Blood pressure is a very important measurement for people with diabetes. Blood pressure that is too high is strongly linked to serious complications, including early heart disease and kidney damage. High blood pressure is also a major risk factor for eye and nerve damage. We know that, in general, blood pressure normally dips during sleep. When this does not happen, it is called “non-dipping.” Non-dipping is a risk factor for people with type 2 and type 1 diabetes as well as for those without diabetes. Similarly, higher blood pressure at night compared to during the day (“reverse dipping”) is also a significant risk factor for heart and kidney disease.
Comparing blood pressure at night with daytime
In a new study, researchers looked at the long-term effects of non-dipping and reverse dipping on blood pressure in 349 adults. Of these participants, 284 had type 2 diabetes and 65 had type 1 diabetes. Most (82%) also had high blood pressure. Blood pressure was assessed by 24-hour monitoring where participants wore a device continuously that made repeated blood pressure measurements. Researchers monitored the participants over the next 21 years. They found that more than half of the participants were non-dippers and 20% were reverse dippers.
24-hour blood pressure monitoring helps measure risk
The researchers reported that, compared to people whose blood pressure dips during sleep, life expectancy was shortened by 2.5 years for the reverse dippers. Additionally, life expectancy was shortened by just over one year for non-dippers. Reverse dippers also showed signs of blood pressure damage to the heart. They also found that participants with high blood pressure only during the night were at greater risk of early death with a loss of 1.2 years of life. In this study, most participants were White. We know that non-dipping is more common in the Hispanic/Latino and Black populations.
Are you a dipper or reverse dipper?
The researchers concluded that 1 in 10 people with type 2 or type 1 diabetes could be a reverse dipper. This more than doubles the risk of early death from any cause over 21 years. Use of 24-hour blood pressure monitoring would provide doctors with more data to optimize treatment of high blood pressure.