Effect of Insulin Glulisine on Microvascular Blood Flow and Endothelial Function in the Postprandial State

Abstract

OBJECTIVE—To investigate the effect of insulin glulisine on postprandial microvascular blood flow in type 2 diabetes. RESEARCH DESIGN AND METHODS—A total of 15 patients with type 2 diabetes received insulin glulisine or human insulin before a liquid meal test. Thereafter, skin microvascular blood flow was measured by laser Doppler fluxmetry and blood samples were taken for measurement of plasma levels of glucose, insulin, intact proinsulin, asymmetric dimethylarginine, nitrotyrosine, interleukin-18, matrix metalloproteinase-9, oxidized LDL, and free fatty acids. RESULTS—Insulin glulisine injections resulted in higher postprandial insulin levels (means ± SEM area under the curve [AUC]0–120 51.0 ± 6.8 vs. 38.2 ± 5.4 mU/l; P = 0.004), while plasma glucose (AUC0–240 158 ± 9 vs. 180 ± 9 mg/dl; P < 0.05) and intact proinsulin (AUC0–240 26.2 ± 3.5 vs. 31.2 ± 4.3 pmol/l; P = 0.002) were lower. Microvascular blood flow increased after insulin glulisine injection (27.9 ± 3.1 to 51.7 ± 9.9 arbitrary units [AU]; P < 0.05), while only a minor increase was found during human insulin (27.9 ± 3.1 to 34.4 ± 7.8 AU; not significant). Asymmetric dimethylarginine and nitrotyrosine levels were reduced after insulin glulisine (P < 0.05). CONCLUSIONS—Insulin glulisine is superior to human insulin in restoring postprandial metabolic and microvascular physiology.