The Effect of Elevated Blood Pressure on Rich-Club Organization: A Multicenter MR Diffusion Tensor Imaging Study From Prehypertension to Hypertension.

Abstract

Background: Hypertension-induced alterations in brain network topology remain poorly understood, and diffusion tensor imaging (DTI) offers a promising approach for detecting early structural changes.

Hypothesis: Rich-club organization undergoes progressive disruption from prehypertension to hypertension, and these alterations may serve as potential imaging biomarkers for hypertension.

Study type: Cross-sectional.

Subjects: Five hundred thirteen participants (150 healthy controls, 175 prehypertensive individuals, and 188 hypertensive patients).

Sequence: DTI with an echo planar imaging sequence at 3.0 T.

Assessment: Whole-brain structural networks were constructed using deterministic fiber tracking. Modularity, rich-club organization (rich-club, feeder and local connections), small-world property, global efficiency, local efficiency, clustering coefficient, and nodal efficiency were quantified using graph-theoretical analysis. Network-based statistics (NBS) were applied to identify significant group differences in white matter connectivity.

Statistical tests: Analysis of variance for group comparisons, with post hoc least significant difference t-testing. Logistic regression assessed the predictive power of network features, while Pearson correlation evaluated relationships between blood pressure and network disruptions. Area under the receiver operating characteristic (ROC) curve (AUC) was used to assess diagnostic performance. A significance threshold of p < 0.05 was applied.

Results: Prehypertensive individuals exhibited significant early reductions in feeder connections, whereas hypertensive patients demonstrated widespread significant deterioration in rich-club connections. A statistically significant compensatory increase in local connection strength was observed in prehypertension but declined in hypertension. Logistic regression confirmed that rich-club connection strength and density effectively differentiated hypertensive individuals, with ROC analysis showing good discriminatory power (AUC: 0.803 and 0.816, respectively).

Data conclusion: This study showed progressive disruption of rich-club organization in prehypertension and hypertension. This disruption has the potential to be an early neuroimaging biomarker for identifying individuals at risk of hypertension-related brain dysfunction.

Evidence level: 2.

Technical efficacy: Stage 2.