Brain Volume Metric Analysis Is Correlated with Aging Changes and Sex Differences in Thai Older Adults

Normative data on structural brain volume changes with age and sex differences are required as a reference standard for future research and clinical use.

We studied a two-center, metropolitan-based, prospective cohort of adults aged 55 years and older who were recruited from community-dwelling settings and outpatient clinics without cognitive impairment at baseline and who were followed up for 2 years. The clinical data, neuropsychological tests, and brain MRI obtained with FreeSurfer software were utilized for quantitative volumetric measurements.

A total of 296 participants were recruited at the beginning, with 17 participants (5.8%, excluding 2 subjects with claustrophobia) excluded due to abnormal MRI findings and 27 participants (9.1%) excluded due to MCI/dementia. Among the 250 remaining, 14 patients dropped out or were lost to follow-up, and 35 had MCI or AD converters (14.8%). The remaining 201 subjects with normal cognitive function aged 55-85 years were analyzed for structural brain volume. There were significant correlations between age and brain parameters, including the hippocampus, corpus callosum, thalamus, and ventricular volume changes (p value <0.05). There were significant differences between males and females in total intracranial volume, caudate, temporal lobe, and ventricle volumes in subjects aged 65-74 years, and in total intracranial volume and ventricle volumes in subjects aged 55-64 years (p value <0.05).

Age and sex contributed to differences in brain structure and ventricular volume. These data could be used as a normative reference for clinical interpretation in people up to 85 years old and for understanding the physiological aging-related changes in the brain.