Association between vitamin D and amyloid-related biomarkers levels in Mexican older adults

Abstract

Purpose: To determine the relationship between VD and Aβ-related biomarkers levels in Mexican older adults. Methods: 94 subjects >60 years old from a local daycare center in Colima, Mexico were enrolled in the study. All volunteers met the corresponding selection criteria and signed their informed consent. A blood sample was drawn from the participants for later ELISA analysis of VD and amyloid biomarkers. The study was approved by the Medical School Ethics Committee (Ref # 2019-02-02). Spearman correlation was performed to identify the relationship between VD and the other biomarkers, Chi-squared, and ANOVA/Kruskall Wallis for comparisons. Results: Serum VD inversely correlated with Aβ 42 (r = -0.372; p = 0.001), and positively with Aβ-40 (r = 0.252; p = 0.015). The prevalence of low VD levels(<75 nmol/L) was 66%, and 27.7% for deficiency (<50 nmol/L). The presence of low levels of VD was higher in women than in men (72.1% vs 50.0%, p = 0.043, OR = 1.331, IC95% = 0.972-1.822). When comparing VD categories, differences were found between those with deficiency and the subjects with sufficient levels regarding years of education, Aβ-40, and Aβ-42 levels (p = 0.023; p = 0.003; p = 0.020). Conclusion: An association between VD and Aβ serum levels was found; further studies are necessary to clarify the different types of correlations determined for each of the Aβ forms, so the participation of VDin AD development could be better explained regarding blood-based amyloid biomarkers. It would be highly recommended and interesting to integrate how the exercise could participate in this association.