Dosing at Night to Cause BP 'Dipping'

George L. Bakris, MD


November 17, 2014

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I am Dr George Bakris, professor of medicine and director of the Ash Comprehensive Hypertension Center at the University of Chicago Medicine. Today I want to talk to you about "nocturnal dipping," its importance, and the use of medications to try to convert people who don't dip to dippers.

Nocturnal dipping is normal. All of us should experience nocturnal dipping because it relieves the blood pressure load during sleep. Many people, either because of poor sleep quality, medications they are taking, or the presence of such concomitant illnesses as advanced kidney disease, have a very difficult time dipping at night, and that increases the blood pressure load and enhances stroke risk and risk for myocardial infarction.

Studies published over the past 15 to 20 years that have shown that dosing medications at night can convert people to a dipping status. Recently, there was a nice review[1] of these studies showing that whether you use short-term or intermediate-acting medications, calcium-channel blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers, dosing at night offers an advantage and increases the likelihood of converting people to dipping status from nondipping status.

However, dosing with long-term or long-acting ACE inhibitors (such as fosinopril, perindopril, or trandolapril) or calcium antagonists (such as amlodipine) at night doesn't seem to have the same magnitude of effect as dosing shorter-acting agents. That is because the effect persists.

This is an important concept. If you are thinking about dosing at night, you certainly don't want to dose diuretics at night. That will reduce the likelihood of nocturnal dipping, because the patient will be up going to the bathroom all night. This is a very important point to keep in mind.

What do you gain from dosing patients at night? The highest risk for cardiovascular events occurs in the morning between 6:00 AM and 10:00 AM. This has been known for almost 30 years. You have a greater likelihood of reducing pressure at that time and converting to dipping status.[2] Those are two clear reasons to dose at night if the 24-hour ambulatory monitor shows that it would be appropriate to do so.

Unfortunately, people with advanced kidney disease—those with glomerular filtration rates (GFRs) of 20-30 mL/min—don't seem to be as consistently able as people with normal kidney function (GFR > 60 mL/min) to convert from nondipping to dipping.[3]

Some studies have shown an effect, and some have not shown an effect, of dosing at night,[4,5] and so if you are going to do it, it is worth confirming with a 24-hour monitor to see whether you have been able to convert these people.

I have used dosing at night in people with advanced kidney disease and by and large have failed to see a significant benefit on conversion to dipping status, but there are exceptions. Some studies from Spain suggest that dosing at night might work in people with low GFRs.[6]

This is an important construct, and an important piece of the armamentarium. You need 24-hour ambulatory monitoring in these patients to see the data, but if you think that the patient could benefit from this, it is certainly worth a try, because you will enhance cardiovascular risk reduction through this maneuver.


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