RESUMO
The choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) are fundamental to neurophysiological functions of the central cholinergic system. We confirmed and quantified the presence of extracellular ChAT protein in human plasma and also characterized ChAT and VAChT polymorphisms, protein and activity levels in plasma of Alzheimer's disease patients (AD; N = 112) and in cognitively healthy controls (EC; N = 118). We found no significant differences in plasma levels of ChAT activity and protein between AD and EC groups. Although no differences were observed in plasma ChAT activity and protein concentration among ChEI-treated and untreated AD patients, ChAT activity and protein levels variance in plasma were higher among the rivastigmine-treated group (ChAT protein: p = 0.005; ChAT activity: p = 0.0002). Moreover, AD patients homozygous for SNP rs1880676 A allele exhibited higher levels of ChAT activity. Considering this is the first study to report the influence of genetic variability of CHAT locus over ChAT activity in AD patients plasma, it opens a new set of important questions on peripheral cholinergic signaling in AD.
RESUMO
Objetivos: Avaliar a relação entre a função cognitiva, equilíbrio, risco de quedas e funcionalidade em idosos com alteração da função cognitiva e verificar se os idosos com comprometimento cognitivo leve apresentam melhor equilíbrio, funcionalidade e menor risco de quedas em relação aos idosos com demência.Métodos: Estudo transversal analítico realizado com 33 idosos, ambos os gêneros, com idade igual ou superior a 60 anos, avaliados por meio dos testes: Miniexame do Estado Mental (MEEM), Timed Up and Go (TUG), Escala de Equilíbrio Funcional de Berg (EEFB), Escala de Avaliação Clínica da Demência (CDR) e Índice de Barthel. Foram considerados quatro grupos: comprometimento cognitivo leve (CCL; n=9), demência leve (DL; n=12), demência moderada (DM;: n=7) e demência grave (DG; n=5). A comparação dos dados foi realizada pelo teste de U Mann Whitney e a correlação, pelo Coeficiente de Correlação de Spearman, com nível de significância de 5% (p<0,05). Resultados: Ocorreu diferença estatística significativa no risco de quedas e funcionalidade entre os grupos DL e DM; funcionalidade entre os grupos DM e DG; equilíbrio, funcionalidade e risco de quedas entre os grupos DL e DG. Observou-se correlação moderada do MEEM e EEFB (r=0,543; p=0,006) no grupo CCL, correlação moderada negativa entre o MEEM e TUG (r=-0,685; p<0,001) e forte correlação do MEEM e Barthel (r=0,708; p<0,001) no grupo demência.Conclusão: A piora da função cognitiva esteve associada ao maior comprometimento da funcionalidade, equilíbrio e aumento do risco de quedas nos idosos com demência em comparação aos idosos com comprometimento cognitivo leve.
Objective: To assess the relationship between cognitive function, balance, risk of falls and functionality in elderly persons with impaired cognitive function and verify if those with mild cognitive impairment had better balance, functionality and a lower risk of falls than those with dementia.Methods: An analytical cross-sectional study of 33 elderly persons of both genders, aged over 60 years, were evaluated using the Mini Mental State Examination (MMSE), Timed Up and Go (TUG) test, Berg Balance Scale (BBS), Clinical Dementia Rating Scale (CDR) and Barthel Index. Four groups were considered: mild cognitive impairment (MCI; n=9), mild dementia (MID; n=12), moderate dementia (MOD; n=7) and severe dementia (SD; n=5). Data comparison was performed by the Mann Whitney U-test and correlation by Spearman's rank Correlation Coefficient, whit a significance level of (p<0.05).Results: There was a statistically significant difference in the risk of falls and functionality between the MID and MOD groups, functionality between the MOD and SD groups, and balance, functionality and risk of falls between the MID and SD groups. A moderate correlation between MMSE and BBS (r=0.543; p=0.006) was observed in the MCI group, and a moderate negative correlation between MMSE and TUG (r=-0.685; p<0.001) and a strong correlation between MMSE and Barthel (r=0.708; p<0.001) were observed in the dementia group.Conclusion: The deterioration in cognitive function was associated with greater impairment of functionality, balance and an increased risk of falls in elderly persons with dementia, compared to elderly subjects with mild cognitive impairment.
