Table 5.
Single Linear Regression Model between Different Biological and Psychological Variables and Cortisol Levels using Hair and Earwax Samples.
| Sample Variable | Right-ECCδ (pg/mg) |
Left-ECCφ (pg/mg) |
HCCδ (pg/mg) |
SCCφ (pg/ml) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| β | p-value | CI | β | p-value | CI | β | p-value | CI | β | p-value | CI | |
| Age | 0.6 | 0.78 | -3.8; 6.2 |
-4.0 | 0.21 | -10.3; 2.3 |
0.1 | 0.48 | -0.1; 0.2 |
-43.9 | 0.14 | -103.5; 15.4 |
| Sex | 53.8 | 0.14 | -19.0; 126.7 |
72.8 | 0.25 | -53.2; 198.9 |
3.7 | <0.01∗ | 1.1; 6.3 |
593.8 | 0.42 | -780.5; 1858.1 |
| Alcohol (unit) ▽ | -2.3 | 0.73 | -16.0; 11.4 |
-12.5 | 0.03∗ | -23.0; -1.9 |
0.1 | 0.60 | -0.4; 0.6 |
197.3 | 0.22 | -122.8; 517.5 |
| Tobacco usage (yes) | -26.0 | 0.54 | -112.5; 60.8 |
43.9 | 0.60 | -119.5; 207.2 |
3.0 | 0.06 | -0.2; 6.3 |
1800.7 | 0.01∗ | 317.8; 3283.6 |
| BMI (Kg/cm2) | 4.3 | 0.37 | -5.4; 14.0 |
0.83 | 0.92 | -17.37; 19.1 |
0.3 | 0.12 | -0.1; 0.7 |
-24.6 | 0.78 | -207.8; 157.9 |
| Waist circumference (cm) | 0.8 | 0.53 | -1.8; 3.4 |
1.5 | 0.60 | -4.0; 6.9 |
0.1 | 0.17 | <-0.1, 0.2 |
-20.6 | 0.36 | -65.2; 24.0 |
| Anti-conceptive pill | -8.6 | 0.82 | -87.8; 70.6 |
-154.0 | 0.01∗ | -274.8; -33.2 |
<0.1 | 0.98 | -2.8; 2.9 |
259.9 | 0.42 | -371.6; 891.4 |
| Hair washing frequency | 15.1 | 0.19 | -7.9; 38.1 |
-0.6 | 0.97 | -36.1; 35.0 |
0.6 | 0.15 | -0.2; 1.5 |
235.7 | 0.21 | -135.7; 607.2 |
| Cosmetic treatment | 81.4 | 0.47 | 147.9; 310.7 |
-155.8 | 0.02∗ | -286.4; -25.2 |
-6.3 | 0.87 | -8.8; 7.5 |
-24.5 | 0.99 | -4303.5; 4254.5 |
| PSS | -1.0 | 0.72 | -6.9; 4.8 |
-2.3 | 0.59 | -10.8; 6.2 |
<-0.1 | 0.98 | -0.3; 0.2 |
-8.3 | 0.88 | -121.5; 105.1 |
| Number of Hassles | -0.2 | 0.91 | -3.8; 3.4 |
-3.8 | 0.21 | -9.9; 2.2 |
<-0.1 | 0.60 | -0.2; 0.1 |
-0.1 | 0.99 | -69.9; 69.7 |
| Severity of Hassles | -0.6 | 0.58 | -2.7; 1.6 |
-1.9 | 0.17 | -4.8; 0.8 |
<-0.1 | 0.78 | -0.1; 0.1 |
-3.04 | 0.88 | -44.3; 38.3 |
| RLCQ | -0.1 | 0.51 | -0.4; 0.2 |
<0.1 | 0.94 | -0.6; 0.7 |
<-0.1 | 0.88 | <-0.1; <0.1 |
2.9 | 0.37 | -3.6; 9.4 |
| Severe RLCQ |
-17.5 | 0.43 | -62.7; 27.6 |
0.9 | 0.98 | -81.0; 82.9 |
<-0.1 | 0.96 | -1.7; 1.7 |
587.7 | 0.11 | -126.8; 1302.2 |
PSS: Perceived Stress Scale. RLCQ: Recent Life Event Questionnaire. ▽: One alcohol unit is measured as 10ml or 8g of pure alcohol. This equals one 25ml single measure of whisky (Alcohol by volume [ABV] 40%), or a third of a pint of beer (ABV 5–6%) or half a standard (175ml) glass of red wine (ABV 12%). ∗: p<0.05 was significant. δ: p value was calculated using Linear Regression Models. φ: p-value was calculated using Generalized Linear Models (GLMs) Right−ECC was obtained using an earwax self-sampling device and Left−ECC was using a clinical syringing method (The Reiner−Alexander syringe).