Vitamin D Concentration and Motoric Cognitive Risk in Older Adults: Results from the Gait and Alzheimer Interactions Tracking (GAIT) Cohort

Background. Motoric Cognitive Risk (MCR) syndrome, which combines subjective memory complaint (SMC) and slower gait speed, is a newly-described predementia stage. Based on the involvement of vitamin D in the biology of both gait and cognition, we hypothesized that nondemented individuals with MCR would exhibit hypovitaminosis D more often compared to Cognitively Healthy Individuals (CHI). The objective of this cross-sectional analysis was to determine whether hypovitaminosis D was associated with MCR. Methods. Participants without dementia from the GAIT (Gait and Alzheimer Interactions Tracking) cohort study were classified into MCR or Cognitively Healthy Individuals (CHI) groups. Hypovitaminosis D was defined as the lowest quartile of serum 25-hydroxyvitamin D (25OHD) concentration compared to the other three combined. Age, sex, body mass index (BMI), the Frontal Assessment Battery (FAB) score, the Mini-Mental Short Examination (MMSE) score, education level, use of psychoactive drugs, and the number of chronic diseases were used as covariates. Results. Among 244 nondemented and nonMCInonMCR participants from the GAIT cohort (mean age 71.4 ± 3.7 years, 40.6% women), 66 participants were classified as MCR (36.9%) and 178 as CHI (63.1%). The lowest quartile of 25OHD concentration was directly associated with MCR (unadjusted OR = 2.85, p = 0.003) even after adjustment for studied potential confounders (fully adjusted OR = 2.61, p = 0.025). The BMI (adjusted OR = 6.65, p < 0.001), MMSE score (adjusted OR = 0.74, p = 0.009), FAB score (adjusted OR = 0.51, p < 0.001), number of chronic diseases (adjusted OR = 1.29, p = 0.043) and use of psychoactive drugs (adjusted OR = 2.55, p = 0.044) were also associated with MCR. Conclusions. Hypovitaminosis D was associated with MCR in older community-dwellers without dementia.