The Research Of The Relationship Between Serum 25-hydroxyvitamin D Level And Cognitive Impairment In The Eldly

Objective To examine the association between 25-hydroxyvitamin D(25-OH-D) and cognitive function in the eldly. Methods 299 cases of elderly patients who hospitalized in the Department of Gerontology of Shanghai Sixth People's Hospital from October 2010 to March 2011, were included.. They were 225 males and 74 females ,aging from 65 to 96 years old, mean age (80.03±5.71) years. Serum 25-OH-D concentrations were assayed with Electro-Chemiluminescence Immunoassay.Subjects were devided into group A, (<10ng/ml), group B, (10～19.99ng/ml) and group C(≥20ng/ml) according to the level of 25-OH-D. The cognitive function was tested with Mini Mental State Examination (MMSE), Montreal Cognitive Assessment(MoCA), Clinical Dementia Rating scale(CDR) and activities of daily living scale(ADL).Results Among 299 paticipants,the 25-OH-D concentration from 4.00 to 28.48 ng/ml ,mean was (12.04±6.35) ng/ml. There were 135 subjects (45.15%)in group A, 123 (41.13%)in group B and 41 (13.71%) in group C. Group A had lower MMSE score(26.02±3.99),MoCA score(21.56±5.59)vs group B (27.34±2.79,23.94±4.74) and group C (27.65±2.54,24.95±4.45).The difference was significant.The prevalence of cognitive dysfunction in group A (71.1%)was higher than that of in group B(55.3%) and group C(43.9%).The difference was also statistically significant.Spearman correlation analysis revealed that MMSE and MoCA were positively correlated to 25-OH-D(r=0.251,0.736,all P<0.01) .After adjustment for age,sex and education, MMSE and MoCA were also positively correlated to 25-OH-D(β=0.173, 0.243,all P <0.01).Stepwise regression analysis showed that MMSE and MoCA score relate to serum 25-OH-D levels,age and education.Conclusion There is generally low 25-OH-D level in the eldly and 25-OH-D is associated with cognitive function.Thoses with a serious lack of 25(OH)D (<10ng/ml) had lower MMSE and MoCA scores,and had a high risk of cognitive dysfunction.