Influence of Obstructive Sleep Apnea on Systemic Inflammation in Pregnancy.

Background: Obstructive sleep apnea (OSA) is prevalent in pregnancy and it is associated with adverse pregnancy-related outcomes such as gestational diabetes, pre-eclampsia, and low birth weight. Maternal systemic inflammation is proposed to be one of the main intermediate mechanisms. However, the effects of OSA on systemic inflammation are unknown in normal pregnancy. Methods: Women in the 3rd trimester underwent hospital polysomnography to evaluate whether OSA increases systemic inflammation in normal pregnancy and its potential association with adverse fetal outcomes. OSA was defined as an apnea-hypopnea index (AHI) of ≥ 5 h-1. Plasma cytokines levels (TNF-α, IL-1ß, IL-6, IL-8, and IL-10) were determined by multiple immunoassays. Results: We included 11 patients with OSA and 22 women with AHI < 5 h-1, who were homogeneous in age, and body mass index (BMI). Women with OSA had significant higher levels of TNF-α, IL-1ß, IL-8, and IL-10. We found significant correlations between AHI during REM and TNF-α (r = 0.40), IL-1ß (r = 0.36), IL-6 (r = 0.52), IL-8 (r = 0.43), between obstructive apnea index and TNF-α (r = 0.46) and between AHI and IL-1ß (r = 0.43). We also found that CT90% was related to IL-8 (r = 0.37). There were no significant differences in neonatal characteristics; however, we found inverse correlations between TNF-α and IL-8 with birth weight (both r = -0.48), while IL-8 showed a significant inverse relationship with neonatal gestational age (r = -0.48). Conclusions: OSA in our normal pregnancy population was associated with higher systemic inflammation, which was related to obstructive events, especially during REM sleep. Moreover, systemic inflammation was inversely correlated with neonatal birth weight and age.

Red cell distribution width: a new tool for the severity prediction of sleep apnoea syndrome in children.

INTRODUCTION: Red cell distribution width (RDW) is a parameter included in the complete blood count which informs about the size of the circulating red blood cell population and its distribution. In adults, an increase in RDW was shown to be associated both with obstructive sleep apnoea (OSA) and with an increase in cardiovascular mortality. The aim of this study was to determine whether RDW is a potential biomarker for screening children with moderate-severe OSA. METHODS: An observational study in snoring patients was performed. All patients underwent a sleep study and were classified either as simple snorers (apnoea-hypopnoea index (AHI) <1 event·h-1) or as patients with OSA (mild AHI ≥1 to <5 events·h-1; moderate-severe AHI ≥5 events·h-1). Blood analyses (complete blood count and C-reactive protein) were performed for every individual. RESULTS: A total of 175 individuals were recruited. The mean age was 8.3±3.6 years. Correlation studies between RDW and several sleep-related parameters showed negative significant associations with minimum oxygen saturation, and positive significant associations with oxygen desaturation index (≥3% and ≥4%), AHI and the arousal index. A predictive model for paediatric severe OSA (AHI ≥5 events·h-1) was found based on mean corpuscular haemoglobin concentration (MCHC) <34.9 g·dL-1 and RDW >13.1% values, adjusting for body mass index z-score and age (area under the curve 0.657; p=0.004). In addition, differences were found in eosinophil count and C-reactive protein concentrations among the three subgroups. CONCLUSIONS: In children, RDW stands out as a biomarker associated with the severity of OSA. The use of RDW and MCHC could be a simple but useful tool for the severity prediction of paediatric OSA in snoring patients.