Physical inactivity and cognitive impairment in Korean older adults: gender differences in potential covariates

Background: Physical inactivity is one major lifestyle risk factor of mild cognitive impairment with ageing.Aim: To investigate whether or not potential covariates modulate the association between physical activity (PA) and cognitive impairment in older adults.Subjects and methods: Data from 10245 Korean older adults (5817 women) were used.Results: High PA older adults were younger and longer educated and had lower comorbidity and depression than low PA older adults. Compared with low PA men, moderate PA men only had a significantly lower odds-ratio (OR) and 95% confidence interval (95% CI) (OR=0.795, 95% CI=0.654 approximate to 0.965, p=0.021) for having cognitive impairment, even after adjusting for measured covariates, which was no longer significant when additionally adjusted for comorbidity (OR=0.862, 95% CI=0.707 approximate to 1.051, p=0.143). Compared with low PA women, moderate and high PA women had significantly lower risks of cognitive impairment (OR=0.830, 95% CI=0.712 approximate to 0.969, p=0.018 and OR=0.784, 95% CI=0.651 approximate to 0.943, p=0.010, respectively), even after adjusting for the measured covariates including comorbidity, which was no longer significant when additionally adjusted for depression (OR=0.897, 95% CI=0.776 approximate to 1.049, p=0.173 and OR=0.919, 95% CI=0.761 approximate to 1.111, p=0.385, respectively).Conclusion: These findings suggest that gender differences in the covariates modulate the relationship between physical activity and cognitive decline in older Korean adults.