Table 2. Age and biophysical parameters according to geographical region.
| Parameters | Guangzhou (n=92) | Nanjing (n=86) | Shijiazhuang (n=95) | Suwon (n=88) | p-value |
|---|---|---|---|---|---|
| Age (yr) | 28.9±9.1 | 29.1±9.5 | 28.4±9.4 | 30.4±9.5 | 0.516 |
| Temperature (oC) | |||||
| Cheek | 34.5±3.2 | 33.9±3.8 | 35.9±0.6 | 30.7±4.1 | 0.000*** |
| Forehead | 36.5±0.3 | 36.5±0.3 | 36.5±0.2 | 36.1±0.6 | 0.000*** |
| Hydration (AU) | |||||
| Cheek | 50.7±9.6 | 57.5±7.9 | 46.0±8.3 | 56.8±9.1 | 0.000*** |
| Forehead | 51.2±10.1 | 57.6±9.5 | 52.9±9.0 | 59.5±8.2 | 0.000*** |
| TEWL (g/m2) | |||||
| Cheek | 17.9±4.0 | 18.1±5.0 | 16.7±3.9 | 14.6±3.1 | 0.000*** |
| Forehead | 18.9±3.4 | 20.1±4.0 | 17.7±3.9 | 15.7±2.7 | 0.000*** |
| Sebum (μg/cm2) | |||||
| Cheek | 102.1±68.4 | 145.5±79.1 | 43.4±23.1 | 44.7±26.9 | 0.000*** |
| Forehead | 210.9±104.0 | 246.5±95.7 | 92.3±54.0 | 101.7±53.5 | 0.000*** |
| Elasticity (R2) | 0.6±0.1 | 0.5±0.2 | 0.6±0.1 | 0.6±0.1 | 0.140 |
| Pore size (%) | 40.6±9.1 | 40.1±10.4 | 43.8±10.2 | 42.0±10.6 | 0.060 |
| Wrinkle (%) | 10.5±6.5 | 12.6±7.6 | 15.0±11.1 | 8.3±5.1 | 0.000*** |
| Skin tone (%) | 57.3±2.9 | 59.0±3.1 | 57.9±3.1 | 59.7±2.8 | 0.000*** |
Values are presented as mean±standard deviation. AU: arbitrary units, TEWL: transepidermal water loss. ***p<0.001.