NT-proBNP levels, atherosclerosis and vascular function in asymptomatic type 2 diabetic patients with microalbuminuria: peripheral reactive hyperaemia index but not NT-proBNP is an independent predictor of coronary atherosclerosis

Abstract

Intensive multifactorial treatment aimed at cardiovascular (CV) risk factor reduction in type 2 diabetic patients with microalbuminuria can diminish fatal and non-fatal CV. Plasma N-terminal (NT)-proBNP predicts CV mortality in diabetic patients but the utility of P-NT-proBNP in screening for atherosclerosis is unclear. We examined the interrelationship between P-NT-proBNP, presence of atherosclerosis and/or vascular dysfunction in the coronary, carotid and peripheral arteries in asymptomatic type 2 diabetic patients with microalbuminuria that received intensive multifactorial treatment.

Methods and Results

P-NT-proBNP was measured in 200 asymptomatic type 2 patients without known cardiac disease that received intensive multifactorial treatment for CV risk reduction. Patients were examined for coronary, carotid and peripheral atherosclerosis, as defined by coronary calcium score ≥400, carotid intima-media thickness (CIMT) > 0.90 mm, ankle-brachial index < 0.90, and/or toe-brachial index < 0.64, respectively. Carotid artery compliance was also determined and the reactive hyperaemia index (RHI) measured by peripheral artery tonometry was used as a surrogate for endothelial function.

P-NT-proBNP was associated with atherosclerosis in the unadjusted analysis, but not after adjustment for conventional risk factors. P-NT-proBNP was not associated with vascular dysfunction. The prevalence of atherosclerosis in the coronary, carotid and peripheral arteries was 35%, 10% and 21% of all patients, respectively. In total 49% had atherosclerosis in one territory and 15.6% and 1.0% in two and three territories. Low RHI was an independent predictor of coronary atherosclerosis (odds ratio [CI], 2.60 [1.15-5.88] and systolic blood pressure was the only independent determinant of CIMT (0.02 mm increase in CIMT per 10 mmHg increase in systolic blood pressure [p = 0.003]).

Conclusions

Half of asymptomatic patients with type 2 diabetes mellitus and microalbuminuria had significant atherosclerosis in at least one vascular territory despite receiving intensive multifactorial treatment for CV risk reduction. Coronary atherosclerosis was most prevalent, whereas carotid disease was more rarely observed. RHI but not plasma NT-proBNP was predictive of coronary atherosclerosis.