REM-Obstructive Sleep Apnea Associated with Early Signs of Atherosclerosis

Mirjam Ljunggren, MD

A new investigation found that rapid eye movement obstructive sleep apnea (REM-OSA) was associated with early signs of atherosclerosis, though the association remained unclear.

Additionally, an association between severe REM-OSA and intima thickness was observed in women patients.

In previous research, obstructive sleep apnea had been associated with increased risk of cardiovascular and notable for being aggravated during REM sleep. Furthermore, REM-OSA had been related to arterial hypertension and non-dipping blood pressure.

Investigators led by Mirjam Ljunggren, MD, Uppsala Univeristy in Sweden, investigated the association between REM-OSA and carotid intima thickness in a community-based sample of men and women in order to detail the potential sex differences.

The study population consisted of 400 women featured in the follow-up, community-based cohort study titled Sleep and Health in Women (SHE). A total of 400 age and body mass index-matched men from Men in Uppsala: a Study of sleep, Apnea, and Cardiometabolic Health (MUSTACHE) were also enrolled.

All women from the SHE study who had a polysomnography (PSG) test and all men from the MUSTACHE study were required to undergo a high-resolution ultrasonography of the common carotid artery, and all patients underwent whole-night ambulatory PSG using the same equipment from both studies.

Investigators used cut-offs for the apnea-hypopnea index (AHI) to categorize OSA by no (<5 events/h), mild (5 to <15 events/h), moderate (15 to <30 events/h), and severe (≥30 events/h) disease.

The team also utilized questionnaires to collect data on daytime symptoms, lifestyle factors such as smoking and alcohol consumption, medical history, and medication.

Following the PSG, fasting blood samples were collected from each participant for the analysis of C-reactive protein (CRP) and low-density lipoprotein (LDL), and participants were examined with high-resolution ultrasonography to assess intima thickness.

After some exclusions, the final study population consisted of 338 men and 253 women, 157 of whom (26.6%) had severe REM-OSA.

Additionally, participants with severe sleep disordered breathing tended to be older with a higher BMI with a typically diagnosis of hypertension than participants with REM-AH or AHI <30 events/h, respectively.

Investigators observed an association between sleep apnea during REM sleep and thicker carotid intima, which remained after adjustments (P=0.032). The team also noticed that intima was increased 9.9% in the group with severe sleep apnea during REM sleep.

This association also remained after adjustment for confounders (adjusted β = 0.043, p = 0.021).

More women were shown to have swevere sleep apnea during REM sleep, and an association between sleep apnea during REM sleep and intima thickness was observed in this patient population in a sec-stratified analyses.

As such, investigators concluded that severe REM sleep apnea was independently associated with signs of atherosclerosis, an association that was more common in female participants.

“To properly treat REM-OSA, it is important that the treatment covers the early morning hours when much of the REM sleep occurs,” the team wrote. “This might be especially important to protect women from additional risk for atherosclerosis from residual untreated REM-OSA, as women have a greater proportion of their OSA in REM sleep.”

The study, "Rapid eye movement sleep apnea and carotid intima thickness in men and women: a SHE-MUSTACHE cohort study," was published online in Journal of Sleep Research.