Taking blood pressure

Addressing abnormal nighttime blood pressure changes may reduce mortality in adults with type 1 and type 2 diabetes, a long-term study has found.

Blood pressure normally should fall at night and during sleep. When it remains relatively stable or increases instead — a problem called reverse dipping — it more than doubles the risk of death in diabetic patients, the researchers said.

Participants included 349 adults in Italy who were followed for 21 years beginning in 1999. Most had type 2 diabetes, although 65 had type 1. About 80% had hypertension, mostly uncontrolled. All received ambulatory blood pressure monitoring. Reverse dippers were categorized as those whose blood pressure increased by 0.1% or greater compared to daytime levels.

More than half of the participants had blood pressure that didn’t dip at night, and 20% were reverse dippers. 

Reverse dippers’ face higher risks

Reverse dippers had two-fold greater odds of death from all causes when compared to those whose blood pressure dipped in the normal fashion. They also had a 1.9-fold risk increase in mortality compared with non-dippers, reported Martina Chiriacò, M.D., of the University of Pisa, in Italy. Differences in mortality risk between dippers and non-dippers was not significant. 

The results underscore the importance of diagnosing and treating these blood pressure dipping problems, Chiriacò said. Prior studies have also linked non-dipping to kidney and cardiovascular disease in healthy people and in those diagnosed with diabetes, she noted.

“It is important that healthcare professionals look for abnormal blood pressure dipping patterns in people with type 1 or type 2 diabetes. There are strategies to reduce blood pressure during the night,” she said.

To that end, clinicians should make full use of ambulatory blood pressure monitoring, she and her colleagues added. This screening and monitoring tool is an inexpensive, widely available way to diagnose abnormal blood pressure and heart rate circadian variations, they said.

Full findings will be presented this week at the American Heart Association’s Hypertension Scientific Sessions 2021.