Conceitos essenciais
The blood-brain barrier (BBB) function declines with aging, and this decline is more pronounced in males compared to females, especially in specific brain regions like the lateral prefrontal cortex, parietal cortex, and temporal lobes.
Resumo
This study investigated the spatiotemporal trajectories of cerebral blood flow (CBF), arterial transit time (ATT), and BBB water exchange rate (kw) across the lifespan in 186 cognitively normal participants aged 8 to 92 years, using a non-invasive diffusion-prepared pseudo-continuous arterial spin labeling (DP-pCASL) MRI technique.
Key findings:
- BBB kw remained relatively stable until the early 60s, after which a marked decline was observed, especially in males.
- Sex differences in kw decline were most pronounced in the lateral prefrontal cortex, parietal cortex, and temporal lobes.
- While CBF decreased and ATT increased with aging in both sexes, the rates of change were largely consistent between males and females, except for a more rapid CBF decrease in males within the hippocampus.
- The observed sex differences in BBB function decline may contribute to the differential susceptibility to neurological disorders between males and females.
- The DP-pCASL technique provides a non-invasive approach to probe the mechanisms underlying age and sex-related changes in BBB function, potentially enabling early detection and intervention for cognitive decline and neurodegenerative disorders.
Estatísticas
Whole-brain average kw values for males were 120.7±17.4, 117.5±26.5, and 97.9±31.4 min-1 across the 3 age groups (8-35 years, 36-61 years, 62-92 years), while females' kw values were 121.7±18.2, 118.9±14.0, and 114.8±23.7 min-1, respectively.
Whole-brain average ATT values were 1325.8±157.7, 1383.9±199.6, and 1526.7±117.4 ms for males, and 1220.2±134.2, 1334.4±155.4, and 1468.1±166.9 ms for females across the three age groups.
Whole-brain average CBF values were 51.5±11.9, 43.9±10.7, and 31.9±8.5 ml/100g/min for males, and 60.5±10.7, 51.2±11.7, and 39.6±10.3 ml/100g/min for females from young to middle age to elderly groups.
Citações
"The blood-brain barrier (BBB) serves as a critical protection mechanism for the CNS. A natural decline of BBB function with aging has been reported in both animal and human studies, with possible differences in BBB function by sex."
"We observed a distinct trajectory of kw changes with aging as compared to CBF and ATT. The kw remained relatively stable throughout early to mid-adulthood, with a marked decline in the early 60s, especially in males (∽18%)."
"The most intriguing finding of our study is that BBB kw declines faster in males compared to females in specific brain regions including lateral prefrontal and parietal cortex, as well as lateral and medial temporal lobes."