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Roles of interleukin (IL)-6 gene polymorphisms, serum IL-6 levels, and treatment in obstructive sleep apnea: a meta-analysis

  • Sleep Breathing Physiology and Disorders • Original Article
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Abstract

Background

Inconsistent results regarding the relationship between interleukin (IL)-6 gene polymorphisms, serum IL-6 levels, and the treatment in obstructive sleep apnea (OSA) have been reported. This meta-analysis assessed the associations between IL-6 gene polymorphisms and OSA susceptibility, IL-6 levels in OSA, and CPAP (continuous positive airway pressure) and T&A (tonsillectomy and adenoidectomy) therapy for IL-6 in OSA.

Methods

Studies regarding IL-6 polymorphisms, serum IL-6 levels, and OSA treatment were identified using PubMed and Embase. The associations between IL-6 gene polymorphisms and OSA risk (estimated by pooling odds ratios (ORs) with 95 % confidence intervals (CIs)) were assessed using an allele model. The pooled standardized mean differences (SMDs) with 95 % CI of IL-6 were estimated using a random-effects model. Meta-regression, sensitivity analysis, and publication bias were also evaluated.

Results

In total, 53 studies were included. In adults, a significant association between -174 G/C and OSA susceptibility was observed (OR = 1.46, 95 % CI = 1.14–1.87) and IL-6 levels were higher in OSA compared to controls (SMD = 1.56, 95 % CI = 1.18–1.95); however, no association was observed for the -572 G/C allele (OR = 1.13, 95 % CI = 0.87–1.47) and OSA susceptibility and there was no significant change in IL-6 in pre- and post-CPAP therapy (SMD = −0.24, 95 % CI = −0.73 to 0.26). In children, IL-6 levels were also higher in OSA (SMD = 1.27, 95 % CI = 0.29–2.26) and T&A treatment significantly decreased them (SMD = −0.97, 95 % CI = −1.72 to −0.22).

Conclusions

This meta-analysis indicates that the IL-6 gene polymorphism -174 G/C, and not -572 G/C, is associated with adult OSA risk. Although IL-6 levels increased in OSA, CPAP did not significantly suppress them in adults with OSA. In children with OSA, IL-6 levels also increased and T&A therapy significantly decreased them.

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    Authors and Affiliations

    1. Department of Respiratory Diseases, The Second Affiliated Hospital of Soochow University, 1055 Sanxiang Road, Suzhou, 215004, China

      Anyuan Zhong & Minhua Shi

    2. Department of Endocrinology, The Affiliated Drum Tower Hospital, Nanjing Medical University, Zhongshan Road 321, Nanjing, 210008, China

      Xiaolu Xiong

    3. Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, 600 Yishan Road, Shanghai, 200233, China

      Huajun Xu

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    1. Anyuan Zhong
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    Anyuan Zhong and Xiaolu Xiong contributed equally to this work.

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    Zhong, A., Xiong, X., Shi, M. et al. Roles of interleukin (IL)-6 gene polymorphisms, serum IL-6 levels, and treatment in obstructive sleep apnea: a meta-analysis. Sleep Breath 20, 719–731 (2016). https://doi.org/10.1007/s11325-015-1288-6

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