Association of interleukin-1β genetic polymorphisms with cognitive performance in elderly females without dementia.

Interleukin-1β (IL-1β) is considered to have a role in age-related cognitive decline. A recent study has shown that a promoter polymorphism of the IL-1β gene (rs16944) is associated with cognitive performance in elderly males without dementia. In this study, we examined whether polymorphisms of the IL-1β gene also influence cognitive functions in elderly females. Cognitive functions were assessed by the Wechsler adult intelligence scale-revised (WAIS-R) in 99 elderly (60 years) females without dementia. We selected five tagging polymorphisms from the IL-1β gene and examined the associations with the WAIS-R scores. Significant associations were found between verbal intelligence quotient (IQ) and the genotypes of rs1143634 and rs1143633 (P=0.0037 and P=0.010, respectively). No significant associations of rs16944 genotype were found with verbal or performance IQ. However, individuals homozygous for the G allele of rs16944 achieved higher scores in digit span compared with their counterpart, which is consistent with the previous findings in males. These results suggest that IL-1β gene variation may have a role in cognitive functions in aging females as well as males.