Vitamin K Status Is not Associated with Cognitive Decline in Middle Aged Adults.
OBJECTIVE
The aim of this study was to examine the association between dephospho-uncarboxylated matrix Gla protein (dp-ucMGP), an indicator of vitamin K status, and cognitive decline, and the modifying role of 25(OH)D.


METHODS
Longitudinal study with six years follow-up.


METHODS
Community based.


METHODS
599 participants of the Longitudinal Aging Study Amsterdam (aged 55-65 years).


METHODS
Information processing speed and a composite Z-score by combining three domains of cognition reflecting general cognitive functioning.


RESULTS
Generalized estimating equations (GEE) showed no significant associations between dp-ucMGP and decline in general cognitive functioning. Vitamin D modified the association between dp-ucMGP and speed of information processing (p<0.05). In the group with a 25(OH)D concentration > 50 nmol/l, the highest tertile of dp-ucMGP (>406 pmol/l), which corresponds to lower vitamin K levels, was associated with 1.5 higher score on information processing speed (p=0.023) as compared to the lowest tertile of dp-ucMGP.


CONCLUSIONS
In contrast to our hypothesis, a suboptimal vitamin K was not associated with cognitive decline in middle-aged adults.
H.C. Comijs, GGZ in Geest/ Department of Psychiatry, A.J. Ernststraat 1187, 1081 HL Amsterdam, The Netherlands. Tel.: +31-20-7885699;fax: +31-20-4446775. E-mail address: h.comijs@ggzingeest.nl.
E G H M
EG
van den Heuvel
N M
NM
van Schoor
C
C
Vermeer
R M L
RM
Zwijsen
M
M
den Heijer
H C
HC
Comijs
D002135:Calcium-Binding Proteins / Q000097:blood*; D003071:Cognition; D003072:Cognition Disorders / Q000097:blood*; D016326:Extracellular Matrix Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014812:Vitamin K / Q000097:blood*; D014813:Vitamin K Deficiency / Q000150:complications / Q000523:psychology; D014815:Vitamins / Q000097:blood*; D000097568:Matrix Gla Protein
D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D014807:Vitamin D; D014812:Vitamin K; D014815:Vitamins; D000097568:Matrix Gla Protein; C104450:25-hydroxyvitamin D