In a recent meta-analysis of gene polymorphisms for IL-6 and corresponding plasma levels, the authors concluded that IL-6 gene polymorphism -174 G/C, but not -572 G/C, is associated with OSAS risk in adults and that IL-6 levels are globally increased in OSAS but that CPAP treatment does not consistently reduce elevated IL-6 levels [176], the latter being possibly related to underlying obesity or concurrent cardiovascular or metabolic disease [143,176]. Here, IL6 is linked to metabolic disease.