New York, Jan 14 (IANS): People suffering from asthma are at an increased risk of developing obstructive sleep apnea (OSA), a sleep disorder associated with adversely affecting health and a higher risk of death.

The study added that longer a person suffers from asthma, the risk of developing OSA becomes higher.

"This study found that preexistent asthma was a risk factor for the development of clinically relevant OSA in adulthood over a four-year period,"said Mihaela Teodorescu from University of Wisconsin School of Medicine and Public Health, Madison, US.

"Furthermore, the asthma-OSA association was significantly dose-dependent on duration of asthma," Teodorescu added.

The study involved randomly selected adult employees of state agencies, 30 to 60 years of age in 1988.

Since study inception, participants attended in-laboratory tests and provided health-related questionnaires approximately every four years.

Eligible participants were identified as free of OSA at the study entry.

Participants with preexisting asthma had nearly 40 percent increased risk for new OSA compared with those without asthma.

The study appeared in JAMA, the Journal of the American Medical Association.