FRIDAY, April 10, 2026 (HealthDay News) -- High night-to-night variability in obstructive sleep apnea (OSA) severity is associated with increased odds of nonfatal major adverse cardiovascular and cerebrovascular events (MACCE), according to a study published online March 26 in SLEEP.
Bastien Lechat, Ph.D., from Flinders University in Adelaide, Australia, and colleagues examined the association of multinight OSA severity and night-to-night variability with the prevalence of non-fatal MACCE in a study involving 3,159 participants.
The researchers identified 142 MACCE cases (4.5 percent). The odds of MACCE were higher for participants with moderate-to-severe OSA compared with those without OSA (odds ratio, 1.45; 95 percent confidence interval, 0.93 to 2.25). Independent of OSA severity and other confounders, high night-to-night OSA variability (75th versus 25th: 8.0 versus 2.8 events/hour) was associated with increased odds of having an MACCE (odds ratio, 1.34; 95 percent confidence interval, 1.04 to 1.72).
"Many people assume sleep apnea is stable, but the reality is very different, and some nights can be much worse than others, and this repeated up-and-down strain may place extra stress on the heart," Lechat said in a statement. "A single night sleep test may falsely reassure some patients, because people with mild average sleep apnea can still be at higher risk if their breathing problems swing dramatically between nights."
Several authors disclosed ties to the biopharmaceutical and medical device industries.