Impact of chronic diseases and associated medications on thiamine metabolism in the non-demented elderly.

OBJECTIVE: to evaluate the interplay among chronic diseases, pharmacotherapy, and apolipoprotein E (APOE) genotype on thiamine homeostasis in non-demented elderly individuals. METHODS: in this community-based cross-sectional study, we recruited 1322 cognitively normal elderly (578 males, 744 females) aged over 60 years from Xuhui District, Shanghai. Demographic characteristics of disease and medication history were collected by questionnaires. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). APOE genotyping was identified using single nucleotide polymorphism analysis. Thiamine diphosphate (TDP), thiamine monophosphate (TMP), and free thiamine (FT) were measured by high-performance liquid chromatography (HPLC). RESULTS: a total of 281 APOE ε4 carriers and 1041 non-carriers were enrolled in this study. All of participants had an average educational background of over 9 years and a MMSE score of 27.90 ± 2.35. Disease subgroups were classified as follows: hypertension (37.5 %, n = 496), diabetes (5.75 %, n = 76), hypertension with diabetes (8.02 %, n = 106), cardiovascular disease (4.31 %, n = 57), and multimorbidity subgroups. There were no significant differences in TDP levels between healthy controls and all of the disease subgroups in non-demented elderly. Furthermore, the pharmacotherapy also showed no significant effects on TDP levels under those disease condition. Additionally, both APOE ε4 carriers and non-carriers within each of the disease subgroups exerted comparable TDP levels. CONCLUSION: our results indicated that common chronic diseases and their standard pharmacotherapy do not significantly alter thiamine metabolism in non-demented elderly. The APOE ε4 genotype shows no modifying effect on thiamine homeostasis in this population, regardless of the presence or absence of disease comorbidity.