Is there a correlation between OSAS duration/severity and carotid intima-media thickness?

Obstructive Sleep Apnea Syndrome (OSAS) is a common airways disease recognized as an independent cardiovascular risk factor. It is often associated with obesity, diabetes and dyslipidemia. Its pathophysiological consequences (hypoxia, hypercapnia, micro-arousals, sympathetic hyperactivity, oxidative stress, systemic inflammation and hyper-coagulability) are implicated in the development of hypertension, endothelial dysfunction and higher intima-media thickness (IMT) values, all elements known to lead to atherosclerosis. The study aim was to demonstrate a relationship between OSAS duration and IMT values and to confirm how OSAS severity could influence IMT (a marker of atherosclerosis).

We enrolled 156 patients (125 men, mean age: 60 ± 12 years) affected by OSAS of different severity: 111 (71%) were in CPAP therapy; some of the population were also affected by hypertension [102 (65%)], dyslipidemia [52 (33%)] and diabetes [38 (24%)]. Patients underwent evaluation of carotid artery IMT and answered a questionnaire investigating the time of onset (confirmed by a person aware of the patient's previous sleeping habits) and the duration of the disease.

We found a statistically significant higher IMT value in patients with longer-lasting disease (OSAS duration in IMT < 0.9 mm: 120 (60-192) months versus OSAS duration in IMT ≥ 0.9 mm: 200 (120-310) months; p < 0.001). OSAS severity is positively related to IMT values. We found a positive relationship between IMT and OSAS duration [r = 0.34; p < 0.001] and between AHI and IMT [r = 0.51; p < 0.001].

Our study shows that the duration of OSAS and its severity are important factor related with higher values of IMT and hence with a higher risk of atherosclerosis.