A total of 114 patients with ED were prospectively enrolled, with 63 (55.3%) of them belonging to the vascular ED group with a median age of 36 years (age range, 21–62 years), and 51 (44.7%) of them belonging to the non-vascular ED group with a median age of 32 years (age range, 23–48 years). Continuous data in this study were not normally distributed. There was no significant difference in age between the two groups (P > 0.05, Table 1).
Table1: Age and SWE values in vascular ED and non-vascular ED groups:
|
Total
(n= 114)
|
Vascular ED(n = 54)
|
Non-vascular ED
(n = 60)
|
P value
|
Age (y) Min–max (median)
SWE value (m/s)
|
21–62 (35)
|
21–62 (36)
|
23–56(33.5)
|
0.281a
|
Flaccid state (Mean ±SD)
|
2.37±0.32
|
2.44±0.32
|
2.32±0.32
|
0.040a
|
Erectile state (Mean ±SD)
|
1.06±0.36
|
1.16±0.36
|
0.97±0.34
|
<0.001a
|
P value
|
<0.001b
|
<0.001b
|
<0.001b
|
|
a comparison of SWE in vascular ED and non-vascular ED groups
a comparison of SWE in a flaccid state and an erectile state
Correlation between SWE value of CCP and age of patients:
First, we investigated the relationship between the SWE value of CCP and age in different groups. As shown in Fig. 1, age was negatively associated with the SWE value of CCP before ICI in the group with vascular ED (r = -0.288, P = 0.035, P < 0.05). However, there was no significant correlation between the SWE value of CCP before ICI and the age of patients in the non-vascular ED group (r = 0.045, P = 0.732). As shown in Fig. 2, there is no significant correlation between the SWE value of CCP after ICI and age in either the vascular ED or non-vascular ED group (r = -0.052, P = 0.708; r = 0.007, P = 0.960, respectively).
SWE value of CCP in different Group:
Three cases showed that the SWE of values non-vascular ED and vascular ED (arterial ED and venogenic ED), in m/s (Fig. 3). As shown in Table 1, the SWE value of CCP before ICI was significantly higher than the SWE value of CCP after ICI (P < 0.001) for all patients. Similarly, there was a significant difference between the SWE value of CCP before ICI and the SWE value of CCP after ICI in both the vascular ED and non-vascular ED groups (P < 0.001).
In an erectile state, the SWE value of vascular ED was significantly greater than that of non-vascular ED (P < 0.001). Similarly, significant differences in SWE values of CCP were found between the vascular ED and non-vascular ED groups in a flaccid state (Table 1, P = 0.040; P < 0.05).
Application of SWE value in predicting vascular erectile dysfunction:
Based on the statistically significant difference, we considered calculating a cut-off value for SWE values of CCP in flaccid and erectile states separately. ROC analysis showed that at the SWE cut-off value of 2.32 m/s in a flaccid state, the sensitivity, specificity, PPV, and NPV for predicting the vascular ED were 68.52%, 51.67%, 56.06%, and 64.28%, respectively (shown in Fig. 4a); the AUC was 0.612. The ROC analysis revealed that at the SWE cut-off value of 0.88 m/s in an erectile state, the sensitivity, specificity, PPV, and NPV for predicting vascular ED were 77.78%, 60.00%, 63.64%, and 75.00%, respectively; the AUC was 0.700 (shown in Fig. 4b).