A follow-up study on cognitive changes in the elderly with lower Minimum Mental State Examination scores of the elderly in community

Abstract

Objective To explore the cognitive change in lower MMSE scores of the elderly. Methods From Sep 2001 to Feb 2002, 5 276 persons aged 55 years or over living in urban and rural areas of Guangzhou were investigated by Senile Dementia Screening Questionaire, Senile Dementia Diagnosis, in which 917 were diagnosed with low MMSE scores (183 dementia patients, 264 mild cognitive impairment (MCI) people and 470 normal were differentiated in reexamination). MCI and normal people followed up in 2003 and 2008 with the same tools. Results (1) In comparison between interviewers who finished the interview (n=303) and lost interviews (n=332); the average age in lost interviews were older than the finidhed (t=-5.14, P<0.05) in second follow-up study. In the second follow-up, urban old people (n=488) had higher lost rate than the rural elderly(n=147; χ2=21.92, P<0.05) and no statistical significant difference were found in the other personal characteristics in both follow-up study. (2) The incidence of dementia and Alzheimer's disease(AD) among MCI were 9.42/100 person-year and 7.46/100 person-year respectively. The incidence of dementia, AD, MCI among normal were 3.05/100, 2.21/100 and 6.28/100 person-year respectively. (3) Those risk factors increased the progression from the normal to MCI were aged (RR=1.28, 95% CI 1.09-1.51) ,stroke (RR=2.23, 95% CI 1.11-4.51). The risk factors increased the progression from the normal to AD were female (RR=2.87, 95% CI 1.17-7.04) , aged (RR=1.70, 95% CI 1.27-2.27). The risk factors increased the progression from the normal to VD were stroke (RR=9.15 95% CI 2.16-38.74). The risk factors increased the progression from the MCI to AD were aged (RR=1.48, 95% CI 1.17-1.86). Those risk factors increased the progression from the MCI to VD: hypertentsion (RR=4.43, 95% CI 1.00-19.53 ) , stroke (RR=7.21, 95% CI 1.88-27.57 ). Conclusions The lower MMSE scores of the elderly in community are the risk factor for dementia. The older, stroke in lower MMSE scores elderly may have higher risk progression to MCI. The olderage in lower MMSE scores of the elderly, female could be higher risk progression to AD. The hypertension and stroke in lower MMSE scores of the elderly may have higher risk progression to VD. Key words: Alzheimer's disease; Dementia; Follow-up studies; Mild cognitive impairment; Minimum Mental State Examination