Blood Pressure in Older Adults after Meals and Standing Up

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The summary below is from the full report titled "Upright Posture and Postprandial Hypotension in Elderly Persons." It is in the 3 October 2000 issue of Annals of Internal Medicine (volume 133, pages 533-536). The authors are MS Maurer, W Karmally, H Rivadeneira, MK Parides, and DM Bloomfield.

What is the problem and what is known about it so far?

Fainting (syncope) and falls are common in older persons and can result in significant health problems, disability, and even death. With aging, the heart and circulation begin to respond in ways that predispose older persons to fainting and falls, including decreases in blood pressure on standing up (orthostatic hypotension) and after eating (postprandial hypotension). While these changes are thought to be potential factors in syncope and falls in the elderly, few detailed studies of this problem have been done.

Why did the researchers do this particular study?

To determine whether eating worsens the decrease in blood pressure that occurs when older persons stand up.

Who was studied?

The study included 50 independent older persons: 47 persons from senior centers and 3 persons who were admitted to the hospital because of an unexplained fall or syncope. The average age of study participants was 78 years; the youngest was 61 years old, and the oldest was 96 years old.

How was the study done?

The researchers performed tests using a tilt table before and 30 minutes after participants ate a standardized high-carbohydrate meal. The tilt table tilts a person from lying flat to a standing position, making it easy to measure blood pressure and heart rate while the person is in various positions.

What did the researchers find?

Upright position and eating a meal were associated with a fall in blood pressure. The fall in blood pressure seen when these two factors were combined was greater than the fall seen with either one alone. The percentage of patients with low blood pressure and associated symptoms (for example, lightheadedness) was 11% before meals and 22% after meals.

What were the limitations of the study?

The study was done under laboratory conditions rather than in real-life situations. It is not known how many of the study participants whose blood pressure decreased during the test, with or without symptoms, would actually have fainted or had a fall in real life.

What are the implications of the study?

When doctors evaluate an older person who has lightheadedness, syncope, or falls, it may be helpful for them to ask specifically about the relationship of these symptoms to both standing up and meals.