Regional blood-brain barrier permeability is associated with cerebral microbleeds in primary aldosteronism
Z Chen, N Cao, J Fu, X Yu, L BaoAbstract
Background
Primary aldosteronism (PA), the most common endocrine cause of secondary hypertension, is associated with a higher risk of cerebral microbleeds (CMBs) compared to essential hypertension (EH). Blood-brain barrier (BBB) structural and functional impairment may be closely associated with the development of CMBs. However, the specific association between regional BBB permeability alterations and CMB formation in PA patients remains unclear. This study investigated whether BBB permeability differs among PA, EH, and healthy controls, and whether it relates to CMB burden and aldosterone levels.
Methods
A total of 90 participants were enrolled in this cross-sectional study, including 27 patients with PA (59.6 ± 14.9 years, 48.1% male), 28 patients with EH (58.6 ± 13.3 years, 78.6% male), and 35 healthy controls (53.4 ± 13.4 years, 34.3% male). All participants underwent brain magnetic resonance imaging (MRI) examinations with susceptibility-weighted imaging (SWI) sequence for evaluate CMBs presence and number, and BBB permeability was quantitatively assessed as water exchange rate (Kw) in multiple cerebral regions using diffusion-prepared psuedo-continuous Arterial spin labeling (DP-pCASL). In the PA group, Pearson correlation analysis was performed to investigate the relationship between plasma aldosterone and regional Kw values.
Results
Patients with PA exhibited a significantly higher CMB burden compared with both EH patients and healthy controls (P =0.003). No significant differences in whole-brain Kw were found among the three groups. However, in specific regions, Kw was significantly higher in the PA group compared to controls: left rectus (P = 0.004), left posterior cingulate (P = 0.014), right posterior cingulate (P = 0.005), right cuneus (P = 0.010), right superior occipital (P = 0.046), and right angular (P = 0.023). Additionally, Kw in the right parahippocampal gyrus was significantly higher in PA than in EH (P = 0.026). In the PA group, plasma aldosterone correlated positively with Kw in the cuneus_R (r = 0.507, P = 0.032).
Conclusion
PA is associated with increased BBB permeability in distinct cerebral regions, which may be a key pathological mechanism underlying the higher presence of CMBs in this population. The positive correlation between plasma aldosterone and regional Kw suggests that excessive aldosterone may directly contribute to regional BBB imparement. These findings provide new insights into the cerebrovascular consequences of aldosterone excess.Figure 1Figure 2