Chronic insomnia is characterised by difficulty initiating and maintaining sleep, waking up too early, non-restorative sleep, and daytime impairment, experienced for 6 or more weeks (American Academy of Sleep Medicine, 2005). Its prevalence is estimated at 50.0% of the general population worldwide (Irish et al, 2015; Kredlow et al, 2015). The experience of chronic insomnia is associated with an increased risk for chronic diseases, cardiovascular diseases in particular (King et al, 2008; Tsunoda et al, 2015). Evidence from cross-sectional and longitudinal studies demonstrates a significant relationship between insomnia and risk of cardiovascular diseases, after controlling for sleep disorders that are physiological in nature (e.g. sleep apnoea) and for other risks of cardiovascular diseases, such as smoking, low levels of physical activity, and alcohol and caffeine consumption (Foley et al, 2004; Phillips et al, 2007; Hoevenaar-Blom et al, 2011). This evidence suggests that non-physiological factors contribute to the risk of cardiovascular diseases in persons with chronic insomnia. Stress, manifested as anxiety and depression, is often experienced by persons with chronic insomnia (Specchio et al, 2004; Taylor et al, 2007), and those with anxiety report cardiovascular symptoms such as chest pain and dyspnea (Ketterer et al, 2008). There is limited research exploring the contribution of psychological (i.e. insomnia, anxiety, and depression) or physical factors (smoking, physical activity, and alcohol and caffeine consumption) to the experience of cardiovascular symptoms (which are indicative of cardiovascular diseases) among adults with chronic insomnia.
Fredericks, S., Sidani, S., Miranda, J., & Fox, M. ( 2016). Examining cardiovascular symptoms in adults living with chronic insomnia. British Journal of Cardiac Nursing, 11(9), 430-436. doi:10.12968/bjca.2016.11.9.430