Table 5.

Stress biomarkers before and after mental stress

	First month visit 1		Follow-up visit 2
Variable	Rest	Mental stress	Rest	Mental stress
Serum cortisol (mcg/dl)	7.01 ± 1.66	8.36 ± 2.46	7.0 ± 1.80	6.53 ± 1.96
Salivary cortisol (ng/dl)	76.7 ± 31.9	99.4± 63.5	84.3 ± 34.5	62.8 ± 28.8
Serum Epi (pg/ml)	13.7 ± 9.4	25.4 ± 16.1	17.3 ± 11.7	27.8 ± 12.3
Serum NE (pg/ml)	155.4 ± 53.0	203.7 ± 58.9	171.2 ± 52.4	212.1 ± 62.5
Serum IL-6 (pg/ml)	0.81 ± 0.69	0.83 ± 0.69	0.84 ± 0.71	0.85 ± 0.70

Data are presented as mean ± SD. Epi, epinephrine; NE, norepinephrine; IL-6, interleukin-6. Due to the counter-intuitive nature of cortisol decreasing in response to mental stress during visit 2, a linear regression analysis was highly significant for serum vs. salivary cortisol in all four conditions (rest, mental stress, visit 1, visit 2) as described in the text.