INS and obstructive sleep apnea syndrome: Interestingly, the results of three large-scale population-based cohort studies including more than 145,000 participants demonstrated that the presence of OSA increases the risk of developing T2DM by 37%, independently of demographic, lifestyle and anthropometric factors, while insulin-treated T2DM is strongly correlated with a 43% greater risk of OSA, particularly in women, possibly due to long duration and insufficient glycemic control [29].