For the study, Marshall's team collected data on 380 men and women, 40 – 65-years-old, who participated in the Busselton Health Study. Among these people, three had severe obstructive sleep apnea, 18 had moderate sleep apnea, and 77 had mild sleep apnea. The remaining 285 people did not suffer from the condition. During 14 years of follow-up, about 33 percent of those with moderate to severe sleep apnea died, compared with 6.5 percent of those with mild sleep apnea and 7.7 percent of those without the condition. For patients with mild sleep apnea, the risk of death was not significant and could not be directly tied to the condition.
People who have, or suspect that they have, sleep apnea should consult their physicians about diagnosis and treatment options. Another study by researchers from the University of Wisconsin has also shown that severe sleep apnea was associated with a three-fold increased risk of dying. In addition, for those with moderate to mild sleep apnea, the risk of death was increased 50 percent compared with people without sleep apnea. Sleep apnea is also linked to future heart attacks and with thickened wall thickness of the neck artery.