Two things you can do to lose weight and lower blood pressure
How quickly you lose weight depends a lot on your genetic makeup, but choosing a diet that also lowers blood pressure can help. So says a new study, which found that doing two things – losing weight and cutting back on salt – were more effective at lowering blood pressure than either strategy alone.
The study, published in the current issue of Hypertension, also says that genetic makeup can help determine how well your body will respond to weight loss efforts designed to control high blood pressure.
Led by researchers at The Cardiovascular Institute (part of the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School), the study may help clarify how hypertension develops and progresses in certain individuals. It may also help identify people for whom weight loss programs are most likely to help reduce blood pressure.
For the study, researchers looked at 21 polymorphisms that have been identified as having a link to hypertension, obesity, and diabetes mellitus. They wanted to see what impact weight loss and sodium-reduction programs would have on blood pressure.
Polymorphisms are the elements of DNA that differentiate one human from another, giving each individual their own unique eye color, hair texture, and even blood type.
According to the researchers, the study identified several polymorphisms related to weight sensitivity as it pertains to hypertension, shedding light on an issue that has received little attention in the past.
"There are more than a thousand papers discussing the question of what the impact is on blood pressure of decreasing the amount of salt you consume in your diet – what is called salt sensitivity. But, there is nobody talking about weight sensitivity, and weight loss is equally or more important in controlling blood pressure,” said principal investigator Dr. John B. Kostis, John G. Detwiler professor of cardiology, professor of medicine and pharmacology, associate dean for cardiovascular research, and director of The Cardiovascular Institute of Robert Wood Johnson Medical School.
"Our work describes the variability of blood pressure drop in response to weight loss, according to a number of genetic polymorphisms," added William J. Kostis, PhD, MD, clinical and research fellow in medicine, Massachusetts General Hospital, Cardiology Division, alumnus of Robert Wood Johnson Medical School, and member of The Cardiovascular Institute, who was the first author of the study.
The study involved participants between the ages of 60 and 80 who were already taking one or two anti-hypertensive medications. Each participant was randomly assigned to one of four interventions:
1) Intensive dietary intervention focused on sodium reduction;
2) Weight loss program;
3) Combination of weight loss and sodium-reduction programs; or:
4) Attention control (where individuals attended meetings that discussed dentistry, podiatry, or other topics unrelated to hypertension, weight loss, or sodium reduction).
In order to remove medication changes as a variable, the dosage of each participant’s anti-hypertensive medication remained the same throughout the intervention, regardless of which one they were assigned.
"The study showed that both weight loss, if individuals are overweight, and decreased sodium intake may each lead to lower blood pressure, and the combination of weight loss and sodium restriction is more effective than either strategy alone," said Dr. William Kostis.
According to Dr. John Kostis, physicians can put these findings to use today through a blood test or even saliva test that measures genotype. They can compare the patient's genetic background with the polymorphisms identified in the study, then counsel patients accordingly – offering advice as to which type of intervention may be more successful in lowering that patient's blood pressure, he added.
"With genomic studies becoming more widespread and less expensive, evaluating weight sensitivity may be one way to identify individuals who may benefit more from weight loss, as compared with other types of lifestyle interventions, like cutting salt from their diet," said Dr. William Kostis.
"Analysis of the polymorphisms also may give an indication of how much of a drop in blood pressure a person should expect, if he or she were to lose a given amount of weight," Dr. John Kostis added.
In addition to Dr. John Kostis and Dr. William Kostis, the research team included Nora M. Cosgrove, RN; Jerry Q. Cheng, PhD; and Yingzi Deng, MD, MS, from The Cardiovascular Institute of New Jersey, part of UMDNJ-Robert Wood Johnson Medical School. Colleagues from Rutgers, The State University of New Jersey; the Centers for Disease Control and Prevention; Tulane University School of Public Health and Tropical Medicine; Wake Forest School of Medicine; The Johns Hopkins University School of Medicine; and Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, also contributed to the study.
SOURCES: Hypertension 2013;61:857-863. Robert Wood Johnson Medical School (2013, April 25). New study confirms link between weight loss and blood pressure for individuals with specific genetic polymorphisms.