TY - JOUR
T1 - Zinc in Alzheimer's disease
T2 - A meta-analysis of serum, plasma, and cerebrospinal fluid studies
AU - Ventriglia, Mariacarla
AU - Brewer, George J.
AU - Simonelli, Ilaria
AU - Mariani, Stefania
AU - Siotto, Mariacristina
AU - Bucossi, Serena
AU - Squitti, Rosanna
PY - 2015/5/7
Y1 - 2015/5/7
N2 - To evaluate whether zinc levels in serum, plasma, and cerebrospinal fluid are altered in Alzheimer's disease (AD), we performed meta-analyses of 27 studies on the topic published from 1983 to 2014. The subjects' sample obtained by merging studies was a pooled total of 777 AD subjects and 1,728 controls for serum zinc studies, 287 AD subjects and 166 controls for plasma zinc, and of 292 AD subjects and 179 controls for CSF zinc. The main result of this meta-analysis is the very high heterogeneity among the studies either in demographic terms or in methodological approaches. Although we considered these effects in our analyses, the heterogeneity persisted and it has to be taken into account in the interpretation of the results. Our meta-analysis indicated that serum zinc appears significantly decreased in AD patients compared with healthy controls, and this result is confirmed when serum and plasma studies were analyzed together. If we considered the age-matched studies, the meta-analysis carried out on only six studies showed no significant difference in zinc levels between AD and healthy controls (SMD =-0.55, 95% CI (-1.18; 0.09); p = 0.094; I2 = 91%). In the light of these findings, we speculated about the possibility that the decreases observed could indicate a possible dietary zinc deficiency and we suggested that the possible involvement of zinc alterations in AD may have an interplay with copper metabolism.
AB - To evaluate whether zinc levels in serum, plasma, and cerebrospinal fluid are altered in Alzheimer's disease (AD), we performed meta-analyses of 27 studies on the topic published from 1983 to 2014. The subjects' sample obtained by merging studies was a pooled total of 777 AD subjects and 1,728 controls for serum zinc studies, 287 AD subjects and 166 controls for plasma zinc, and of 292 AD subjects and 179 controls for CSF zinc. The main result of this meta-analysis is the very high heterogeneity among the studies either in demographic terms or in methodological approaches. Although we considered these effects in our analyses, the heterogeneity persisted and it has to be taken into account in the interpretation of the results. Our meta-analysis indicated that serum zinc appears significantly decreased in AD patients compared with healthy controls, and this result is confirmed when serum and plasma studies were analyzed together. If we considered the age-matched studies, the meta-analysis carried out on only six studies showed no significant difference in zinc levels between AD and healthy controls (SMD =-0.55, 95% CI (-1.18; 0.09); p = 0.094; I2 = 91%). In the light of these findings, we speculated about the possibility that the decreases observed could indicate a possible dietary zinc deficiency and we suggested that the possible involvement of zinc alterations in AD may have an interplay with copper metabolism.
KW - Alzheimer's disease
KW - cerebrospinal fluid
KW - meta-analysis
KW - plasma
KW - serum
KW - zinc
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U2 - 10.3233/JAD-141296
DO - 10.3233/JAD-141296
M3 - Article
C2 - 25697706
AN - SCOPUS:84929379168
VL - 46
SP - 75
EP - 87
JO - Journal of Alzheimer's Disease
JF - Journal of Alzheimer's Disease
SN - 1387-2877
IS - 1
ER -