An association between insomnia and an increased risk of heart attack and stroke has been found in a new meta-analysis. It suggests that women may be slightly more prone, especially for non-restorative sleep.

The study’s first author Qiao He, a Master’s degree student at China Medical University, said:

“Sleep is important for biological recovery and takes around a third of our lifetime, but in modern society more and more people complain of insomnia. For example, it is reported that approximately one-third of the general population in Germany has suffered from insomnia symptoms. Researchers have found associations between insomnia and poor health outcomes. But the links between insomnia and heart disease or stroke have been inconsistent."

The analysis looked at 15 prospective cohort studies of 160,867 people who were followed for an average of three to 29.6 years, examining the relationship between insomnia and incidence of or death from cardiovascular disease.

Symptoms of insomnia can also be associated with restless legs syndrome, hormone shifts such as those that precede menstruation and those during menopause, mental disorders such as bipolar disorder, clinical depression, generalized anxiety disorder, post traumatic stress disorder, schizophrenia, disturbances of the circadian rhythm, such as shift work and jet lag, hyperthyroidism, rheumatoid arthritis and use of psychoactive drugs, particularly stimulants, including certain medications, herbs, caffeine, nicotine, cocaine, amphetamines, methylphenidate, aripiprazole, MDMA, modafinil, or excessive alcohol intake.

Heart Disease Or Stroke Risk

Cardiovascular diseases included acute myocardial infarction, coronary heart disease, heart failure, as well as stroke, or a combination of events. Insomnia symptoms encompassed difficulty initiating sleep, difficulty maintaining sleep, early-morning awakening, and non-restorative sleep.

Miss He added:

“We found that difficulty initiating sleep, difficulty maintaining sleep, or non-restorative sleep were associated with 27%, 11%, and 18% higher risks of cardiovascular and stroke events, respectively. The underlying mechanisms for these links are not completely understood. Previous studies have shown that insomnia may change metabolism and endocrine function, increase sympathetic activation, raise blood pressure, and elevate levels of proinflammatory and inflammatory cytokines - all of which are risk factors for cardiovascular disease and stroke."

The study uncovered significant associations between difficulty initiating sleep, difficulty maintaining sleep, and non-restorative sleep and the risk of future heart disease and stroke, with increased relative risks of 1.27, 1.11, and 1.18, respectively, compared to those not experiencing these insomnia symptoms. There was no association between early-morning awakening and adverse events.

Miss He concluded:

“Sleep disorders are common in the general population and sleep health should be included in clinical risk assessment. Health education is needed to increase public awareness of insomnia symptoms and the potential risks, so that people with sleep problems are encouraged to seek help."

Qiao He, Peng Zhang, Guangxiao Li, Huixu Dai, Jingpu Shi The association between insomnia symptoms and risk of cardio-cerebral vascular events: A meta-analysis of prospective cohort studies European Journal of Preventive Cardiology 10.1177/2047487317702043

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