V
authors.lastname: Lambadiari
authors.affiliation: Department of Water Resources and Environmental Engineering, School of Civil Engineering, NTUA, Athens, Greece.
authors.forename: P
authors.initials: P
authors.lastname: Dimitriadis
authors.affiliation: Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: F
authors.initials: F
authors.lastname: Spanoudi
authors.affiliation: 1] Hellenic National Center for Research, Prevention and Treatment of Diabetes Mellitus and its Complications (H.N.D.C.), Athens, Greece [2] Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: S A
authors.initials: SA
authors.lastname: Raptis
authors.affiliation: Second Department of Internal Medicine and Research Institute, Athens University Medical School, Attikon University Hospital, Haidari, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Dimitriadis
mesh_terms: D065567:Absorption, Physiological; D019342:Acetic Acid / Q000627:therapeutic use*; D000328:Adult; D001628:Beverages; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D015992:Body Mass Index; D018592:Cross-Over Studies; D004730:Endothelium, Vascular / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D005542:Forearm; D006801:Humans; D006946:Hyperinsulinism / Q000209:etiology / Q000517:prevention & control; D015228:Hypertriglyceridemia / Q000209:etiology / Q000517:prevention & control; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism*; D050177:Overweight / Q000150:complications; D010991:Plethysmography; D019518:Postprandial Period; D011236:Prediabetic State / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology; D012039:Regional Blood Flow
chemical_list: D001786:Blood Glucose; D019342:Acetic Acid