Obstructive sleep apnoea (OSA) is increasingly associated with insulin resistance. The underlying pathophysiology remains unclear but intermittent hypoxia (IH)-mediated inflammation and subsequent dysfunction of the adipose tissue has been hypothesised to play a key role.We tested this hypothesis employing a comprehensive translational approach using a murine IH model of lean and diet-induced obese mice, an innovative IH system for cell cultures and a tightly controlled patient cohort.IH led to the development of insulin resistance in mice, corrected for the degree of obesity, and reduced insulin-mediated glucose uptake in 3T3-L1 adipocytes, associated with inhibition of the insulin-signalling pathway and downregulation of insulin-receptor substrate-1 mRNA. Providing mechanistic insight, IH induced a pro-inflammatory phenotype of visceral adipose tissue in mice with pro-inflammatory M1 macrophage polarisation correlating with the severity of insulin resistance. Complimentary in vitro analysis demonstrated that IH led to M1 polarisation of THP1-derived macrophages. In subjects without comorbidities (n=186), OSA was independently associated with insulin resistance. Furthermore, we found an independent correlation of OSA severity with the M1 macrophage inflammatory marker sCD163.This study provides evidence that IH induces a pro-inflammatory phenotype of the adipose tissue,which may be a crucial link between OSA and the development of insulin resistance.
- obstructive sleep apnea
- intermittent hypoxia
- insulin resistance
- tissue inflammation
Murphy, A., Thomas, A., Crinion, S., Kent, B., Tambuwala, M., Fabre, A., PEPIN, J-L., Roche, H., ARNAUD, C., & Ryan, S. (2017). Intermittent hypoxia in obstructive sleep apnoea mediates insulin resistance through adipose tissue inflammation. European Respiratory Journal, 49, 1-11. https://doi.org/10.1183/13993003.01731-2016