We all commonly understand that sleep is important, but a new study has attempted to define just how much quality of sleep can impact quality of life, mainly in terms of its relationship with cardiovascular disease. In particular, this study aimed to see if sleep quality could improve health outcomes for those with a genetic vulnerability to cardiovascular disease.
For the study, researchers observed the genetic variation known as SNP (single nucleotide polymorphisms) that have already been linked with stroke and heart disease. Analyzing the SNPs from 385,292 blood samples from healthy participants in the UK Biobank project, they created a genetic risk score to predict which participants had high, intermediate, and low risk for these issues.
Asking several lifestyle and sleep behavior questions, the team devised a healthy sleep score of 0 to 5, from lowest quality to highest. Each participant was followed for, on average, 8.5 years; over this course of time, 7,280 cases of heart disease or stroke emerged.
According to lead study author Dr. Lu Qi, this study is different from other sleep studies in that the team analyzed sleep behaviors in combination with each other. Professor Qi comments, “We wanted to test whether the relation between sleep scores and cardiovascular outcomes was different according to the genetic risk. This is the first time this has been done.
The Tulane University Obesity Research Center professor of epidemiology goes on to say, “We also wanted to estimate the proportion of cardiovascular problems that would not have occurred if all participants had a healthy sleep patter, if we assume there is a causal relationship.”
Thus, the research team compared sleep scores of 0-1 (which is classified as unhealthy sleep patterns) to those with a score of 5. The higher scores had a 35 percent reduction in risk for cardiovascular disease as well as a 34 percent reduction in risk for both stroke and heart disease.
Dr. Qi concludes, then, “We found that when we put all the behaviors together, the association between sleep and cardiovascular disease was even stronger than with each behaviors separately.”
The results of this study have been published in the European Heart Journal