Associations between salivary testosterone levels and cognitive function among 70-year-old Japanese elderly: A cross-sectional analysis of the SONIC study.

Abstract

This cross-sectional study aimed to investigate the associations between salivary testosterone concentrations and cognitive function in 70-year-old Japanese elderly people without dementia and stroke. Participants were 197 Japanese community-dwelling people aged 69-71 years. Their salivary samples were collected, and their cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Participants were also administered a 10-item recall and a 24-item recognition test. The data for 179 (106 men and 73 women) individuals were analyzed, excluding individuals with a past history of stroke and dementia. Multivariate logistic regression analyses were performed after adjusting for lifestyle factors and analyzing data separately for men and women. MoCA-J scores showed that men with low testosterone concentrations had a significantly greater risk of low cognitive performance than those with high testosterone concentrations (adjusted odds ratio: 4.72, 95% confidence interval: 1.06-21.00), while no significant association was found in women. The 10-item recall test scores showed that higher testosterone concentrations were significantly associated with greater recall in the second trial in women (standardized beta=0.24, P=0.040), whereas no significant association was found in men. Salivary testosterone concentrations were positively associated with better cognitive performance in older men and women. The associations between salivary testosterone concentrations and cognitive function were shown by different tasks for men and women. Geriatr Gerontol Int 2022; 22: 1040-1046.