New research from the Mayo Clinic finds that sleep apnea is highly prevalent among retired National Football League (NFL) players, particularly in linemen.

The recent study included 167 retired NFL players who underwent home sleep studies. Results show that 60% of linemen, average age of 54, had sleep-disordered breathing (SDB). The linemen in the study had an average of 18.1 sleep-related breathing disorder episodes per hour. For the rest of the study participants, who played positions other than lineman and were average age of 53, 46% had SDB, with an average of 13.4 episodes per hour. Age and obesity were significantly associated with SDB in the retired players.

Additionally, 45% of the linemen and 32% of nonlinemen reported having high blood pressure.

The prevalence of SDB and obesity were higher than expected by lead researcher Virend Somers, MD, PhD, a Mayo Clinic cardiologist, according to a release on the study. Somers cautions that this study should serve as a warning to athletes that they should monitor their weight and health carefully when they retire.