Association of vitamin D deficiency with cognitive impairment in older women

Abstract

<b>Objective:</b> The association between low serum 25-hydroxyvitamin D [25(OH)D] concentration and cognitive decline has been investigated by only a few studies, with mixed results. The objective of this cross-sectional population-based study was to examine the association between serum 25(OH)D deficiency and cognitive impairment while taking confounders into account. <b>Methods:</b> The subjects, 752 women aged ≥75 years from the Epidémiologie de l9Ostéoporose (EPIDOS) cohort, were divided into 2 groups according to serum 25(OH)D concentrations (either deficient, &lt;10 ng/mL, or nondeficient, ≥10 ng/mL). Cognitive impairment was defined as a Pfeiffer Short Portable Mental State Questionnaire (SPMSQ) score &lt;8. Age, body mass index, number of chronic diseases, hypertension, depression, use of psychoactive drugs, education level, regular physical activity, and serum intact parathyroid hormone and calcium were used as potential confounders. <b>Results:</b> Compared with women with serum 25(OH)D concentrations ≥10 ng/mL (n = 623), the women with 25(OH)D deficiency (n = 129) had a lower mean SPMSQ score (<i>p</i> &lt; 0.001) and more often had an SPMSQ score &lt;8 (<i>p</i> = 0.006). There was no significant linear association between serum 25(OH)D concentration and SPMSQ score (β = −0.003, 95% confidence interval −0.012 to 0.006, <i>p</i> = 0.512). However, serum 25(OH)D deficiency was associated with cognitive impairment (crude odds ratio [OR] = 2.08 with <i>p</i> = 0.007; adjusted OR = 1.99 with <i>p</i> = 0.017 for full model; and adjusted OR = 2.03 with <i>p</i> = 0.012 for stepwise backward model). <b>Conclusions:</b> 25-Hydroxyvitamin D deficiency was associated with cognitive impairment in this cohort of community-dwelling older women.