Treating high blood pressure for those with diabetes: Finding the right balance
Blood pressure is the force of blood against the walls of arteries. A person's blood pressure rises and falls throughout the day. When blood pressure
remains elevated over time, it's called high blood pressure, or hypertension. High blood pressure is dangerous because it makes the heart work too hard. It
increases the risk of heart disease and stroke, and can result in other conditions such as congestive heart failure, kidney disease, and blindness.
A study published May 28, 2012, in the Archives of Internal Medicine i by a team of researchers
from VA's Ann Arbor Healthcare System and the University of Michigan Health System indicates that VA has been remarkably successful at reducing the level
of blood pressure for the Department's patients with diabetes—but also that some diabetes patients may actually have had their blood pressure get too low.
"Appropriately treating blood pressure (BP) in people with diabetes is extremely important," says Eve Kerr, MD, MPH, the study's lead author and director
of the Center for Clinical Management Research at Ann Arbor, and professor of internal medicine at the University of Michigan Medical School. "Good blood
pressure control should still be the goal to reduce risk of heart attack, stroke, and other conditions."
The study looked at the electronic health records of 977,000 VA patients nationwide treated for diabetes at 879 VA hospitals and clinics during 2009 and
2010. The team found that a remarkable 94 percent of all VA diabetes patients were having their blood pressure appropriately managed.
Blood pressure was controlled in 82 percent of the patients whose records were reviewed by the study team. At present, VA defines controlled blood pressure
for its patients as a systolic pressure (pressure within the arteries when the heart muscle is contracting) under 140 and a diastolic pressure (pressure
when the heart is resting) under 90.
Despite this good news, Kerr and her colleagues warned that the picture was more complicated than it appeared. "Just treating to a BP target in all
patients may result in over-treating and harming some patients because their blood pressures actually fall too low," she says. "We need to find better ways
to make sure that patients who need aggressive treatment are getting it, and to decrease the rate of inappropriate overtreatment."
In looking at patients' records, the team developed a "clinical action measure," or a way of assessing the appropriateness of a patient's care by looking
at treatment factors and contraindications, not just the patient's blood pressures. They also defined a monitor of potential overtreatment, to signal that
some patients could be receiving overly aggressive treatment.
According to a University of Michigan press release on the study, recent research has found that patients with diabetes don't have better cardiovascular
outcomes, but experience more side effects, if they get aggressive treatment to lower their blood pressure below 130/80. At the same time, some people
experience side effects caused by "polypharmacy," or the impact of taking multiple drugs at the same time for the same condition. Also, diastolic blood
pressure under 65 is associated with worse cardiovascular health, and low blood pressure could also cause dizziness that can lead to dangerous falls.
A seven-and-a-half-year-long research effort by VA's Cooperative Studies Program, called the VA Diabetes Trial (VADT), looked at nearly 1800 patients who
had difficulty controlling the levels of glucose in their blood and did not respond to the usual treatments for the illness, which include insulin use and
other medication, blood pressure and cholesterol control, meal planning and weight control, education, exercise, and foot care.
Among the study's many findings was a recommendation that while it is urgent to treat diabetic patients with systolic blood pressure readings above 140mm,
diabetes patients should not try to reduce their diastolic pressure below 70mm, because that level of low blood pressure was associated with a higher risk
of cardiovascular disease.ii
VADT was co-chaired by William C. Duckworth, MD, director of diabetes research at the Phoenix VA Medical Center and professor of clinical medicine at the
University of Arizona, and Carlos Abraira, MD, a physician-researcher at the Miami VA Medical Center and professor of medicine at the University of Miami
Miller School of Medicine.
In their study, Kerr and her team found that eight percent of VA patients had been treated so effectively that their blood pressure was now significantly below the target rate—low enough that health issues related to hypotension (low blood pressure) might occur.
They argue that merely reducing blood pressure for patients across the board was a good idea when blood pressure control at VA facilities was
inconsistent—but now that VA has done so well in lowering people's pressure, a more sophisticated approach is needed.
"We need to have performance measures that focus on appropriate treatment, and if patients are being treated aggressively but still don't get to a target
control value, we need to allow that to count as appropriate care," she says. The team recommends VA look at the individual patient in deciding whether
blood pressure control is appropriate in that patient's case, and not use the same measure for everyone.
The study concludes, "Implementing a clinical action measure for hypertension management, as the Veterans Health Administration is planning to do, may
result in more appropriate care and less overtreatment."
Kerr urges all patients with diabetes to talk regularly to their primary care physicians about their blood pressure treatment and the lifestyle steps and
medicines they are taking to keep it under control. "It is essential," she says, "that we continue to monitor and focus on BP control among patients with
diabetes, but we also have to realize that when BP starts to dip too low, it may be time to decrease treatment."
VA believes it is essential to screen and treat its Veteran patients for elevated blood pressure, because it is an important precursor to hypertension and
a major factor for illnesses and death related to the heart. To successfully keep their patients' blood pressure at healthy levels, VA physicians work with
them to manage hypertension by using a combination of lifestyle modifications (including maintaining a healthy weight, increasing physical activity,
reducing salt intake, drinking only in moderation, and eating healthy foods) and prescription drugs, where necessary.
i EA Kerr, MA Lucatorto, R Holleman, MM Hogan, ML Klamerus, TP Hofer, and the VA Diabetes QUERI Workgroup on Clinical Action Measures, "Monitoring
Performance for Blood Pressure Among Patients With Diabetes Mellitus: Too Much of A Good Thing?", Arch Intern Med, 2012 May 28:1-8.
Doi:10.1001/archinternmed.2012.2253. (Epub ahead of print.)
ii RJ Anderson, GD Bahn, TE Moritz, D Kaufman, C Abraira, W Duckworth, "Blood Pressure and Cardiovascular Disease Risk in the Veterans Affairs
Diabetes Trial," Diabetes Care January 2011 34:34-38.