Limb length and dementia in an older Korean population.

OBJECTIVES There has been little research into risk factors for dementia outside Western settings, in particular the importance of early life nutrition as estimated by adult body size. This study investigated the associations of arm and leg length with cognitive impairment and dementia in a community sample of older Korean people. METHODS 746 community residents aged 65 or over were clinically assessed for dementia and cognitive impairment. The following were also measured: arm length (demispan), leg length (iliac crest height), and sitting height (standing height minus iliac crest height). Reproductive history was also ascertained in women. RESULTS Shorter demispan and leg length were associated with increased age and lower education. They were also associated with dementia and Alzheimer's disease after adjustment for these factors. These associations were only significant in women but were not explained substantially by timing of the menarche or menopause. The association between lower education and dementia was also stronger in women, but was not explained substantially by limb length. CONCLUSIONS Shorter limb length was associated with lower childhood socioeconomic status, as estimated by the presence/duration of formal education. It was also independently associated with dementia and Alzheimer's disease. Sex differences in this association might be explained by gender disadvantage in early life for this cohort or by different associations with health states (for example, cardiovascular disease) later in life.