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

Abstract

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