Poor Sleep Plus Hypertension Equals Greater Risk For Heart Disease

Not sure how much sleep is enough? Those zzzz's are more important than you might think. Getting less than seven and a half hours of sleep nightly can increase your risk for heart disease and stroke. In addition, when the lack of sufficient sleep is accompanied by hypertension, you may be at an even greater risk for cardiovascular complications.

Researchers have reported that people with high blood pressure who do not get the standard amount of sleep may be faced with a significant increase risk of heart disease and stroke. In a study of Japanese adults with hypertension, findings indicated that those who slept less than seven and one half hours nightly were more likely to suffer from a heart attack, stroke or even die of cardiac arrest. Those most at risk are so called "short sleepers" who, in addition, do not experience the blood-pressure decline that normally occurs overnight during rest.

According to the researchers, led by Dr. Kazuo Eguchi of Jichi Medical University in Japan, there are only a comparatively small number of people who are both short sleepers and do not have an overnight decline in blood pressure. The group notes, “It is a group that could be easily identified and monitored more closely.”

The study results were based on data from 1,255 men and women, ages 33 to 97, who suffered from high blood pressure. The average age in the group of participants was 70. The researchers recorded each participant's blood-pressure changes over a 24-hour period using portable blood pressure monitor. The patients were then followed over an average of a 50- month period of time in which there were 99 heart attacks, strokes or deaths stemming from cardiac arrest.

Overall, those who slept for less than 7.5 hours per night were shown to have a 68-percent higher risk of cardiovascular complications than people who get sufficient rest. The authors write, “The incidence of cardiovascular disease was 2.4 per 100 person-years in subjects with less than 7.5 hours of sleep and 1.8 per 100 person-years in subjects with longer sleep duration.”
For study participants who had no decline of their overnight blood pressure, the risk was even greater. But, the highest risks were found among short sleepers who also lacked the decline in blood pressure overnight. The risk for this group was more than quadruple the risk of well-rested people.

The consensus of the researchers is that sleep deprivation as well as non-dipping overnight blood pressure lead to an increase in nervous system activity during the day that places undue stress on the cardiovascular system. The combination of the two may therefore have an “interactive effect to increase cardiovascular risk.”

Wrapping up the study report, the authors note, “In conclusion, shorter duration of sleep is a predictor of incident cardiovascular disease in elderly individuals with hypertension,” particularly when it occurs with elevated nighttime blood pressure. “Physicians should inquire about sleep duration in the risk assessment of patients with hypertension.” The report on the analysis can be found in the Archives of Internal Medicine.

Recurring sleep deprivation has also been associated with increased risk of other health issues such as diabetes and coronary heart disease and obesity. Sleep disturbances such as those caused by sleep apnea, have also been found to contribute to cardiovascular health issues according reports based on sleep apnea studies conducted earlier this year.