Study Finds Inflammatory Parameters Higher in Patients With Obstructive Sleep Apnea After CPAP

A recent study found that inflammatory parameters were reduced in patients with obstructive sleep apnea syndrome after using continuous positive airway pressure (CPAP) treatment.

A study published in Sleep and Breathing found that patients with obstructive sleep apnea syndrome (OSAS) had higher inflammatory parameters compared with healthy patients. Inflammation regression was also detected after continuous airway pressure (CPAP) treatment.

Patients aged 18 to 65 years were included in this study if they underwent a polysomnography (PSG) test between January 1, 2019, and December 31, 2019. Patients were excluded if they had a known systemic disease, malignancy, chronic drug use, or were pregnant. Patients were grouped into categories of normal (apnea-hypopnea index [AHI] <5), mild to moderate OSAS (AHI 5-30/h) and severe OSAS (AHI ≥ 30/h).

The patients were called for follow-up after 3 months and follow-up examinations were performed for any patient who received PAP treatment at least 6 days/week for at least 4 hours/day.

There were 92 patients included in the study, including 25 controls, 39 patients with mild to moderate OSAS who did not receive CPAP treatment, and 28 patients with severe OSAS for whom CPAP treatment was initiated. Body mass index (BMI) was higher and men more prominent in the group with severe OSAS.

Statistically significant differences were found in the inflammation parameters analyzed, including periostin. Periostin positively correlated to AHI and oxygen desaturation index (ODI) but was negatively correlated with minimum saturation and mean saturation. Periostin values increased as the severity of OSAS increased when BMI values were adjusted.

Tumor necrosis factor (TNF)-α, transforming growth factor (TGF) β-1, and interleukin (IL)-6 demonstrated a positive correlation with AHI and ODI, and a negative correlation with minimum saturation. IL-6 and desaturation time also had a positive correlation.

In patients with severe OSAS, significant decreases were detected in TGF β-1, TNF-α, and IL-6 values from before PAP treatment to after 3 months of PAP treatment. There was also a decrease in the periostin values, but it was not statistically significant.

There were some limitations to this study. It was not a randomized controlled study, as it was difficult to include an untreated control group of patients with OSAS. Only the 3-month results of CPAP treatment were evaluated, with earlier and later dates not examined. The study was conducted in a single center and the number of people may not have been enough to identify statistical significance.

The researchers concluded that the fact that OSAS causes inflammatory marker increases supports the idea that OSAS is a systematic disease.

“We think that the increase in TNF-α and periostin in patients with OSAS may guide further studies and be useful in predicting the severity and prognosis of OSAS,” the authors wrote.

Reference

Tosun F, Babyigit C, Dikmen N, Dogan S, Dirican E. The effect of continuous positive airway pressure treatment on inflammatory parameters and periostin levels in patients with obstructive sleep apnea syndrome. Sleep Breath. Published online April 27, 2022. doi:10.1007/s11325-022-02616-z