Table 2. Correlations of T cell activation measures with cortisol measures^a.

Cortisol Measure	CD38 on CD8+ T cell MFI	CD38 on CD4+ T cell MFI
Waking cortisol	−0.17 (−0.35, 0.02), p = 0.08	−0.26 (−0.43, −0.08), p = 0.006
30 minute post-waking cortisol	−0.08 (−0.27, 0.11), p = 0.39	−0.20 (−0.37, −0.001), p = 0.049
Cortisol awakening responseb	0.10 (−0.10, 0.28), p = 0.32	0.11 (−0.09, 0.29), p = 0.28
Bedtime cortisol	0.14 (−0.05, 0.32), p = 0.14	0.07 (−0.12, 0.25), p = 0.50
Cortisol slopec	0.24 (0.04, 0.41), p = 0.017	0.24 (0.04, 0.41), p = 0.018

^aThe values shown are pairwise Pearson correlation coefficients between cortisol measures ((log₁₀ nmol/L) and cluster of differentiation (CD) 38 expression on T lymphocytes, measured as mean florescent intensity (MFI), with 95 percent confidence intervals in parentheses, followed by P-values for the corresponding correlation coefficients. The N used to calculate the coefficients is 101–109.

^bCortisol awakening response was calculated by subtracting waking cortisol from 30 minute post-waking cortisol, and was typically positive.

^cCortisol slope was calculated by subtracting waking cortisol from bedtime cortisol, and was typically negative.