Chronic oxidative stress and increased inflammation are responsible for the formation of many chronic diseases (Dyugovskaya et al. 2002; Cakmak et al. 2009). Treatments given to reduce long-term complications in OSAS patients are required to reduce oxidative stress and inflammation. For this, it is necessary to evaluate the initial oxidative stress and inflammation levels of the patients and their changes with the treatment given (Dyugovskaya et al. 2002; Cakmak et al. 2009). In this study, it was found that inflammation and oxidative stress did not correlate with the level of systemic biomarkers (mild, moderate or severe) at the onset of the disease treatment in OSAS patients, there was no change in systemic biomarkers with surgical treatment and a significant increase in HDL levels.
In this study, the change of CRP and leukocyte counts as inflammatory markers was evaluated
Freire et al. examined the leukocyte count retrospectively in 119 patients diagnosed with OSAS, and no relationship was found between OSAS and leukocyte count (Freire et al. 2010). In this study, there was no difference between the groups in preoperative leukocyte values. Postoperative 3rd day measurement was found to be significantly higher in all groups compared to other measurements. This may be due to the continuation of the surgical effect in the early postoperative period.
Tillet and Francis firstly defined CRP showing precipitation with pneumococcal C polysaccharides in the serum of patients with pneumonia as an acute phase reactant (Tillett and Francis Jr. 1930). It is synthesized from liver cells in response to tissue damage, infection, and inflammation (Whitehead et al. 1983; Castell et al. 1990). Yokoe et al. 2003 found that the CRP levels in patients with OSAS (n: 30) were significantly higher than the obese control group (n: 14), and a relationship was found between OSAS grade and CRP level. In a study conducted by Shamsuzzaman et al. 2002, CRP levels were found to be significantly higher in patients with OSAS (n: 22) compared to the healthy control group (n: 20), and it was observed that the CRP level was associated with the degree of OSAS. In this study, no difference was found between the groups with and without OSAS in terms of CRP. In Yokoe et al., unlike ours, the control group was selected from extremely obese individuals, only male patients were included in the study, the OSAS patient group was not classified within itself, and the number of patients was less than our study. In the Shamsuzzaman et al. study, the number of patients was less than the number of our patients, and the patients were selected from patients who had no additional systemic disease and had no OSAS treatment. The different results may be due to these reasons. In the study, CRP was found to be significantly higher in the third measurement than other measurements. This may be due to the continuing inflammatory effect of the operation in the early postoperative period.
In the study, PON, ARE, and NT changes were evaluated as oxidative stress markers
An increase has been reported in the systemic biological indicators of inflammation and oxidative stress in patients with OSAS (Cofta et al. 2008). Barcello et al. reported increased systemic oxidative stress in patients with severe OSAS (Barceló et al. 2006). Reduced antioxidant enzyme activity indicates the presence of systemic oxidative stress in patients with OSAS (Barceló et al. 2006; Christou et al. 2003). Impaired antioxidant defense may exacerbate the deleterious effects of oxidative stress on the vascular endothelium in patients with OSAS (Barcelo et al. 2000).
PON1 and ARE are enzymes in the esterase group, which are encoded by the same gene and whose active centers are similar. PON1 enzyme has an antioxidant function due to its ability to protect LDL from oxidation and to neutralize other radicals, including hydrogen peroxide. ARE is accepted as the indicator of the main protein that is not affected by changes in PON (Li et al. 1993; Ozdin 2002). More than 80% of PON1 circulates depending on HDL (Aviram and Vaya 2013; Deakin et al. 2005). PON1 and ARE are proteins that control oxidative stress (Mackness et al. 1998). PON and ARE activities decrease in chronic inflammatory diseases (Dyugovskaya et al. 2002; Cakmak et al. 2009). Lavie et al. 2004, in his study on 114 patients with OSAS and 30 without OSAS, showed decreased plasma PON1 activity. Baysal et al. (2008) found that PON and ARE activities were lower in OSAS patients compared to the control group (p < 0.005).
Unlike ours, Baysal et al. patients with any systemic disease were not included in the study. In the study conducted by Lavie et al., patients with OSAS were divided into patients with and without cardiovascular disease and compared with patients without OSAS. In both studies, patients with OSAS were not grouped according to their severity, as in our study.
NT is formed by the interaction of peroxynitrite and the tyrosine residues of the proteins and may be used as an indicator of potential cytotoxic effects of NO (Alonso et al. 2002). Jelic et al. 2010 reported a correlation between the severity of AHI and NT expression, which was reduced in patients who had received CPAP for more than 4 h daily. Svatikova et al. 2004 measured the plasma levels of NT at 21.00, prior to sleep, at 06.00 and after waking up, in patients with OSAS. The free NT levels at the baseline were found to be similar prior to sleep between the control and the OSAS groups. No significant difference was observed in plasma NT levels in normal sleep or apneic sleep. The reason for this difference is as follows: in the study conducted by Jelic et al. 2010, volunteers were selected from the community through advertising, and these people were given polysomnography, and those with systemic diseases were not included in the study. In this study, patients who were admitted to our hospital due to snoring and sleep apnea and were scheduled for surgical treatment were selected.
HDL level, which is one of the risk factors for atherosclerosis, was evaluated in our study
There are studies investigating HDL level in OSAS in the literature. Li et al. 2014, in their study on 158 patients, divided the patients into normal primary snoring group (AHI < 5), mild, moderate, and severe OSAS group according to polysomnography. In addition, according to body mass index (BMI), the primary snoring group was divided into normal BMI and overweight (obese) groups. Compared to the primary snoring group, in normal BMI groups, a decrease in HDL was found in the OSAS group. In the study, no difference was found between the groups with and without OSAS in terms of HDL. However, an increase in HDL levels was detected in all groups after the 5th day after OSAS surgery. Increasing HDL level is a highly desirable situation in atherosclerosis prophylaxis and treatment. It would be appropriate to support this increase with other studies.