Sleep and cardiovascular risk

ESC 2018 Several studies point towards that both short and long sleep duration, as well as fragmented sleep increase CV risk in healthy subjects. Indian raga music can improve sleep patterns.

Several studies presented at ESC 2018, investigated the relationship between sleep and cardiovascular (CV) risk. The results point into the direction that both short and long duration of sleep, but also fragmented sleep increases the CV risk in healthy persons, compared to normal sleep duration of 7-8 hours per night. Moreover, Indian raga music can reduce heart rate, anxiety levels and improve feelings and may therefore improve sleep patterns.

Fountas et al. investigated the relationship between daily sleep duration and morbidity/mortality from CVD in adults without CVD at baseline, by performing a meta-analysis on 11 prospective studies of the last five years (n=1,000,541). They showed data that suggest that <6 hours and >9 hours of sleep are associated with a higher risk of developing or dying from CV disease (RR=1.11, 95C%CI: 1.03-1.19, p=0.007 and RR:1.31, 95%CI: 1.22-1.43, p<0.001, respectively), compared to 6-8 hours of sleep (n=1,000,541). This is in concordance with results of Bengtsson et al. who investigated the effect of short sleep duration on major adverse cardiovascular events (MACE) risk in a prospective cohort study (1993-2014, n=760). They demonstrated an association between <5 hours of sleep and an increased risk of MACE (HR: 2.15, 95%CI: 1.28-3.61), in comparison with normal sleepers. Rodriquez et al. specifically investigated the association between sleep parameters and subclinical atherosclerosis in 3974 asymptomatic middle-aged participants. They presented similar results, namely that sleep duration <6 hours was independently associated with increased atherosclerotic burden and more affected vascular territories measured with 3D VUS (OR: 1.19, 95%CI: 1.00-1.42, p=0.05 and OR: 1.23, 95%CI: 1.03-1.47, p=0.02, respectively), compared to normal sleep duration. No differences were seen in inflammatory and aging biomarkers and sleep parameters. However, short sleepers showed metabolic syndrome more frequently.

Moreover, Rodriquez et al. also studied the role of quality of sleep in CV risk. Participants (n=3974) with more fragmented sleep had a higher risk of non-coronary atherosclerosis, demonstrated by more affected territories (OR: 1.35, 95%CI: 1.05-1.65, p=0.01), compared to normal sleep duration.

Despite these insights, it remains unknown whether or not short and long sleep duration play a causal role in CV risk.

Thus, improvement of sleep deprivation is important in the reduction of CV risk, but how can sleep patterns be improved? This question was answered by Sen et al. who evaluated the effect of exposure to Indian raga music on heart rate variability (HRV) in a cohort study (n=149). After sessions of listening to Indian raga music, heart rate was reduced (P<0.03), as a result of lower sympathetic activity and/or increased vagal modulation with reduced anxiety levels (P<0.004) and positive change in feelings (P<0.005), compared to pop music or silence.

On average, adults spend a third of their life on sleeping and 10% suffer from sleeping disorders. This can be related to several pathophysiological mechanisms, including sympathetic nervous system activation, disturbance of glucose metabolism, decreased levels of plasma NO2 and inflammation, which in turn can affect CV health. It should be noted however, that reports regarding the association between sleep patterns and CV risk are contradictory.

This press conference enlightened the association between sleep and CV risk. Fountas: ‘My message to physicians is that consultation for proper sleep duration may result in better results in primary prevention of CVD and patients should sleep well, not too long, and not too short’.

- Our reporting is based on the information provided at the ESC congress –