Spatial concordance metrics and related risk factors of brain-peripheral barrier axes: unveiling distinct concordance patterns for mental and neurological axes.

Abstract

Numerous studies have documented bidirectional interactions between the central nervous system and barrier organs (skin, gut, and lung). While genome-wide association studies have revealed shared genetic factors across brain-peripheral barrier axes, investigating these connections from an environmental perspective in large populations remains difficult. Using data from the Global Burden of Disease (GBD) 2023, I extracted annual incidence rates for 56 diseases related to brain-peripheral barrier axes and exposure rates for the 70 most detailed risk factors across 204 countries and territories. By categorizing regional incidence rates into four quartiles for each disease, I pinpointed regions with concordance of these axes and constructed a spatial atlas of disease concordance within the brain-peripheral barrier axis from a macro-epidemiologic view. Subsequently, I calculated global spatial concordance percentages for each axis, which allowed the comparatively assessment of concordance patterns across different axes, specific diseases, and their variations over time, across the lifespan, and by gender. Finally, I applied machine learning models and Shapley additive explanations to identify risk factors related to the spatial concordance of each axis. From 1990 to 2023, the overall trend for most brain-peripheral barrier axis pairs remained stable. Spatial concordance patterns showed dynamic fluctuations across the lifespan, followed by a convergence toward stability in older age. Several risk factors are related to most brain-peripheral barrier axes. Notably, the mental and neurological axes exhibited distinct concordance patterns. Compared with neurological axes, concordance within mental axes showed a broader and more dispersed geographic distribution, with greater variation across sexes and over time. Furthermore, concordance percentages of mental and neurological axes exhibited opposing age-related trends, contrasting disease spectra for peripheral conditions, and inverse relationships with alcohol and sodium consumption. Those divergences suggest distinct mechanisms underlying the brain-peripheral barrier axes in mental and neurological diseases. Related risk factors offer population-based hypotheses for further investigation in individual-level studies.