How Sleep Duration Affected Blood Pressure?

According to the United States Centers for Disease Control and Prevention, adults normally need between 7 and 9 hours of sleep. However, the sleep duration of many adults is far less than the recommended.

In fact, several studies have reported the negative health consequences of short sleep duration. Studies have shown lack of sleep would raise rates of obesity, depression and high blood pressure in children, and it would increase the risk of falls for older adults. For the middle-aged persons, lack of sleep would increase the risk of infections, heart disease, stroke and cancer.

It is widely believed that high blood pressure, if not treated in time with medications, could cause stroke and eventually lead to partial or total disability. Some serious cases could even result in death. In the meantime, one should not forget that high blood pressure has long been regarded as a known risk factor of heart disease.

A paper published on June 8, 2009 in the Archives of Internal Medicine by researchers from the University of Chicago revealed that middle-aged adults who sleep too little are more likely to develop hypertension (high blood pressure).

The new study is believed to be among the first to directly measure sleep duration for middle-aged adults. The findings showed that a person who misses an average of 1 hour of sleep over a period of 5 years would raise the risk of getting high blood pressure by 37 percent. Meanwhile, the study also suggested that poor sleep might well explain in part why black men have higher blood pressure risks.

In the study, 578 adults with an average age of 40 were examined. The researchers took blood pressure readings and measured sleep duration for each of these adults. It was noted that only 1 percent slept 8 hours or more.

On average, the volunteers slept only 6 hours. For those who slept less, chances they would develop high blood pressure over 5 years would be much higher. The result also showed that every hour of lost sleep raised the risk. Meanwhile, the researchers found that men, and particularly black men, had much shorter sleep duration than white women in the study, who were least likely to develop high blood pressure.

Sleep Adequately to Prevent Heart Disease!

If a person reduces his or her sleep duration, then his or her risk of getting heart disease would be higher.

A recent study indicated that sleeping less than 7.5 hours a night would increase the chance of cardiovascular risk, including heart attack and stroke, by 33 percent. The paper was published by researchers from Jichi Medical University on November 12, 2008 in the Journal of the American Medical Association's Archives of Internal Medicine.

The sleep of 1,255 people with hypertension (also known as high blood pressure) was monitored by the Japanese researchers for an average period of 50 months. Their daytime and nighttime blood pressure, sleep duration, and cardiovascular disease events like heart attack, stroke and sudden cardiac death were tracked.

In the study, there were 99 incidents of cardiovascular disease being recorded. It was also found that the rate for people who slept less than 7.5 hours was 2.4 per 100 person-years. Those who slept more had a lower incident rate of 1.8 per 100 person-years. Meanwhile, the researchers also discovered that people whose blood pressure rose at night were more prone to heart disease.

The researchers believed that shorter duration of sleep is actually a predictor of incident cardiovascular disease in elderly individuals with hypertension.

In the meantime, inadequate sleep has also been linked to higher chances of diabetes, obesity and several risk factors for cardiovascular disease, which includes nighttime hypertension and sleep-disordered breathing.

What Is the Link Between Sleep Duration and Stroke?

I used to hear from friends or relatives that one should sleep at least 8 hours per night to stay healthy. Is this a justified statement? Does it mean that we should sleep as long as we can?

In reality, “the more is better” may not be true, at least not for the sleep duration.

A report published in July 2008 in the medical journal “Stroke” indicated that middle-aged women who slept 9 hours or more per night would have their risk of stroke increased by 70 percent. This is the finding obtained by United States researchers from the University of North Carolina in Chapel Hill.

Although a number of studies have established a link between sleep duration and mortality, there is still a lack of evidence to associate sleep patterns and cardiovascular disease.

Of the 93,175 women of age between 50 and 79, who were enrolled in the Women’s Health Initiative Study, 8.3 per cent normally slept no more than 5 hours per night, while 4.6 percent slept at least 9 hours per night.

At the end of the study (span over a period of average of 7.5 years), it was found that 1,166 women got ischemic stroke. This is the most common type of stroke, which occurs when blood vessels in the brain block. When this happens, oxygen will be prevented from reaching the brain and will thus cause the brain's tissue to die.

When comparing with women sleeping 7 hours, those slept 6 hours or less, 8 hours, or 9 hours or more increased the risk of stroke by 14 percent, 24 percent, and 70 percent, respectively.

For women who slept 6 hours or less and had cardiovascular disease at the beginning of the study, their chance of getting stroke was increased by 22 percent. Furthermore, women who slept longer hours during the night were not associated with frequent snore or sleepiness. Therefore, sleep during, either shorter or longer than the norm (7 hours), could be independent risk factors for stroke.

Women sleeping long hours during the night is not so common than those who slept less than 6 hours, therefore, the overall health impact of a short sleep is probably greater than long sleep.

However, the researchers caution that their data do not imply that women of long sleep duration would cut their risk of stroke if they reduce their sleep duration. Further studies are still required to help understand the possible mechanisms behind the associations found in this study.

How Does Sleep Duration Link To Childhood Obesity?

Childhood obesity is a tough issue and many health experts have attributed such disorder to unhealthy diets and sedentary lifestyle. However, a recent study has found that children who lack enough sleep face a greater risk of becoming obese than kids who get a good night's sleep.

An analysis of epidiomogical studies by the researchers from Johns Hopkins Bloomberg School of Public Health revealed on February 5, 2008 that each extra hour of sleep cuts a child's risk of becoming overweight or obese by 9 percent. In comparison, children who got the least sleep had a 92 per cent higher chance of being overweight or obese than children who slept enough.

The researchers reviewed 17 published studies on sleep duration and childhood obesity, and the finding was published in the journal Obesity. The results clearly shows there is association between sleep duration and the risk for overweight or obesity in children, and the risk decreased with more sleep.

When comparing with other measures, desirable sleep behavior may be an important low cost means to prevent childhood obesity. As such, it should be considered in future intervention studies, as recommended by the researchers.

The findings may also have important implications for societies where children with insufficient sleep due to the pressure for academic excellence and where the rate of obesity is rising, such as in many East Asian countries.

As recommended and supported by other researches, those children under 5 years old sleep 11 hours or more a day, while children age 5 to 10 should get 10 or more hours of sleep, and children older than 10 should sleep at least 9 hours.

One should bear in mind that childhood obesity may lead to many chronic diseases such as heart disease, high blood pressure, diabetes, etc. when these obese children become adults later on.