From the Guidelines
Not being a "dipper" at night for blood pressure means that a person's blood pressure doesn't naturally decrease during sleep as it should, which is associated with increased cardiovascular risk. Normally, blood pressure follows a circadian rhythm, dropping by 10-20% during nighttime (called "dipping") 1. When this normal dipping doesn't occur, it's called "non-dipping". Non-dipping patterns can be identified through 24-hour ambulatory blood pressure monitoring, which measures blood pressure at regular intervals throughout the day and night 1. This pattern is concerning because it means organs don't get their normal period of lower pressure, potentially leading to heart disease, stroke, and kidney damage over time. Some key points to consider:
- Non-dipping may be caused by sleep disorders, high salt intake, kidney disease, autonomic nervous system dysfunction, or certain medications.
- Treatment often involves adjusting the timing of blood pressure medications (taking some in the evening rather than morning), improving sleep quality, reducing salt intake, and treating any underlying conditions.
- If you've been identified as a non-dipper, discuss with your doctor about possibly taking at least one of your blood pressure medications at bedtime to help restore a healthier blood pressure pattern. According to the most recent guidelines, ambulatory blood pressure monitoring can provide useful prognostic information and help identify non-dipping patterns 1. The American Heart Association recommends using ambulatory blood pressure monitoring to supplement blood pressure readings obtained in office settings 1. In terms of specific values, the suggested upper limit of normal ambulatory pressure is <135/85 for daytime and <120/70 for nighttime 1. However, the most important factor is the presence or absence of a dipping pattern, rather than the absolute values. Overall, being a non-dipper is a significant concern that requires attention and potentially treatment to reduce the risk of cardiovascular complications.
From the Research
Definition of Non-Dipper
- A non-dipper is an individual whose blood pressure does not decrease by 10-20% at night, as compared to daytime blood pressure readings 2.
- This phenomenon is also known as blunted or absent dipping, and it has been linked to an increased risk of cardiovascular events 3, 2.
Characteristics of Non-Dippers
- Non-dippers tend to have higher night-time systolic blood pressure and lower daytime systolic blood pressure compared to dippers 4.
- They are also at risk of undiagnosed or masked hypertension, as their daytime blood pressure readings may be lower than their night-time readings 4.
Risk Factors Associated with Non-Dipping
- Non-dipping has been associated with an increased risk of cardiovascular events, including stroke and total mortality 3.
- However, some studies suggest that reverse dipping (i.e., an increase in blood pressure at night) may be a more significant risk factor for cardiovascular events than non-dipping alone 3, 5.
- Nocturnal hypertension, which refers to elevated blood pressure at night, may also be a more reliable marker of cardiovascular risk than non-dipping status 5.