Table 3.
Correlation analyses at baseline between serum IGF-I and MRI-estimated brain white matter volumes and neuropsychological test performance
| Baseline | ||
| SCI/MCI (n = 106) | AD (n = 59) | |
| Brain volumes (cm3) | ||
| Total white matter | rs = 0.26, p < 0.01 | rs = 0.20, p = 0.13 |
| Total corpus callosum | rs = 0.29, p < 0.01 | rs = 0.23, p = 0.09 |
| WMHs | rs = –0.08, p = 0.44 | rs = 0.18, p = 0.22 |
| Subsections of corpus callosum* | ||
| Anterior part | rs = 0.28, p < 0.01 | – |
| Central part | rs = 0.29, p < 0.01 | – |
| Posterior part | rs = 0.26, p < 0.01 | – |
| Global cognitive function | ||
| MMSE | rs = 0.15, p = 0.12 | rs = 0.01, p = 0.95 |
| Speed and executive function(response time in s) | ||
| TMT-A | rs = –0.22, p = 0.04 | rs = 0.20, p = 0.16 |
| TMT-B | rs = –0.10, p = 0.36 | rs = –0.14, p = 0.39 |
| Stroop Test I | rs = –0.13, p = 0.22 | rs = –0.04, p = 0.77 |
| Stroop Test II | rs = –0.28, p < 0.01 | rs = –0.03, p = 0.85 |
| Stroop Test III | rs = –0.21, p = 0.049 | rs = –0.14, p = 0.33 |
Correlations were calculated using the Spearman rank order correlation test. Rho values are presented as rs. Significant correlations are reported as bold text. *Subsections of corpus callosum were not evaluated in the AD group as there was no significant baseline correlation between IGF-I and total corpus callosum in AD. AD, Alzheimer’s disease; MMSE, Mini Mental State Examination; MRI, magnetic resonance imaging; SCI/MCI, subjective/objective mild cognitive impairment; TMT-A, trail making test A; TMT-B, trail making test B; WMH, white matter hyperintensity.