Effects of head circumference and metabolic syndrome on cognitive decline.

Abstract

Brain volume progressively decreases with an increase in atrophy, and the brain becomes more susceptible to degenerative brain diseases such as Alzheimer's disease. Metabolic syndrome has also been associated with an increased risk of cognitive decline in the elderly. Aims: In this study, we aimed to examine the effects of head circumference and metabolic syndrome on cognitive decline.

METHODS: This study was part of a longitudinal study conducted on Koreans aged 60 years or older. We analyzed a final sample of 596 Korean participants with complete baseline and 2-year follow-up data. The cognitive function of the subjects was assessed using the Korean version of the Mini Mental State Examination (MMSE). Head circumference was measured from the glabella to the occipital protuberance using a measuring tape. Metabolic syndrome was defined according to the NCEP-ATP III standards. Central obesity was assessed on the basis of waist-circumference values, in accordance with the World Health Organization Western Pacific Region report on Asians. We used a longitudinal factorial design in which the MMSE score was the dependent variable, and head circumference and metabolic syndrome were considered as factors.

RESULTS: After adjusting the results for age, gender, education, height, weight, baseline MMSE, and number of follow-up years, we observed that smaller head circumference and the presence of metabolic syndrome were independently associated with rapid cognitive decline.

CONCLUSION: All these findings suggest that smaller head circumference and the presence of metabolic syndrome have additive effects on cognitive decline.