Table 1.

Cytokine Concentrations by Sleep Quality^a

Cytokine Concentration (pg/mL)	Good Sleepb (n = 7)	Poor Sleepc (n = 58)	Good Versus Poor Sleep Difference	Good Versus Poor Sleep P Value	Continuous Variable P Value
IL-6	37.6	34.2	−9%	.78	.48
TNF-α	0.8	1.2	+51%	.40	.72
IFN-γ	3.3	2.1	−37%	.25	.12
IL-Ira	6.8	3.1	−55%	.15	.06
IL-I-β	1.7	3.2	−86%	.28	.82
VEGF	664.0	934.0	+41%	.17	.04

NOTES: IL, interleukin; TNF, tumor necrosis factor; IFN, interferon; ra, receptor antagonist; VEGF, vascular endothelial growth factor; PSQI, Pittsburgh Sleep Quality Index.

^aLeast squares means adjusted for covariates as follows: IL-6: family history of colon cancer, how often person feels stress, prior stressful event.TNF-α: fruit juice intake per week. IFN-γ: family history of colon cancer, fruit juice intake per week. IL-Ira: body mass index, diarrhea in the past 6 months, fruit juice intake per week. IL-I-β: body mass index, circadian type.VEGF: use of nonsteroidal anti-inflammatory drugs, unable to visit doctor due to cost, packs of cigarettes smoked per day.

^bPSQI score <5.

^cPSQI score ≥5.