For people with diabetes, high blood pressure poses a special threat, multiplying their risk of heart attacks, strokes and kidney problems.

But a new study finds that even when people with diabetes show up in their doctor's office with a high blood pressure reading, there's only a 50-50 chance that each of them will get some sort of attention for it. That might mean a change to their medications, or a plan to follow up a few weeks later to see if the reading is still high.

What happens the other 50 percent of the time? Something that others have termed "clinical inertia" takes over, say the University of Michigan Health System and VA Ann Arbor Healthcare System researchers who conducted the study, which is appearing in the May 20 issue of the Annals of Internal Medicine.

The fear is that this lack of response to high blood pressure readings at clinic visits could mean that patients' pressures will keep getting worse.

The study takes a look at possible causes of clinical inertia and finds little evidence supporting the idea that providers are just "ignoring" blood pressure problems.

What really seems to have an impact on treatment decisions is plain old uncertainty about whether the blood pressure is really elevated, or providers being occupied with other medical issues. Providers might need to spend the visit addressing more pressing problems, some of which, like pain, may be contributing to elevated blood pressures. Or, they might take another reading and conclude there's no need for action. Or, patients may report that their pressure readings at home have been fine.

More systematic guidelines for monitoring blood pressure in people with diabetes, and better guidance for when to change treatment when pressures get too high, are needed, say the researchers. They're led by Eve Kerr, M.D., MPH, and Timothy Hofer, M.D., M.S., of the Center for Clinical Management Research at the VA Ann Arbor Healthcare System and U-M Medical School's Division of General Medicine.

In the meantime, says Kerr, "While there are many guidelines about treating hypertension, there is an amazing lack of clarity and guidance about how many blood pressures should be taken at a clinic visit, whether those blood pressures should be averaged or whether just the lowest should be used, and how to incorporate home blood pressure readings in decisions to intensify medications. As long as this confusion exists, we may not make progress in treating hypertension."

For a complete study description and more information on findings, click here.