RESUMO
We investigated the effect of age and health variables known to modulate cognitive aging on several measures of cognitive performance and brain volume in a cohort of healthy, non-demented persons of Chinese descent aged between 55 and 86 years. 248 subjects contributed combined neuropsychological, MR imaging, health and socio-demographic information. Speed of processing showed the largest age-related decline. Education and plasma homocysteine levels modulated age-related decline in cognitive performance. Total cerebral volume declined at an annual rate of 0.4%/yr. Gray and white matter volume loss was comparable in magnitude. Regionally, there was relatively greater volume loss in the lateral prefrontal cortex bilaterally, around the primary visual cortex as well as bilateral superior parietal cortices. Speed of processing showed significant positive correlation with gray matter volume in several frontal, parietal and midline occipital regions bilaterally. In spite of differences in diet, lifestyle and culture, these findings are broadly comparable to studies conducted in Caucasian populations and suggest generalizability of processes involved in age-related decline in cognition and brain volume.
