Many, but not all, people with sleep apnea develop high blood pressure. In a new study, Yale researchers show those who develop hypertension have many similarities with pregnant woman with pre-eclampsia.
The findings could shed light on individual risk associated with sleep apnea, which is associated with increased risk of heart disease and stroke. At least 15 per cent of adults suffer from the condition, which is marked by a cessation of breathing during sleep.
''You wouldn't imagine that a 50-year-old obese man would have so much in common with a 30-year-old pregnant woman but they do,'' says Dr. Vahid Mohsenin of the Yale Center for Sleep Medicine and senior author of the study in the Journal of Cardiovascular Disease Research.
Mohensin and co-author Dr. Behrouz Jafari of the University of California-Irvine found subjects with sleep apnea and hypertension had damage to cells lining blood vessels, whether or not oxygen levels were lowered.
Those with hypertension also had elevated levels of soluble endoglin in their blood, which are known to cause hypertension in women with pre-eclampsia.
Endoglin is already used as a marker of placental malformation and development of pre-eclampsia, a potentially dangerous condition marked sudden onset of high blood pressure during pregnancy.
The current study demonstrates that elevated circulating endoglin is also a marker of hypertension and heart disease in patients with obstructive sleep apnea.
The National Institutes of Health funded the study.