Plasma NT-proBNP and white matter hyperintensities in type 2 diabetic patients

Abstract

Elevated plasma N-terminal (NT)-proBNP from the heart as well as white matter hyperintensities (WMH) in the brain predict cardiovascular (CV) mortality in the general population. The cause of poor prognosis associated with elevated P-NT-proBNP is not known but WMH precede strokes in high risk populations. We assessed the association between P-NT-proBNP and WMH or brain atrophy measured with magnetic resonance imaging (MRI) in type 2 diabetic patients, and age-matched controls.

Methods and results: We measured P-NT-proBNP(ng/l) in 20 diabetic patients without prior stroke but with(n=10) or without(n=10) asymptomatic coronary artery disease(CAD) in order to include patients with a wide-ranging CV risk profile. All patients and 26 controls had a 3D MRI and brain volumes(ml) with WMH and brain parenchymal fraction(BPF), an indicator of brain atrophy, were determined.P-NT-proBNP was associated with WMH in linear regression analysis adjusted for CV risk factors(r=0.94, p=0.001) and with BPF in univariate analysis(r=0.57, p=0.009). Patients divided into groups of increased P-NT-proBNP levels were paralleled with increased WMH volumes(geometric mean[SD];(2.86[5.11] ml and 0.76[2.49] ml compared to patients with low P-NT-proBNP 0.20[2.28] ml, p=0.003)) and also when adjusted for age, sex and presence of CAD(p=0.017). The association was strengthened by CV risk factors and we did not find a common heart or brain specific driver of both P-NT-proBNP and WMH. Patients and particular patients with CAD had higher WMH, however no longer after adjustment for age and sex.

Conclusion: P-NT-proBNP was associated with WMH in type 2 diabetic patients, suggesting a linkage between heart and brain disease.

Figure 1

Univariate linear regression analysis with the logarithm of plasma NT-proBNP (ng/l) in relation to the logarithm of white matter hyperintensities in 20 patients with type 2 diabetes.

Figure 2

A scatter plot correlation, showing white matter hyperintensities in 20 patients with type 2 diabetes and with low, intermediate and high plasma NT-proBNP levels (tertile values), respectively, (horizontal bar is geometric mean among the groups, p = 0.003).