Delta Wave Activity During Sleep May Be Valuable Predictor for CVD Risk

Disrupted delta wave activity during sleep is associated with the long-term risk for cardiovascular disease (CVD) and CVD mortality. This suggests delta wave activity may be a useful tool to identify individuals at risk for CVD and mortality. These are the findings of a study published in the Journal of the American College of Cardiology.

To evaluate whether delta wave activity during sleep could predict long-term CVD and CVD mortality risks, an international team of researchers used overnight polysomnograms (PSGs) and a spectral entropy-based method.

The researchers looked at data from 2 large cohorts of middle-aged and older adults: the Sleep Heart Health Study (SHHS; 4057 participants; average follow-up, 11.0 years) and the Osteoporotic Fractures in Men Study (MrOS; 2193 participants; average follow-up, 15.5 years).

During follow-up periods, 729 participants in the SHHS group vs 547 participants in the MrOS group had incident CVD; 129 participants in the SHHS group vs 391 in the MrOS group died due to cardiovascular disease.

Multivariable Cox regression models showed a link between lower delta wave entropy and the following:

• higher coronary heart disease (CHD; SHHS: hazard ratio [HR], 1.46; 95% CI, 1.02-2.06; MrOS: HR, 1.79; 95% CI: 1.17-2.73),
• CVD (SHHS: HR, 1.60; 95% CI, 1.21-2.11; MrOS: HR, 1.43; 95% CI, 1.00-2.05), and
• CVD mortality (SHHS: HR, 1.94; 95% CI, 1.18-3.18; MrOS: HR, 1.66; 95% CI, 1.12-2.47).

The associations persisted after adjusting for covariates.

Participants in the SHHS were younger on average (62.4 years vs 72.6 years), with a lower rate of hypertension (32.8% vs. 37.7%) and diabetes (5.6% vs. 7.8%). The MrOS cohort group had poorer quality sleep. Kaplan-Meier survival analysis found that individuals in the lowest percentile of delta entropy had notably higher risks for CHD, CVD, and CVD mortality.

Study limitations included its observational nature and reliance on PSG; not accounting for confounders such as physical activity, insomnia, and mental disorders; reliance on a single-night home-based PSG; and a focus on spectral entropy.

“Our results suggest that low delta wave entropy during sleep may better predict the risk of long-term CVD and CVD mortality than traditional manually derived sleep parameters, and this association is independent of common CVD risk factors,” the researchers concluded.

Disclosure: One study author declared support by national research funding in China and a scientific sponsorship program. Please see the original reference for a full list of author disclosures.