Effects of carvedilol versus metoprolol on endothelial function and oxidative stress in patients with type 2 diabetes mellitus.
BACKGROUND
Data suggest that carvedilol possesses antioxidant properties that might provide vascular protection. We sought to compare the effects of carvedilol and metoprolol tartrate on endothelial function and oxidative stress in a head-to-head trial.


METHODS
Thirty-four patients with type 2 diabetes mellitus (T2DM) and hypertension were randomized to receive either carvedilol (n = 16) or metoprolol (n = 18) in addition to their current antihypertensive medications for 5 months. The following variables were measured pre- and posttreatment: blood pressure, fasting glucose and insulin, insulin resistance by homeostasis-model assessment, hemoglobin A1c, lipids, C-reactive protein (CRP), 8-isoprostane, asymmetric dimethylarginine, oxidized LDL cholesterol, ultrasound assessment of brachial-artery flow-mediated dilation (FMD), nitroglycerin-induced endothelium-independent dilation (EID), brachial and carotid artery distension, distensibility and compliance, and carotid artery intima-media thickness (cIMT).


RESULTS
Both carvedilol and metoprolol treatment resulted in significant and similar decreases in systolic (P < .05) and diastolic (P < .0001) blood pressure. Compared with metoprolol, carvedilol significantly improved FMD (P < .001). No differences between groups were noted for any of the glycemic or lipid variables except for HDL cholesterol, which significantly decreased (P < .05) in the metoprolol group compared with the carvedilol group. No differences were observed between groups for CRP, the markers of oxidative stress, EID, arterial stiffness, or cIMT.


CONCLUSIONS
Compared with metoprolol, carvedilol significantly improves endothelial function in patients with T2DM. Changes in glycemic control and oxidative stress do not seem to explain the observed improvements in FMD, which suggests that other mechanisms may be involved.
Bank
Alan J
AJ
Department of Research, St. Paul Heart Clinic, St. Paul, Minnesota, USA. abank@stphc.com
Kelly
Aaron S
AS
Thelen
Andrea M
AM
Kaiser
Daniel R
DR
Gonzalez-Campoy
J Michael
JM
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002227:Carbazoles / Q000627:therapeutic use*; D000077261:Carvedilol; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D011412:Propanolamines / Q000627:therapeutic use*
D000959:Antihypertensive Agents; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol