OBJECTIVE: This study aimed to examine the association between normal-but-low folate levels and cognitive function in the elderly population using a prospective cohort study. METHODS: We analyzed 3,910 participants whose serum folate levels were within the normal reference range (1.5–16.9 ng/mL) at baseline evaluation in the population-based prospective cohort study named the “Korean Longitudinal Study on Cognitive Aging and Dementia.” The association between baseline folate quartile categories and baseline cognitive disorders [mild cognitive impairment (MCI) or dementia] was examined using binary logistic regression analysis adjusting for confounding variables. The risks of incident MCI and dementia associated with the decline of serum folate level during a 4-year follow-up period were examined using multinomial logistic regression analysis. RESULTS: The lowest quartile group of serum folate (≥1.5, ≤5.9 ng/mL) showed a higher risk of cognitive disorders than did the highest quartile group at baseline evaluation (odds ratio 1.314, p=0.012). Over the 4 years of follow-up, the risk of incident dementia was 2.364 times higher among subjects whose serum folate levels declined from the 2nd–4th quartile group to the 1st quartile than among those for whom it did not (p=0.031). CONCLUSION: Normal-but-low serum folate levels were associated with the risk of cognitive disorders in the elderly population, and a decline to normal-but-low serum folate levels was associated with incident dementia. Maintaining serum folate concentration above 5.9 ng/mL may be beneficial for cognitive status.
Aged ; Cognition ; Cognition Disorders ; Cognitive Aging ; Cohort Studies ; Confounding Factors (Epidemiology) ; Dementia ; Folic Acid ; Follow-Up Studies ; Humans ; Logistic Models ; Longitudinal Studies ; Prospective Studies ; Reference Values

We analyzed the direct medical costs for Korean patients with type 2 diabetes according to the type of complications and the number of microvascular complications. We analyzed costs for type 2 diabetes and associated complications in 3,125 patients. These data were obtained from the Korean National Diabetes Program (KNDP), a large, ongoing, prospective cohort study that began in 2005. The cost data were prospectively collected, using an electronic database, for the KNDP cohort at six hospitals. The costs were analyzed according to complications for 1 yr from enrollment in the study. Among 3,125 patients, 918 patients had no vascular complications; 1,883 had microvascular complications only; 51 had macrovascular complications only; and 273 had both complications. The annual direct medical costs for a patient with only macrovascular, only microvascular, or both macrovascular and microvascular complications were 2.7, 1.5, and 2.0 times higher than the medical costs of patients without complications. Annual direct medical costs per patient increased with the number of microvascular complications in patients without macrovascular complications. The economic costs for type 2 diabetes are attributable largely to the management of microvascular and macrovascular complications. Proper management of diabetes and prevention of related complications are important for reducing medical costs.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Cohort Studies ; Costs and Cost Analysis ; Databases, Factual ; Diabetes Mellitus, Type 2/complications/*economics ; Female ; Health Care Costs ; Humans ; Male ; Middle Aged ; Prospective Studies ; Republic of Korea ; Vascular Diseases/complications ; Young Adult