Obstructive Sleep Apnoea Syndrome (OSAS) and obesity are linked by a bidirectional causality, where the effects of one affect the other. The factors most involved in the association between OSAS and obesity are oxidative stress, systemic inflammation, and gut microbiota. Moreover, there is a potential link between reduced lung function due to sharing common or similar inflammatory processes and the risk of non-alcoholic fatty liver disease (NAFLD). Therefore, we hypothesize that decreased lung function could be a contributory factor to the development of NAFLD. Electronegative LDL (L5), a promising clinical biomarker for cardiovascular disease, has an important role in (cardiovascular disease) CVD risk assessment. So, L5 may be a potential biomarker for such dual organ interactions and related diseases, too.