Overnight pulse wave analysis to assess autonomic changes during sleep in insomnia patients and healthy sleepers.

Insomnia has been associated with increased cardiovascular (CV) risk, which may be linked to sympathetic activation. Non-invasive overnight pulse wave analysis may be a useful tool to detect early signs of autonomic changes during sleep in insomniacs. Fifty-two participants (26 men, 37±13 years, BMI: 24±5 kg/m2, 26 insomniacs/ 26 controls) underwent overnight polysomnography with pulse oximetry and pulse wave analysis including pulse rate, vascular stiffness (pulse propagation time, PPT), and a composite cardiac risk index based on autonomic function and overnight hypoxia. We identified two subgroups of insomniacs, with and without objectively disturbed sleep (sleep efficiency SE≤80%, n = 14 vs. SE>80%, n = 12), and observed increased pulse rate and vascular stiffness in insomnia cases when diagnosis was based on both, subjective and objective criteria. Both insomnia groups were associated with higher overnight pulse rate than controls (median/ IQR: low-SE (low sleep efficiency): 67/ 58-70bpm; high-SE: 66/ 63-69bpm; controls: 58/ 52-63bpm; p = 0.01). Vascular stiffness was higher (reduction of PPT) in low-SE insomniacs compared with high-SE insomniacs and controls (169/ 147-232ms; 237/ 215-254ms; 244/ 180-284ms; p = 0.01). The cardiac risk index was increased in low-SE insomniacs (0.2/ 0.0-0.7; 0.0/ 0.0-0.4; 0.0/ 0.0-0.3; p = 0.05). Our results suggest a hyperarousal state in young and otherwise healthy insomniacs during sleep. The increased pulse rate and vascular stiffness in insomniacs with low SE suggest early signs of rigid vessels and potentially, an elevated CV risk. Overnight pulse wave analysis may be feasible for CV risk assessment in insomniacs and may provide a useful tool for phenotyping insomnia in order to provide individualized therapy.

Déclaration de conflit d'intérêts

The authors have read the journal's policy and have the following competing interests: LG had a previous collaboration with Weinmann GMBH on the development of pulse wave analysis during sleep. JH has nothing to declare related to the current work. TP reports grants from Cidelec, grants from Löwenstein Medical, grants and personal fees from Philips, grants from ResMed, personal fees from UCB Pharma, outside the submitted work. IF reports personal fees from ResMed, grants from Weinmann, personal fees from Philips, grants from Fisher Paykel, outside the submitted work. Advanced Sleep Research GmbH supported the salary of KL while participating in the study. This does not alter our adherence to PLOS ONE policies on sharing data and materials. None other financial disclosures. There are no patents, products in development or marketed products associated with this research to declare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.