Cognitive Function and Vitamin D Status in the Chinese Hemodialysis Patients

Abstract

Objective. Vitamin D insufficiency and the cognitive function decline are both common in patients receiving hemodialysis (HD). The present study evaluated the relation between cognitive function and circulating vitamin D levels in HD patients in Wannan Medical College Affiliated Yijishan Hospital, China. Methods. This study was conducted in 80 patients receiving HD in Wannan Medical College Affiliated Yijishan Hospital. To measure cognitive function, Montreal Cognitive Assessment-Basic (MoCA-B) Chinese Version was used. The 25-hydroxyvitamin D [25(OH)D], which is applied to assess vitamin D status, was tested. One-way ANOVA, Tukey post hoc test, and the correlation and regression analysis were used in this study. Results. Based on the MoCA-B, cognitive function decline (the scores below 26) was present in 28 HD patients, accounting for 35% (28/80). The mean age of these patients is $50.5\pm 10.9$ years old. The mean level of 25(OH)D was $16.1\pm 7.3\text{ng}/\text{ml}$ in 80 HD patients. In univariate analysis, there was a significant relationship between MoCA-B score and serum 25(OH)D level ( $p<0.05$ ). The level of 25(OH)D was positively correlated with MoCA-B score ( $r=0.312$ , $p=0.023$ ), and the association was independent of demographic and clinical features. Conclusions. Vitamin D insufficiency may contribute to cognitive function decline in HD patients. Serum level of 25(OH)D is an independent protective factor of cognitive function in the HD patients.