Table 1.
Participants’ Characteristics and Neuroimaging Markers of Interest at the Time of Brain MRI and Their Bivariate Associations With the Slope of Energy and Mild Parkinsonian Signs (n = 293)
| Mean (SD) Are Reported Unless Otherwise Noted | Correlations With SEL Slopes, r (p value) or Mean Difference ± SD (p value) | Correlations With MPS, Mean Difference ± SD (p value), Chi square or t Test p-value, or r (p Value) | |
|---|---|---|---|
| Demographics | |||
| Age, y | 83.0 (2.8) | −0.029 (.620) | 1.2 ± 2.8 (<.001) |
| Women, N (%) | 171 (58) | −0.006 ± 0.05 (.318) | 0.999 |
| Black, N (%) | 114 (39) | 0.010 ± 0.05 (.069) | 0.630 |
| Postsecondary education | 151 (52) | −0.002 ± 0.05 (.684) | 0.195 |
| Body mass index, kg/m2 | 27.4 (4.4) | −0.090 (.124) | 0.6 ± 4.4 (.280) |
| Energy | |||
| Baseline SEL at Year 2 | 6.8 (1.5) | 0.049 (.399) | −0.2 ± 1.5 (.260) |
| SEL slopes, change per year | −0.06 (0.05) | — | −0.019 ± 0.049 (.001) |
| Mobility performance at Year 1 | |||
| Short Physical Performance Battery (0–12) | 10.4 (1.3) | 0.224 (<.001) | −0.48 ± 1.23 (.001) |
| Chair stand per second | 0.39 (0.11) | 0.194 (<.001) | −0.05 ± 0.11 (<.001) |
| Gait speed over 3, 4, or 6 m, m/s | 1.27 (0.24) | 0.118 (.043) | −0.07 ± 0.24 (.012) |
| Standing balance, s (0–90) | 72.9 (20.8) | 0.119 (.042) | −6.6 ± 20.6 (.008) |
| Mild parkinsonian signs (UPDRS ≥ 1), N (%) | 128 (44) | −0.019 ± 0.049 (.001) | |
| Fatigue, N (%) | 85 (29) | −0.030 ± 0.048 (<.001) | 0.027 |
| Prevalence of cardiovascular disease | 84 (29) | −0.005 ± 0.050 (.405) | 0.364 |
| Prevalence of stroke | 24 (8) | −0.005 ± 0.050 (.648) | 0.391 |
| Prevalence of diabetes | 74 (25) | −0.017 ± 0.050 (.014) | 0.685 |
| Prevalence of myocardial infarction | 49 (17) | −0.011 ± 0.050 (.164) | 0.999 |
| Normalized white matter hyperintensities | 0.0058 (0.0074) | −0.018 (.760) | 0.002 ± 0.007 (.007) |
| Striatum, cm3 | 11.6 (3.7) | 0.112 (.056) | −0.005 (.927) |
| Left striatum | 5.5 (2.0) | 0.073 (.217) | −0.015 (.800) |
| Right striatum | 6.1 (1.9) | 0.140 (.017) | 0.005 (.937) |
| Globus pallidus, cm3 | 0.53 (0.49) | 0.040 (.498) | 0.018 (.757) |
| Left pallidus | 0.25 (0.24) | 0.024 (.680) | 0.007 (.902) |
| Right pallidus | 0.29 (0.28) | 0.049 (.401) | 0.026 (.660) |
| Thalamus, cm3 | 1.8 (0.4) | −0.046 (.438) | −0.002 (.970) |
| Left thalamus | 0.91 (0.23) | −0.052 (.380) | −0.026 (.657) |
| Right thalamus | 0.93 (0.24) | −0.035 (.555) | 0.021 (.727) |
| Primary motor cortex, cm3 | 16.8 (2.7) | 0.054 (.357) | −0.183 (.002) |
| Left precentral gyrus | 8.8 (1.5) | 0.002 (.974) | −0.165 (.005) |
| Right precentral gyrus | 8.1 (1.4) | 0.099 (.090) | −0.169 (.004) |
| Primary sensory cortex, cm3 | 19.1 (3.2) | 0.084 (.150) | −0.161 (.006) |
| Left postcentral gyrus | 10.0 (1.8) | 0.080 (.171) | −0.151 (.010) |
| Right postcentral gyrus | 9.1 (1.7) | 0.074 (.203) | −0.145 (.013) |
| Limbic area, cm3 | 29.3 (3.9) | −0.009 (.877) | −0.065 (.265) |
| Left limbic area | 14.5 (2.1) | 0.016 (.783) | −0.055 (.347) |
| Right limbic area | 14.8 (2.0) | −0.034 (.568) | −0.068 (.245) |
| Dorsolateral prefrontal cortex, cm3 | 2.7 (3.2) | 0.012 (.832) | −0.123 (.036) |
| Left middle frontal gyrus | 13.2 (1.7) | 0.013 (.823) | −0.114 (.053) |
| Right middle frontal gyrus | 13.8 (1.8) | 0.009 (.873) | −0.108 (.066) |
Notes: MPS = mild parkinsonian signs; SEL = self-reported energy level; UPDRS = Unified Parkinson Disease Rating Scale. Correlations with regional neuroimaging markers were adjusted for normalized total gray matter volume, ie, ratio of total gray matter volume by intracranial volume. The bold number reflects correlations at p <.05. Normalized white matter hyperintensities: ratio of total white matter hyperintensities by total brain volume.