Nightmares and cardiometabolic diseases in an adult population-based sample

Nightmares can trigger stress responses and lead to insufficient or poor-quality sleep, which are associated with cardiometabolic diseases (CMD) and their risk factors. However, research on the association and underlying mechanisms between nightmares and CMD in the general population remains limited.

Data from three follow-ups of the CoLaus|PsyCoLaus study (Lausanne, Switzerland). Frequent nightmares were assessed through questionnaires, with additional ecological momentary assessment (EMA) in the second and third follow-ups. Salivary cortisol levels (as a biomarker of stress), and polysomnographic data including the pulse wave amplitude drops index (PWAD) were also analysed.

Data from 4223, 2850 and 2009 participants from the first, second, and third follow-ups was analysed. Prevalence of frequent nightmares was 11.7%, 8.1% and 7.7% in the first, second, and third follow-ups, respectively. Across three follow-ups, the frequent nightmares group tended to present with higher body mass index and higher prevalence of hypertension and diabetes than the no-nightmare group. EMA data confirmed these findings: multivariable-adjusted odds ratio and (95% CI) for hypertension 2.53 (1.32-4.85) and 1.78 (0.92-3.41) in the second and third follow-ups, respectively. Polysomnography data showed that the frequent nightmares group had a significantly lower PWAD: multivariable adjusted mean ± SE 46.31 ± 1.34 vs. 52.02 ± 0.49. Salivary cortisol levels did not differ between the frequent nightmares and the no-nightmare groups.

Frequent nightmares show a significant association with CMD, although this association should be confirmed. The underlying mechanisms are not fully explained by dysregulation of the hypothalamic-pituitary-adrenalaxis or autonomic nervous system alone.