Prevalence of mild cognitive impairment in an urban community in China: a cross-sectional analysis of the Shanghai Aging Study.

Background: Substantial variations in the prevalence of mild cognitive impairment (MCI) have been reported, although mostly in Western countries. Less is known about MCI in the Chinese population.

Methods: We clinically and neuropsychologically evaluated 3141 community residents ≥60 years of age. Diagnoses of MCI and its subtypes were made using standard criteria via consensus diagnosis.

Results: Among 2985 nondemented individuals, 601 were diagnosed with MCI, resulting in a prevalence of 20.1% for total MCI, 13.2% for amnestic MCI (aMCI), and 7.0% for non-amnestic MCI (naMCI). The proportions of MCI subtypes were: aMCI single domain (SD), 38.9%; aMCI multiple domains (MD), 26.5%; naMCI-SD, 25.0%; and naMCI-MD, 9.6%. The prevalence of aMCI-MD increased rapidly with age in women APOE ε4 carriers (from 60 to 69 years to ≥80 years, 3.1%-33.3%, P < .001).

Conclusions: Our findings suggest that 20% of Chinese elderly are affected by MCI. Prospective studies in China are needed to examine progression to dementia and related risk factors.