April 4 (UPI) -- Researchers have discovered that genes associated with a body's response to relaxation techniques can lead to lower blood pressure among people with hypertension.
A study led by investigators at Beth Israel Deaconess Medical Center, Massachusetts General Hospital and the Benson-Henry Institute for Mind Body Medicine at MGH have provided insight on the molecular mechanisms by which these methods may work to lower blood pressure. Their research was published Wednesday in the Journal of Alternative and Complementary Medicine.
"To our knowledge, this is the first study to test such a mind-body intervention for a population of unmedicated adults with carefully documented, persistent hypertension, and this is the first study to identify gene expression changes specifically associated with the impact of a mind-body intervention on hypertension," Dr. Towia Libermann, director of the Genomics, Proteomics, Bioinformatic and Systems Biology Center at BIDMC said in a press release. "Our results provide new insights into how integrative medicine -- especially mind-body approaches -- influences blood pressure control at the molecular level."
High blood pressure, or hypertension, is a major risk factor for heart attack and stroke. About 1 of 3 U.S. adults -- around 75 million people -- have high blood pressure, but about 54 percent of them have it under control, according to the Centers for Disease Control and Prevention.
"Traditionally, hypertension is treated with pharmacologic therapy, but not all patients respond to drug therapy, and many experience treatment-limiting side effects," said Dr. Randall Zusman, director of the Division of Hypertension at MGH's Corrigan Minehan Heart Center and co-senior author on the new study. "In these patients, alternative strategies are invaluable. In this study, we found that the relaxation response can successfully help reduce blood pressure in hypertensive patients who are not taking medication."
The study included 58 people with an average age of 56 who had Stage 1 essential hypertension, which is a systolic blood pressure between 140-159mm Hg and diastolic between 90-104mm Hg. The participants, who were recruited from Massachusetts General Hospital's hypertension and primary-care clinics, were not taking medications to control their blood pressure or had tapered them off for five weeks before the study.
Participants attended eight weekly training sessions where they underwent mind-body interventions designed to elicit the relaxation response, including diaphragmatic breathing, mantra repetition and mindfulness meditation.
Eight weeks later, they filled out the same stress, depression and anxiety questionnaires as they did before the study.
Thirteen of the 24 participants who completed the eight-week intervention experienced a clinically relevant drop in systolic and diastolic blood pressure readings that moved participants below 140/90 mm Hg, the clinical definition of stage 1 hypertension. Their average blood pressure was 126.8/75.4, compared with 136.6/85.8 for nonresponders.
Researchers ran gene expression analyses, comparing blood samples from the two groups. They found that specific gene expression changes had occurred in the responders over the eight-week relaxation period.
They found 1,771 genes differed between the baseline blood tests and those taken after the eight weeks of relaxation response practice.
The researchers linked reduced blood pressure to immune regulatory pathways, metabolism and glucose metabolism, cardiovascular system development and circadian rhythm.
"Our results suggest that the relaxation response reduced blood pressure -- at least in part -- by altering expression of genes in a select set of biological pathways," said Dr. John Denninger, director of Research at the Benson-Henry Institute and co-first author of the study.
"Importantly, the changes in gene expression associated with this drop in blood pressure are consistent with the physical changes in blood pressure and inflammatory markers that one would anticipate and hope to observe in patients successfully treated for hypertension."