Age- and sex-related differences in cortical morphology and their relationships with cognitive performance in healthy middle-aged and older adults

Abstract

Background The impacts of age and sex on brain structures related to cognitive function may be important for understanding the role of aging in Alzheimer disease for both sexes. We intended to investigate the age and sex differences of cortical morphology in middle-aged and older adults and their relationships with the decline of cognitive function. Methods In this cross-sectional study, we examined the cortical morphology in 204 healthy middle-aged and older adult participants aged 45 to 89 years using structural magnetic resonance imaging (sMRI) data from the Dallas Lifespan Brain Study data set. Brain cortical thickness, surface complexity, and gyrification index were analyzed through a completely automated surface-based morphometric analysis using the CAT12 toolbox. Furthermore, we explored the correlation between cortical morphology differences and test scores for processing speed and working memory. Results There were no significant interactions of age and sex with cortical thickness, fractal dimension, or gyrification index. Rather, we found that both males and females showed age-related decreases in cortical thickness, fractal dimension, and gyrification index. There were significant sex differences in the fractal dimension in middle-aged participants and the gyrification index in older adult participants. In addition, there were significant positive correlations between the cortical thickness of the right superior frontal gyrus and Wechsler Adult Intelligence Scale (WAIS)-III Letter-Number Sequencing test scores in males (r=0.394; P<0.001; 95% CI for r values 0.216–0.577) and females (r=0.344; P<0.001; 95% CI for r values 0.197–0.491), respectively. Furthermore, a significant relationship between the gyrification index of the right supramarginal gyrus (SupraMG) and WAIS-III Digit Symbol test scores was observed in older adult participants (r=0.375; P<0.001; 95% CI for r values 0.203–0.522). Conclusions The results suggest that, compared with males, females have more extensive differences in cortical morphology. The gyrification index of the right SupraMG can be used as an imaging marker of sexual cognitive differences between males and females in older adults. This study helps to further understand sex differences in the aging of the brain and cognition.

Cortical gyrification in women and men and the (missing) link to prenatal androgens

“…With respect to the presence and direction of the observed sex effect (women > men), the current findings confirm some prior studies, which reported an increased gyrification in females compared to males in parietal regions (Gautam et al, 2015), frontal and parietal regions (Cui et al, 2023;Luders et al, 2004), or frontal, parietal, temporal and occipital regions (Luders et al, 2006). With respect to the location of the sex effect, there is a striking correspondence with the outcomes of another recent study (Cui et al, 2023) based on 204 healthy adults (127 women / 77 men): More specifically, when investigating the gyrification index, Cui et al ( 2023) reported very similar regions where women had increased measures compared to men (see fig. 4 in Cui et al, 2023).…”

What it is like to be an older person with memory complaints: the perception of women seen at a Physical Rehabilitation Center

“…Family caregivers of older people with memory problems report that the elders put themselves in danger involving situations such as lighting the gas stove and forgetting to turn it off and handling saucepans on the hotplate. Symptoms of cognitive decline can include problems remembering names, word-finding difficulties when trying to describe something, and mislaying objects 6 .…”

“…Aging is accompanied by decline in processing speed, attention span, episodic recall ability and execution of different tasks [3][4][5] . Memory complaints in older individuals are more prevalent among women 6,7 .…”

Age-specific sex effects in extinction of conditioned fear in rodents

“…The PFC is a critical region for age-specific extinction (Ganella et al, 2017b;Kim et al, 2017;Zbukvic et al, 2017;Zbukvic and Kim, 2018;Perry et al, 2021). In humans, the PFC is one of the first to atrophy in aging, which is consistently related to reduced cognitive flexibility (Armstrong et al, 2019;Cui et al, 2023). Extinction could be considered a test of cognitive flexibility because it involves the flexible retrieval of the fear memory or the extinction memory depending on the appropriate circumstance (Kaczorowski et al, 2012;Short et al, 2022).…”