Morphometric brain changes during aging: Results from a Brazilian necropsy sample.

Area of Science:

• Neuroscience
• Gerontology
• Human Anatomy

Background:

• Aging is associated with various physiological changes, including alterations in brain structure.
• Understanding age-related morphometric brain changes and potential sex differences is crucial for geriatric health.
• Previous studies have indicated potential sex-based variations in brain aging, but further investigation is warranted.

Purpose of the Study:

• To investigate age-related morphometric changes in brain weight, volume, and density.
• To determine if sexual dimorphism influences these age-related brain alterations.
• To provide data from a Brazilian necropsy series.

Main Methods:

• A cross-sectional study utilizing necropsy data from the São Paulo Autopsy Service.
• Brain weight, volume, and density were measured and adjusted for head circumference.
• Statistical analyses included descriptive statistics, hypothesis testing, and correlation analyses (p<0.05).

Main Results:

• A total of 414 subjects (60.4% male, mean age 67.1 years) were analyzed.
• Mean brain weight was 1219.2g ± 140.9g, mean volume was 1217mL ± 152.3mL, and mean density was 1.0g/mL ± 0.09g/mL.
• Brain weight decreased by approximately 45g/decade (r=-0.300, p<0.01) and volume by 43mL/decade (r=-0.278, p<0.00), with greater reductions in women. Density remained consistent.

Conclusions:

• Brain weight and volume significantly decrease during aging, irrespective of head circumference correction.
• These reductions are more pronounced in females compared to males.
• Brain density remains stable throughout aging in both sexes, suggesting specific structural changes rather than overall tissue density alterations.