Table 1.
Studies entered into the meta-analysis are listed based on the year of publication. VBM: voxel-based morphometry; fMRI: functional magnetic resonance imaging; Rs-fMRI: resting-state fMRI, FC: functional connectivity, ALFF: amplitude of low frequency fluctuation, GM: gray grey matter, WM: white matter, BDI: beck depression inventory.
| Author, year | Number of subjects (Insomnia/controls) | Number of males (Insomnia/controls) | Age of patients/controls (Mean ± SD) | Imaging modality | Covariates | |
|---|---|---|---|---|---|---|
| 1 | Son et al., 2017 [36] | 21/26 | 9/11 | 36.6 ± 9.8/33.2 ± 7.1 | t-fMRI | – |
| 2 | Kim et al., 2017 [39] | 14/18 | 4/4 | 49.0 ± 12.3/42.7 ± 12.3 | t-fMRI | Six motion parameters |
| 3 | Huang et al., 2017 [45] | 27/26 | 10/10 | 40.07 ± 11.62/41.19 ± 11.69 | rs-fMRI (whole-brain FC) |
Age and gender |
| 4 | Zhou et al., 2017 [41] | 27/27 | 17/17 | 42.59 ± 11.59/40.92 ± 11.46 | rs-fMRI (ALFF) | gender, age and the mean frame-wise displacement |
| 5 | Ran et al., 2017 [40] | 21/20 | 5/6 | 40.62 ± 7.52/38.65 ± 7.40 | rs-fMRI (ALFF) | Grey matter |
| 6 | Kay et al., 2016 [32] | 44/40 | 20/15 | 37/38 | PET | – |
| 7 | Li et al., 2016 [35] | 30/30 | 17/NS | 39.36 ± 8.53/36.15 ± 8.61 | t-fMRI | – |
| 8 | Li et al., 2016 [43] | 55/44 | 24/11 | 39.18 ± 10.34/39.91 ± 9.43 | rs-fMRI (ALFF) | sex, age and education level |
| 9 | Dai et al., 2016 [44] | 42/42 | 15/18 | 49.21 ± 10.96/49.14 ± 10.2 | rs-fMRI (ALFF) | age, sex, and years of education |
| 10 | Wang et al., 2015 [46] | 59/47 | 21/14 | 39.3 ± 10.7/40.0 ± 9.1 | rs-fMRI (ReHo) | head-motion measures |
| 11 | Dai et al., 2014 [42] | 24/24 | 7/12 | 54.8 ± 9.8/52.5 ± 6.6 | rs-fMRI (ReHo) | age, years of education, and/or sex |
| 12 | Baglioni et al., 2014 [34] | 22/38 | 7/17 | 40.7 ± 12.6/39.6 ± 8.9 | t-fMRI | six motion estimates, BDI scores |
| 13 | Chen et al., 2014 [47] | 17/17 | 0/0 | 27.16 ± 6.67/27.56 ± 6.83 | rs-fMRI (ICA) | – |
| 14 | Stoffers et al., 2014 [37] | 24/13 | 7/4 | 60.3 ± 6.0/60.1 ± 8.3 | t-fMRI | caudate region of interest baseline perfusion |
| 15 | Joo et al., 2014 [30] | 27/30 | 2/2 | 51.2 ± 9.6/50.4 ± 7.1 | Surface-based-analysis | BDI-II |
| 16 | Joo et al., 2013 [31] | 27/27 | 2/4 | 52.3 ± 7.8/51.7 ± 5.4 | VBM | age and sex and intracranial volume |
| 17 | Altena et al., 2010 [27] | 24/13 | 7/4 | 60.3 ± 6.0/60.2 ± 8.4 | VBM | Total GM or WM and age |
| 18 | Altena et al., 2008 [38] | 21/12 | 4/3 | 61 ± 6.2/60 ± 8.2 | t-fMRI | – |
| 19 | Nofzinger et al., 2004 [33] | 7/20 | 3/7 | 34.2 ± 8.9/32.6 ± 8.4 | PET | Global metabolism and age |