Evaluation of endothelial function and cardiovascular risk in non-obese patients with slight degree of obstructive sleep apnea syndrome

Recently, it has been clearly described an independent relationship between obstructive sleep apnea syndrome (OSAS) and cardiovascular risk, with underlying mechanisms also including endothelial dysfunction. We enrolled 32 consecutive non-obese patients (mean age of 39.5 +/- 11.5 years), of which 16 with mild OSAS and 16 snoring without OSAS. Mild OSAS is defined by an AHI index between 5 and 15. We have investigated if whether there was a relationship between mild OSAS, endothelial function and carotid intima-media thickness (C-IMT). The population was divided into two groups: Group 1 (16 simple snorer patients with an average age of 39.4 +/- 12.1 years) and Group 2 (16 subjects with mild OSAS with an average age of 39.6 +/- 11.2 years). Each group underwent cardiovascular investigation including measurement of flow-mediated dilation (FMD) of the brachial artery and C-IMT. Both groups comprised non-obese subjects. Patients with mild OSAS had serum total cholesterol values statistically significantly higher than simple snores patients (178.6 +/- 24.9 vs 159.2 +/- 25.3; p=0.038). OSAS patients had also a trend towards higher values of maximum C-IMT compared to simple snorer patients (0.70 +/- 0.15 vs 0.65 +/- 0.16), although below the level of significance. Between the two groups, no difference was found for FMD values. The present results on mild OSAS strengthen the importance of a diagnosis of OSAS as soon as possible, in order to encourage all primary prevention interventions to correct risk factors responsible for disease progression and the occurrence of cardiovascular diseases, not excluding the use of therapies of non-invasive ventilation even in the early stages of the disease