Increased levels of circulating ICAM-1, VCAM-1, and L-selectin in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) may be one of the most important ri sk factors of cardiovascular disorders, although the exact mechanism remain s to be elucidated. In the present study, we hypothesized that OSAS-induced hypoxic stress might be involved in the etiology of cardiovascular disorde rs by activating adhesion molecules, including intercellular adhesion molec ule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and L-selectin. To examine this hypothesis, we measured circulating ICAM-1, VCAM-1, and L- selectin levels before and after sleep in OSAS patients and age-matched con trols. The circulating ICAM-1, VCAM-1, and L-selectin levels increased in t he OSAS patients before sleep compared with the normal subjects (ICAM-1: 39 2.9 +/-: 48.5 vs. 201.2 +/- 55.0 ng/ml, P < 0.05; VCAM-1: 811.0 +/- 87.8 vs . 574.2 +/- 42.7 ng/ml, P < 0.05; L-selectin: 1,386.6 +/- 77.9 vs. 1,038.8 +/- 78.6 ng/ml, P < 0.01, respectively). After sleep, significantly greater levels of ICAM-1 and L-selectin, but not VCAM-1, were observed in the OSAS group. These observations suggest that OSAS-induced hypoxia activates adhe sion molecules, resulting in the important risk factor of cardiovascular di sorders. Treatment of OSAS can be, therefore, a potential approach to preve ntion of cardiovascular events.