## 3 Results
### Partial Correlation Analysis  
The results of the partial correlation analysis are summarized in Table 2 and Figure 2. There were significant correlations between GM-BHQ and SBP (\(r=-0.10\), \(p=0.001\)), BMI (\(r=-0.19\), \(p<0.001\)), body fat percentage (\(r=-0.13\), \(p<0.001\)), AST (\(r=-0.11\), \(p<0.001\)), ALT (\(r=-0.12\), \(p<0.001\)), \(\gamma\)-GTP (\(r=-0.13\), \(p<0.001\)), Glu (\(r=-0.12\), \(p<0.001\)), and Alc (\(r=-0.09\), \(p<0.001\)).  
Since the age range of the participants is large, we performed the same analysis for younger and older participants than the median as ad-hoc analyses (Supplementary Material). The numbers of the younger group (less than or equal to 64 years old) and older group (over 64 years old) were 891 and 908, respectively. BMI and \(\gamma\)-GTP showed significance for  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Mean \(\pm\) Standard Deviation (Range)** & **Partial Correlation** & \(p\) \\ \hline
**Blood pressure** & & & \\ systolic blood pressure & \(126.6\pm 16.8\) (87–206) mmHg & \(-0.10\) & 0.001 \({}^{*}\) \\ diastolic blood pressure & \(73.4\pm 10.9\) (45–128) mmHg & \(-0.06\) & 0.03 \\ heart rate & \(63.1\pm 10.5\) (37–117) ppm & \(-0.09\) & 0.004 \\
**Obesity measurements** & & & \\ body mass index & \(22.9\pm 3.2\) (14.2–48.4) & \(-0.19\) & \(<\)0.001 \({}^{*}\) \\ waist circumference & \(82.6\pm 9.2\) (55.5–127.6) cm & \(-0.07\) & 0.009 \\ body fat percentage & \(24.5\pm 6.4\) (7.0–48.5) \% & \(-0.13\) & \(<\)0.001 \({}^{*}\) \\
**Liver function** & & & \\ total protein & \(7.4\pm 0.4\) (6.2–10.1) g/dL & 0.00 & 0.921 \\ albumin & \(4.4\pm 0.2\) (3.4–5.5) g/dL & 0.01 & 0.758 \\ total bilirubin & \(0.8\pm 0.3\) (0.2–3.5) mg/dL & 0.01 & 0.672 \\aspartate aminotransferase & & & \\ (AST) & & & \\ alanine aminotransferase & & & \\ (ALT) & & & \\ \(\gamma\)-glutamyltransferase & & & \\ (\(\gamma\)-GTP) & & & \\
**Renal function** & & & \\ blood urea nitrogen (BUN) & \(15.1\pm 4.0\) (5.6–55.1) mg/dL & 0.00 & 0.984 \\ creatinine (Cr) & \(0.8\pm 0.3\) (0.4–8.7) mg/dL & \(-0.01\) & 0.559 \\ uric acid & \(5.3\pm 1.3\) (0.7–11.1) mg/dL & \(-0.07\) & 0.003 \\
**Lipid metabolism** & & & \\ total cholesterol & \(211.0\pm 54.3\) (24–2013) mg/dL & 0.07 & 0.05 \\ triglyceride cholesterol & \(109.9\pm 69.8\) (28–924) mg/dL & \(-0.12\) & 0.744 \\ high-density lipoprotein & & & \\ (HDL) & \(64.4\pm 16.4\) (30–155) mg/dL & \(-0.02\) & 0.587 \\ low-density lipoprotein (LDL) & \(120.0\pm 30.3\) (15–236) mg/dL & 0.05 & 0.147 \\
**Electrolytes** & & & \\ Na & \(141.0\pm 1.8\) (131–146) mEq/L & 0.02 & 0.644 \\ K & \(4.1\pm 0.3\) (2.6–5.3) mEq/L & \(-0.03\) & 0.45 \\ Cl & \(102.7\pm 2.4\) (95–111) mEq/L & 0.00 & 0.979 \\ Ca & \(9.4\pm 0.3\) (7.6–11.0) mEq/L & 0.00 & 0.903 \\
**Glycometabolism** & & & \\ fasting blood glucose (Glu) & \(102.2\pm 19.3\) (72–334) mg/dL & \(-0.12\) & \(<\)0.001 \({}^{*}\) \\ haemoglobin A1c (HbA1c) & \(5.6\pm 0.6\) (3.7–10.9) \% & \(-0.09\) & \(<\)0.001 \({}^{*}\) \\
**Blood cell values** & & & \\ white blood cell count (WBC) & \(54.8\pm 14.6\) (18.4–169.3) \(\times\)\(10^{2}\)/mL & 0.01 & 0.792 \\ red blood cell count (RBC) & \(460.5\pm 43.9\) (241–600) \(\times\)\(10^{4}\)/mL & \(-0.01\) & 0.688 \\ haemoglobin (Hb) & \(14.4\pm 1.4\) (7.7–19.0) g/dL & \(-0.05\) & 0.061 \\ haematocrit (Ht) & \(42.3\pm 3.8\) (24–55) \% & \(-0.08\) & 0.005 \\ platelet count (PLT) & \(22.6\pm 6.1\) (5–169) \(\times\)\(10^{4}\)/mL & 0.01 & 0.657 \\ fibrinogen & \(288.0\pm 63.7\) (140–630) mg/dL & 0.06 & 0.056 \\ \hline \hline \end{tabular} \({}^{*}\)Statistical significance with Bonferroni correction for multiple comparisons.  
\end{table}
Table 2: Correlations between grey matter brain healthcare quotient and blood data, blood pressure, and obesity measurements.  
both the younger and older group. Waist circumference, body fat percentage, ALT, and Glu showed significance only for the younger group.