Influence of glucose control and improvement of insulin resistance on microvascular blood flow and endothelial function in patients with diabetes mellitus type 2.
OBJECTIVE
The study was performed to investigate the effect of improving metabolic control with pioglitazone in comparison to glimepiride on microvascular function in patients with diabetes mellitus type 2.


METHODS
A total of 179 patients were recruited and randomly assigned to one treatment group. Metabolic control (HbA1c), insulin resistance (HOMA index), and microvascular function (laser Doppler fluxmetry) were observed at baseline and after 3 and 6 months.


RESULTS
HbA1c improved in both treatment arms (pioglitazone: 7.52 +/- 0.85% to 6.71 +/- 0.89%, p < .0001; glimepiride: 7.44 +/- 0.89% to 6.83 +/- 0.85%, p < .0001). Insulin-resistance decreased significantly in the pioglitazone group (6.15 +/- 4.05 to 3.85 +/- 1.92, p < .0001) and remained unchanged in the glimepiride group. The microvascular response to heat significantly improved in both treatment groups (pioglitazone 48.5 [15.2; 91.8] to 88.8 [57.6; 124.1] arbitrary units [AU], p < .0001; glimepiride 53.7 [14.1; 91.9] to 87.9 [52.9, 131.0] AU, p < .0001, median [lower and upper quartile]). Endothelial function as measured with the acetylcholine response improved in the pioglitazone group (38.5 [22.2; 68.0] to 60.2 [36.9; 82.8], p = .0427) and remained unchanged in the glimepiride group.


CONCLUSIONS
Improving metabolic control has beneficial effects in microvascular function in type 2 diabetic patients. Treatment of type 2 diabetic patients with pioglitazone exerts additional effects on endothelial function beyond metabolic control.
Forst
Thomas
T
Institute for Clinical Research and Development, Mainz, Germany. thomasf@ikfe.de
Lübben
Georg
G
Hohberg
Clothilde
C
Kann
Peter
P
Sachara
Christian
C
Gottschall
Volker
V
Friedrich
Christiane
C
Rosskopf
Reiner
R
Pfützner
Andreas
A
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007333:Insulin Resistance; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000503:physiopathology; D008875:Middle Aged; D000077205:Pioglitazone; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D045162:Thiazolidinediones / Q000627:therapeutic use*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; C057619:glimepiride; D000077205:Pioglitazone