Background: Hypertension-related illnesses are a leading cause of disability and death in the United States, where hypertension prevalence in adults is 46%, with only half of those afflicted having it under control. Due to the significant challenges in long-term efficacy and adverse effects associated with pharmacological interventions, there is an eminent need for complimentary approaches for treating hypertension. Although initial studies of the Mindfulness-Based Blood Pressure Reduction program (MB-BP) indicate that this novel 8-week intervention is effective at inducing lasting decreases in blood pressure, the neural correlates are unknown.
Methods: The objectives of this study were to identify structural neural correlates of MB-BP using diffusion tensor magnetic resonance imaging (DTI) and assess potential correlations with key clinical outcomes.
Results: In a subset of participants (14 MB-BP, 22 controls) from a larger stage IIa randomized controlled trial, MB-BP participants exhibited increased interoception and decreased depressive symptoms compared to controls. Analyses of DTI data revealed significant group differences in multiple white matter neural tracts associated with the limbic system and/or blood pressure. Specific changes in neural structural connectivity were significantly associated with measures of interoception and depression.
Limitations: Limitations include small sample size (leading to insufficient power in the analysis of blood pressure) and the study duration (3 months). The main MRI limitation is suboptimal resolution in areas of extensive neural tract crossings.
Conclusions: It is concluded that MB-BP induces alterations in brain structural connectivity which could mediate beneficial changes in depression and interoceptive awareness in individuals with hypertension.
Trial registration: ClinicalTrials.gov NCT03256890.
Keywords: Depression; Diffusion tensor imaging; Hypertension; Interoception; MRI; Mindfulness.
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