Investigation of risk factors for the conversion of mild cognitive impairment to dementia

Abstract

Background

Mild cognitive impairment (MCI) is an intermediate state between normal aging and dementia and is characterized by pathological cognitive decline. The study aimed at revealing the risk of MCI progressing to dementia through a follow-up investigation.

Methods

In 2011, 441 MCI subjects were recruited, and the disease status was tracked by the follow-up survey in 2017. Subjects with MCI stable (MCIs; N = 356) and MCI progressed into dementia (MCIp; N = 77) were analysed in our study. Community-dwelling old people of age ≥ 55 were recruited from 30 streets and 24 committees (or communities) of the Pudong New District (Shanghai, China). Neuropsychological tests of MMSE, MoCA, 17-item HAMD-17, ADL and HIS were performed. Additionally, the correlations of neuropsychological items and MCIp were explored by univariate and multivariate regression analyses.

Results

MCIp patients had the lower MMSE and MoCA total scores, whereas the ADL, and HIS total score in MCIp group were higher than in MCIs group. The univariate analysis revealed age, attention (MoCA), visuospatial/executive, number of births, marital status and attention and calculation were significant predictors of MCI progression. In multivariate analysis, age was an independent risk factor of MCI aggravating, while attention (MoCA) was independent protective factor for MCI progression.

Conclusions

Age and worsening attention but not depression in MCI patients were independently associated with the progression of dementia in a 6-year follow-up period.

Keywords:

• Mild cognitive impairment
• dementia
• neuropsychological test
• executive function
• attention

Acknowledgements

Epidemiological investigation tasks are complex and tedious. First of all, thank the research team in 2011 for their hard work and created a better basis for follow-up research. Second, thank you to the staff in the towns who assisted our team in the investigation and organization of the residents during the research process. At the same time, thank each member of the research team for their dedication, seriousness and pragmatic work spirit, overcoming various difficulties encountered during the investigation, and completing the data collection and input finishing. Thanks Ying Lu and Wei Guo for their help in data collection, and Zhicheng Cao for their help in analysing and interpreting the data. Finally, thank the leaders and staff of the centre for their selfless guidance and assistance in this subject.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

The study was approved by the Ethics Committee of Shanghai Pudong New Area Mental Health Center.

Informed consent

The informed consents were obtained from all participants.

Data availability statement

All data generated or analysed during this study are included in this published article.

Authors’ contributions

Conception and design of the research: CH and MT; analysis and interpretation of data: LW; statistical analysis: LW; statistical analysis: XZ and BZ; obtaining funding: CH, XZ and MT; drafting the manuscript: HQ; revision of manuscript for important intellectual content: HQ. All authors read and approved the final manuscript.

Additional information

Funding

This work was supported by Shanghai Pudong Municipal Commission [grant number: PWZxk2017-17, PWgy2018-10], National Natural Science Foundation of China [grant number: 81670752].