Deterioration of spinal sagittal alignment exposes latent cognitive impairment in the general older population: A Japanese cohort survey randomly sampled from a basic resident registry

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background: </jats:bold>This study investigated the impact of spinal sagittal alignment on cognitive function in the general older population using a Japanese population cohort constructed from random sampling of the basic resident registry of a rural town.<jats:bold>Methods: </jats:bold>Registered citizens of 50 to 89 years old were targeted for this survey. Participants were classified into 8 groups based on age (50's, 60's, 70's, or 80's) and sex (male or female) after random sampling from the resident registry of a cooperating town in 2014. A total of 413 subjects (203 male and 210 female) were enrolled. We analyzed the distribution of cognitive function test scores determined as by Montreal Cognitive Assessment and Mini-Mental State Examination in each age and sex group to assess the impact of radiographic parameters of spinal sagittal alignment on cognitive function tests.<jats:bold>Results: </jats:bold>Cognitive function test results tended to decrease with age. Among groups of the same age and sex, cognitive function worsened significantly with poorer spinal alignment. In particular, increases in sagittal vertical axis or global tilt by 1 degree of standard deviation were significantly related to mild cognitive impairment (odds ratio: both 1.4).<jats:bold>Conclusions: </jats:bold>Spinal alignment deterioration indicated cognitive function decline in Japanese older people of the same age and sex. Thus, a forward shift in sagittal spinal balance may be regarded as a visible indicator of latent mild cognitive impairment in community-dwelling older people.</jats:p>