Low folate and the risk of cognitive and functional deficits in the very old: the Monzino 80-plus study.

OBJECTIVE

To cross sectionally investigate the association of serum vitamin B(12) and folate concentrations with cognitive and functional ability in the very old in the general population.

METHODS

Serum vitamin B(12) and folate concentrations were assessed in 471 consenting subjects participating in the Monzino 80-plus study (mean age: 87.4 years), a door-to-door population-based survey among very old subjects living in Northern Italy. Cognitive and functional evaluations included Mini-Mental State Examination (MMSE), Instrumental Activities of Daily Living (IADL) and Spontaneous Behavior Interview-basic Activities of Daily Living (SBI-bADL).

RESULTS

MMSE, IADL and SBI-bADL scores were all significantly correlated with folate concentrations (respectively: r = 0.36, r = -0.39, r = -0.35; p < 0.0001), while no significant associations were found with vitamin B(12) concentrations. When entered into multiple linear regression analyses with several covariates, folate showed a highly significant, curvilinear association with both cognitive and functional scores (p < 0.0001). Subjects in low and middle folate tertiles had significantly higher odds ratios for dementia (p < 0.0001; adjusted ORs = 5.40 and 6.56, lower 95% CIs 2.53 and 3.11, higher 95% CIs 12.73 and 15.29).

CONCLUSIONS

Findings of this population-based study suggest that subclinical folate deficiency may represent a risk factor for the cognitive decline associated with aging that could contribute to AD as well as other dementia development.