Objective To investigate changes in resting glucose metabolism in the brain of patients with anemia of different degrees.

Methods The brain ¹⁸F-fluorodeoxyglucose (FDG) PET/CT imaging data of 51 patients who were clinically diagnosed with anemia in People's Hospital of Zhengzhou University from December 2016 to April 2019 were retrospectively analyzed. The study population included 16 males and 35 females aged 21−60 (41.13±9.78) years. According to the diagnostic criteria of anemia in WHO and relevant literature, the patients were divided into 3 groups: mild anemia (90 g/L–lower limits of normal), moderate anemia (60–90 g/L) and severe anemia (30−60 g/L). A total of 56 healthy physical examiners were recruited as controls; this group included 29 males and 27 females aged 19–58 (41.96±9.27) years. Statistical Parametric Mapping 8 software was used to process and analyze the PET images of anemia group and healthy controls. The brain PET images of all anemia groups and the control group were tested by voxel-to-voxel two-sample t-test to obtain difference distribution maps of brain PET metabolism between each group. XjView software was used to conduct stereotaxic and quantitative analyses of voxel values in brain regions reflecting statistical differences. The t values of all abnormal regions were obtained.

Results Compared with those in the control group, hypometabolic brain areas in patients with anemia were mainly distributed in the bilateral superior, middle, and inferior frontal gyri; the right inferior temporal gyri; and the right inferior parietal lobule gyri, the total voxel value was 3705 (t=5.01–5.85, all P<0.05). Hypermetabolic areas were not observed in anemia patients. Compared with that in the mild group, hypometabolism in the moderate group was observed in the bilateral inferior frontal, right middle frontal, right inferior temporal gyri, and the right inferior parietal lobule gyri, the total voxel value was 832 (t=5.22–5.86, all P<0.05). Hypometabolism in the severe group was observed in the bilateral superior frontal, bilateral middle-inferior frontal, right inferior temporal, and right inferior parietal lobule gyri, the total voxel value was 1834 (t=5.42–6.05, all P<0.05). Compared with that in the moderate group, hypometabolism in the severe group was noted in the left superior frontal, left middle-inferior frontal, and right middle frontal gyri, right inferior temporal lobe, and right inferior parietal lobule gyri, the total voxel value was 1598 (t=5.72–6.48, all P<0.05).

Conclusions Patients with anemia showed relative reductions in regional cerebral resting glucose metabolism. The cerebral regions demonstrating reduced metabolism were mainly related to emotion cognition. As anemia progressed, areas reflecting a decrease in cerebral metabolism increased.