A new study conducted on more than 1,255 men and women patients with high blood pressure, aged between 33 to 97-years, with 70 as the average age; suggests that subjects who did not get the standard 7.5-hours of sleep and, witnessed elevated levels of blood pressure on falling asleep, were four times as likely to suffer a stroke, fatal or non-fatal heart attack or die suddenly of cardiac arrest. They had a 68% higher risk of any one of these cardiovascular complications, compared to their better-rested counterparts.

The study conducted at Jichi Medical University in Japan, Columbia University Medical Centre, New York City and Stony Brook University, Stony Brook, N. Y. and published in the Archives of Internal Medicine, saw researchers follow their subjects over a 50-month period, during which they compiled data on their sleep duration, their day and night blood pressure, including cardiovascular history.

However, it should be noted that only sleep deprived study subjects who failed to see the normal blood pressure dip that occurs overnight were at risk. Others who slept less than 7.5-hours, but did not witness a spike in their overnight blood pressure, like their counterparts who slept longer, without experiencing heightened levels of overnight blood pressure, were not at risk of a higher rate of heart disease.

The study findings confirm what doctors have known for long i. e. chronic sleep deprivation results in a number of health problems like coronary heart disease, high blood pressure, diabetes and obesity. Therefore, researchers say, these findings make it imperative that doctors with high blood pressure patients should inquire about their sleep patterns for risk assessment of high blood pressure patients.

Researchers suspect lack of sleep results in increased nervous system activity during the day, which tends to place undue stress on the cardiovascular system. According to study lead - Dr. Kazuo Eguchi of Jichi Medical University, Japan, non-dipping overnight blood pressure is tied to increased nervous system activity during the day, suggesting the combination could have an 'interactive effect to increase cardiovascular risk'.