Brachial artery reactivity in asymptomatic patients with type 2 diabetes mellitus and microalbuminuria (from the Detection of Ischemia in Asymptomatic Diabetics-brachial artery reactivity study).
Microalbuminuria is a novel atherosclerotic risk factor in patients with type 2 diabetes mellitus (DM) and predicts future cardiovascular events. Endothelial dysfunction and systemic inflammation have been proposed as common links between microalbuminuria and cardiovascular disease. However, no study has assessed the relation between microalbuminuria and vascular dysfunction as measured by brachial artery reactivity (BAR) in DM. We evaluated 143 patients (85 men; mean age 60.0 +/- 6.7 years) with DM (mean duration 8.2 +/- 7.4 years) enrolled in the Detection of Ischemia in Asymptomatic Diabetics study. Subjects were categorized as those with microalbuminuria (ratio of urinary albumin to creatinine 30 to 299 microg/mg creatinine, n = 28) and those with normoalbuminuria (ratio of urinary albumin to creatinine 0 to 29.9 microg/mg creatinine, n = 115). High-resolution ultrasound BAR testing was used to measure endothelium-dependent and endothelium-independent vasodilations. C-reactive protein was measured as a marker of systemic inflammation. Patients with microalbuminuria and normoalbuminuria had similar baseline characteristics, with the exception that those with microalbuminuria had a longer duration of DM (p = 0.03). Endothelium-dependent vasodilation at 1 minute (p = 0.01) and endothelium-independent vasodilation at 3 minutes (p = 0.007) were significantly less in patients with microalbuminuria. In addition, 96% of patients with microalbuminuria and 76% of those with normoalbuminuria had impaired endothelium-dependent vasodilation (<8%, p = 0.01). Microalbuminuria was an independent predictor of endothelium-dependent vasodilation in the entire cohort (p = 0.045) and after excluding patients on hormone replacement therapy (p = 0.01). Levels of C-reactive protein were significantly higher in patients with microalbuminuria than in those with normoalbuminuria (p = 0.02). We conclude that in DM the presence of microalbuminuria is associated with impaired endothelium-dependent and endothelium-independent vasodilations of the brachial artery and a higher degree of systemic inflammation. In addition, microalbuminuria is an independent predictor of endothelial dysfunction in asymptomatic patients with DM, especially in the absence of hormone replacement therapy.
Cardiology Division, Henry Low Heart Center, Hartford Hospital, and University of Connecticut School of Medicine, Farmington, USA.
Georgios I
GI
Papaioannou
Richard L
RL
Seip
Neil J
NJ
Grey
Deborah
D
Katten
Amy
A
Taylor
Silvio E
SE
Inzucchi
Lawrence H
LH
Young
Deborah A
DA
Chyun
Janice A
JA
Davey
Frans J Th
FJ
Wackers
Ami E
AE
Iskandrian
Robert E
RE
Ratner
Evelyn C
EC
Robinson
Stella
S
Carolan
Samuel
S
Engel
Gary V
GV
Heller
D000367:Age Factors; D000368:Aged; D000419:Albuminuria / Q000150:complications / Q000175:diagnosis*; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D002097:C-Reactive Protein / Q000032:analysis*; D003324:Coronary Artery Disease / Q000209:etiology / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000175:diagnosis*; D003925:Diabetic Angiopathies / Q000150:complications / Q000000981:diagnostic imaging*; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D018608:Ultrasonography, Doppler; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
D002097:C-Reactive Protein