## 3 Results
### Association between Hypertension and Facial Characteristics  
The LASSO method was performed to select the facial characteristic variables that could be used as hypertension predictors. In this study, several facial characteristic variables were selected by LASSO analysis. In general, age and BMI were selected for both men and women. All facial characteristics variables selected by LASSO were shown in Tables 6 and 7. Illustrative figures of facial characteristics were shown in Figure 3. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Variable Descriptions**} & \multirow{2}{*}{**Variables**} & \multicolumn{3}{c}{**Women (_n = 723_)**} \\ \cline{3-6} \multicolumn{2}{c}{} & & **Normal (_n = 560_)** & **Hypertensive (_n = 163_)** & _p-Value_ \\ \hline \multirow{4}{*}{Frontal face} & Face contour angle & FAs\_153\_194 & 88.43 \(\pm\) 0.11 & 89.04 \(\pm\) 0.23 & 0.020 \\ \cline{2-6}  & & FD\_17\_26 & 9.27 \(\pm\) 0.06 & 8.81 \(\pm\) 0.11 & 0.001 \\  & & FD\_117\_126 & 9.36 \(\pm\) 0.06 & 9.02 \(\pm\) 0.12 & 0.011 \\  & Eye length and ratio & FDH\_17\_26\_18\_25 & 0.29 \(\pm\) 0.00 & 0.28 \(\pm\) 0.00 & 0.007 \\  & & FDD\_17\_26\_52\_81 & 0.21 \(\pm\) 0.00 & 0.20 \(\pm\) 0.00 & 0.003 \\  & & FDD\_17\_26\_52\_50 & 0.13 \(\pm\) 0.00 & 0.12 \(\pm\) 0.00 & 0.002 \\ \hline \multirow{4}{*}{Profile face} & Forehead shape & PAi\_71\_72 & 78.55 \(\pm\) 0.25 & 77.30 \(\pm\) 0.49 & 0.029 \\ \cline{2-6}  & \multirow{2}{*}{Nose length and area} & PDH\_14\_21 & 13.29 \(\pm\) 0.07 & 12.96 \(\pm\) 0.13 & 0.026 \\  & & PA\_14\_21 & 45.92 \(\pm\) 0.19 & 47.12 \(\pm\) 0.38 & 0.007 \\  & & PA\_12\_14\_21 & 107.81 \(\pm\) 0.22 & 109.02 \(\pm\) 0.43 & 0.017 \\ \hline \multirow{4}{*}{Facial color} & \multirow{4}{*}{Forehead color} & FhR\_L & 69.97 \(\pm\) 0.24 & 68.62 \(\pm\) 0.47 & 0.015 \\  & & FhR\_a & 10.24 \(\pm\) 0.11 & 10.77 \(\pm\) 0.21 & 0.030 \\  & & FhL\_a & 10.07 \(\pm\) 0.10 & 10.74 \(\pm\) 0.21 & 0.006 \\  & & FhW\_a & 10.15 \(\pm\) 0.10 & 10.76 \(\pm\) 0.20 & 0.009 \\ \cline{2-6}  & \multirow{2}{*}{Cheek color} & ChRU\_L & 65.07 \(\pm\) 0.21 & 63.49 \(\pm\) 0.42 & 0.002 \\  & & ChRW\_L & 61.61 \(\pm\) 0.22 & 60.21 \(\pm\) 0.43 & 0.005 \\ \cline{2-6}  & \multirow{2}{*}{Nose color} & Nose\_L & 70.22 \(\pm\) 0.24 & 68.85 \(\pm\) 0.48 & 0.016 \\  & & Nose\_a & 11.87 \(\pm\) 0.11 & 12.55 \(\pm\) 0.22 & 0.009 \\ \hline \hline \end{tabular} Data are represented as adjusted mean \(\pm\) SE (standard error). _p-_values were calculated using ANCOVA with a significant level of _p \(<\)_ 0.05.  
\end{table} 
Table 5: Differences in facial characteristic variables in women. Figure 2: Illustrative figures of facial characteristics for both genders. \begin{table}
\begin{tabular}{c c} \hline \hline
**Variable Descriptions** & **Selected Variables** \\ \hline \hline \multirow{7}{*}{Frontal face} & BMI \\  & AGE \\ \hline \multirow{7}{*}{Facial width, ratio, and angle} & FD\_53\_153 \\  & FVD\_52\_81\_53\_153 \\  & FA\_117\_125\_143 \\  & FA\_18\_94\_50 \\ \hline \multirow{7}{*}{Frontal face} & FD\_117\_126 \\  & Eye length, ratio, and angle \\ \cline{2-2}  & FHD\_118\_118\_53\_153 \\  & FHD\_25\_125\_53\_153 \\  & FAis\_125\_117 \\ \hline \multirow{7}{*}{Profile face} & Mouth ratio \\ \cline{2-2}  & Forehead shape \\ \cline{2-2}  & Nose horizontal distance and tilting angle \\ \cline{2-2}  & Forehead color \\ \cline{2-2}  & FHR\_a \\ \cline{2-2}  & Cheek color \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Variables selected using a model based on LASSO in men.