title: Association between insulin resistance and endothelial dysfunction in type 2 diabetes and the effects of pioglitazone.
abstract: Endothelial dysfunction is regarded as an early stage of atherosclerosis, and plays a role in the development of atherosclerotic diseases. Insulin resistance is related to the atherosclerotic process. In this study, we examined the association between endothelial function and insulin resistance in 48 subjects with type 2 diabetes. In addition, the effects of pioglitazone treatment on endothelial function and insulin resistance were investigated in a subgroup of subjects. Endothelial function of the brachial artery was non-invasively assessed using ultrasound technique. We measured flow-mediated endothelium-dependent vasodilation (FMD) and glyceryl trinitrate-induced endothelium-independent vasodilation (GTN). Insulin sensitivity was measured by the steady-state plasma glucose (SSPG) method. High SSPG levels indicate insulin resistance. There was a significant inverse correlation (r=-0.462, p<0.001) between SSPG and FMD. Systolic blood pressure was inversely correlated with FMD (r=-0.360, p<0.013). By multiple regression analysis, insulin resistance was the sole predictor of FMD. The effects of chronic treatment with pioglitazone were assessed in 10 subjects with type 2 diabetes. The increase in FMD significantly correlated with the decrease in SSPG. There is a significant association between vascular endothelial dysfunction and insulin resistance in type 2 diabetes. This result was supported by the effects of the insulin sensitizer, pioglitazone.
authors.affiliation: Department of Diabetes and Metabolic Disease, Osaka General Medical Center, 3-1-56 Mandai-higashi, Sumiyoshi-ku, Osaka 558-8558, Japan. masuzuki@gh.pref.osaka.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Itaru
authors.initials: I
authors.lastname: Takamisawa
authors.forename: Yasunao
authors.initials: Y
authors.lastname: Yoshimasa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Harano
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D005996:Nitroglycerin / Q000031:analogs & derivatives / Q000494:pharmacology; D000077205:Pioglitazone; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000627:therapeutic use*; D014664:Vasodilation / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D045162:Thiazolidinediones; C014509:dinitroglycerol; D005996:Nitroglycerin; D000077205:Pioglitazone