Total serum bilirubin does not affect vascular reactivity in patients with diabetes.
Bilirubin may have a major role in the prevention of cardiovascular disease based on recent data regarding its anti-oxidant properties. We determined the relationship between total serum bilirubin and vascular reactivity in a large cohort of individuals with diabetes, a disease associated with known oxidant stress. We studied 302 individuals: 52 controls, 37 with type 1 diabetes, 213 with type 2 diabetes. High-resolution ultrasound was used to measure flow-mediated dilation (FMD; endothelium-dependent) and nitroglycerin-induced dilation (NID, endothelium-independent) of the brachial artery. Laser Doppler perfusion imaging was used to measure microvascular reactivity in the forearm skin before and after iontophoresis of acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent). Bilirubin levels were higher in the type 2 diabetes group (0.71 +/- 0.34 mg/dl) compared to controls (0.56 +/- 0.26 mg/dl, p < 0.0001). A weak inverse correlation was observed between bilirubin and FMD (r = -0.125, p = 0.032) and skin endothelium-dependent vasodilation (r = -0.157, p = 0.019). In multivariate analyses, however, these correlations were not statistically significant. There is no association between bilirubin levels and vascular reactivity in the macro- and microcirculation of individuals with diabetes. Bilirubin, therefore, does not correlate with predictors of cardiovascular risk in the diabetic population.
Yeh
Susie Yim
SY
Sleep Disorders Program, Brigham and Women's Hospital, Harvard Medical School, USA.
Doupis
John
J
Rahangdale
Shilpa
S
Horr
Samuel
S
Malhotra
Atul
A
Veves
Aristidis
A
D000109:Acetylcholine / Q000008:administration & dosage; D000279:Administration, Cutaneous; D000328:Adult; D000368:Aged; D001663:Bilirubin / Q000097:blood*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005542:Forearm; D006801:Humans; D007478:Iontophoresis; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D009599:Nitroprusside / Q000008:administration & dosage; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage
D014665:Vasodilator Agents; D009599:Nitroprusside; D005996:Nitroglycerin; D000109:Acetylcholine; D001663:Bilirubin