PT  - JOURNAL ARTICLE
AU  - Kenji Ishibashi
AU  - Airin Onishi
AU  - Yoshinori Fujiwara
AU  - Kiichi Ishiwata
AU  - Kenji Ishii
TI  - Relationship Between Alzheimer Disease–Like Pattern of <sup>18</sup>F-FDG and Fasting Plasma Glucose Levels in Cognitively Normal Volunteers
AID  - 10.2967/jnumed.114.150045
DP  - 2015 Feb 01
TA  - Journal of Nuclear Medicine
PG  - 229--233
VI  - 56
IP  - 2
4099  - http://jnm.snmjournals.org/content/56/2/229.short
4100  - http://jnm.snmjournals.org/content/56/2/229.full
SO  - J Nucl Med2015 Feb 01; 56
AB  - Increased plasma glucose (PG) levels can alter the cerebral distribution pattern of 18F-FDG uptake and reduce 18F-FDG uptake, especially in the precuneus. The 18F-FDG distribution pattern in cognitively normal subjects is described as an Alzheimer disease (AD)–like pattern. The aim of this study was to determine the fasting PG levels that can reduce 18F-FDG uptake in the precuneus. Methods: Fifty-one cognitively normal volunteers (mean age ± SD, 69.7 ± 5.9 y) underwent 18F-FDG PET scanning and were divided into 2 groups according to the level of fasting PG at the time of PET scanning: control (n = 31, 80 mg/dL ≤ fasting PG < 100 mg/dL) and impaired fasting glucose (IFG) (n = 20, 100 mg/dL ≤ fasting PG < 110 mg/dL). 18F-FDG uptake was compared between the 2 groups using voxelwise analyses with a global normalization method and volume-of-interest (VOI)–based analyses. VOIs were placed on the precuneus, posterior cingulate, and visual cortex, and the ratio of the uptake value on the precuneus VOI to that on the visual cortex VOI (PreCne/VC ratios) and to that on the posterior cingulate VOI (PreCne/PostCin ratios) was calculated. Results: Whole-brain voxelwise analyses showed that 18F-FDG uptake in the precuneus was significantly lower in the IFG group (P < 0.05, familywise error rate–corrected) than in the control group. VOI analyses showed significantly lower PreCne/VC ratios (P = 0.002) and PreCne/PostCin ratios (P = 0.004) in the IFG group than in the control group. Conclusion: The present study confirmed that increased fasting PG levels decrease 18F-FDG uptake, especially in the precuneus, as in the AD-like pattern. Furthermore, the study provided initial evidence that the AD-like pattern can appear even in an individual with a mildly higher level of fasting PG (100–110 mg/dL).