A Study On The Rate Of Alzheimer’s Disease And Relations With Vitamin A Among The Elderly Population In Social Welfare Institutions Of Chongqing, China

ObjectiveTo investigate the rate of Alzheimer’s disease, vitamin A status, the relationship between them, and the influence of vitamin A on Alzheimer’s disease among the elderly population in social welfare institutions of Chongqing.Subjects and MethodsThe methods of cluster sampling were adopted and the questionnaire, physical examination and the determination of serum retinol were administered to the elders volunteers in twelve social welfare institutions in Chongqing, China. The cognitive function was evaluated by Hachinski ischemic score(HIS), Hamiltion rating scale for depression(HRSD), mini-mental state examination(MMSE), activity of daily living scale&instrumental activity of daily living scale(ADL&IADL), Alzheimer’s disease assessment scale(ADAS), clinical dementia rating(CDR) and the serum concentration of vitamin A was determined by high performance liquid chromatography(HPLC). A total of322subjects were recruited into the present study. They were assigned to normal cognitive function, mild cognitive impairment, medium cognitive impairment groups and vitamin A normal(VAN), marginal vitamin A deficiency(MVAD), and vitamin A deficiency(VAD) groups.Results1. Female subjects(79.59±7.52years) were about5years older than males subjects(75.08±8.82years) among the elders volunteers in this study(P<0.01). Constituent ratio of cognitive impairment groups was found to be high(55.9%). The scores of cognitive function scales were worse in older age group(85-95years) than in younger age groups(65-75years and75-85years), and ADL, IADL, ADAS, CDR was considered statistically significant(P<0.05).2. Constituent ratio of VAD(10.9%) and MVAD(30.1%) groups was found to be high. As the cognitive impairment progressed, constituent ratio of VAN in different cognitive function levels was lower than constituent ratio of MVAD and VAD(P<0.05). Serum vitamin A level in mild cognitive impairment group(1.07±0.38μmol/L) and medium cognitive impairment group(1.01±0.34μmol/L) were significant lower than in normal cognitive function group(1.33±0.37μmol/L)(P<0.05). The scores of MMSE, IADL, ADL, ADAS and CDR were all significant better in VAN group than in MVAD group(P<0.05). The scores of ADAS, CDR were also significant better in VAN than in VAD group(P<0.05). Serum vitamin A level and education level were found positively associated with the scores of MMSE and IADL(P<0.01), negatively associated with the scores of ADL, ADAS and CDR(P<0.05). Age was found positively associated with the scores of ADL, ADAS and CDR(P<0.05).ConclusionsOur data suggested that the prevalence of Alzheimer’s disease and vitamin A deficiency were ubiquitous among the elderly population in social welfare institutions in Chongqing. The aging and the lower education levels enhance the risk of Alzheimer’s disease. And low serum vitamin A status may aggratate cognitive impairment and enhance the risk of Alzheimer’s disease.