Obesity Surgery May Cut Blood Pressure
Benefits Seen in Very Obese Patients After Gastric Bypass Surgery
March 20, 2006 -- Obesity surgery might help get high blood pressure under
The finding comes from John Fernstrom, PhD, and colleagues of the University
of Pittsburgh's medical school.
They report that among very obese people, blood pressure often dipped after
weight loss surgery, especially for people with previously untreated high blood
The results could help show which patients "are likely to experience
substantial improvements in blood pressure" after gastric bypass surgery
and possibly no longer need medicine to control blood pressure, Fernstrom says
in a news release.
Fernstrom's study appears in the Archives of Surgery. It comes on the heels
of a report by other researchers showing that weight loss surgery
may help avoid heart disease and stroke.
Before and After Surgery
Fernstrom's team checked the medical records of 347 people who got weight
The patients were "very obese" before surgery, with an average BMI
(body mass index) of 50-55, the researchers write. A BMI of 30 or more is
considered obese. Being overweight or obese can boost blood pressure, the
Before gastric bypass surgery, 192 patients had high blood pressure. Of
those patients, 103 were taking prescription drugs to control their blood
pressure. High blood pressure was defined as a reading of 140 or higher for
systolic pressure (top number), 90 or higher of diastolic pressure (bottom
number), or both.
Average BMI fell to 35 during the first 12-18 months after surgery. That's a
big drop, but a BMI of 35 is still obese, Fernstrom and colleagues note.
After surgery, 92 patients still had high blood pressure, with 68 taking
blood pressure medicines. Of the 103 patients taking blood pressure drugs
before surgery, 35 stopped taking those drugs in the months after surgery, the
The biggest blood pressure improvements were seen in patients who had had
untreated high blood pressure before surgery, write Fernstrom and
Patients with normal blood pressure and those already being treated for high
blood pressure had less room for improvement. Diastolic blood pressure improved
more than systolic blood pressure.
The researchers checked the patients' medical charts for nearly two years
after surgery. It's not yet clear if the patients' BMI and blood pressure
improvements lasted longer than that, the researchers note.
The patients' medical charts don't track changes in the patients' eating
habits or physical activity, which may also affect blood pressure.