For women, the root of half our problems – cravings for chocolate, mood swings, weight gain, ability to cope with stress – seem to be driven by our wonderful female sex hormone, estrogen. Even as our supply dwindles as we age, estrogen, or rather the lack thereof, continue to plague us with new problems. An increase in weight gain, the dreaded menopause belly, high blood pressure or hypertension, heart disease, osteoporosis, and even urinary incontinence are all hormone related gifts to the post-menopausal woman. Unfortunately for women, problems such as obesity, larger than normal belly, and high blood pressure only serve to put us at an increased risk of heart disease.
Because the risk of developing high blood pressure increases after menopause, it’s generally accepted that hormones play a role in the onset of hypertension. Untreated, high blood pressure may lead to heart failure, heat attack, or stroke, any one of which could lead to a premature death. (High Blood Pressure 1)
Now, it appears that hormones may be getting a bad rap when it comes to high blood pressure. According to the results of research study conducted by the Georgetown University Medical Center (GUMC), hormones have a partner in crime when it comes to high blood pressure – your sex chromosomes. For the first time ever, researchers identified a chromosome combination that appears to indicate whether or not you’ll develop high blood pressure as you age.
Just in case you’ve forgotten freshman biology, all of us have chromosomes. A man’s chromosome combination is XY. X chromosomes are received from the mother and a Y chromosomes from the father, giving the man two sex chromosomes. Women, on the other hand, have only one sex chromosome or an XX combination, receiving an X chromosome from both mother and father. The Sry gene determines whether or not we become male or female. (Georgetown 1)
For the purpose of this study, researchers genetically engineered female mice with an XY chromosome combination. By studying the mice in tandem, that is XY female mice to XX female mice, they made a startling discovery. According to the lead investigator of the study, Kathryn Sandberg, PhD, “…XX mice have a greater magnitude of hypertension than XY mice regardless of whether they are male or female.” Sandberg is the director of the Center for the Study of Sex Differences in Health, Aging, and Disease at GUMC. (Georgetown 2)
According to Sandberg, this study is the first study of its kind to show that sex chromosomes play a separate and distinct from hormones in the development of high blood pressure. Hormones such as estrogen are still thought to play a protective role in preventing high blood pressure. Sandberg indicates that “Estrogen likely works to protect against hypertension, but once the hormone is depleted, something is unmasked on female XX chromosomes that allows blood pressure to rise." (Georgetown 3) The discovery opens the door to research for new therapies that could do more than just control high blood pressure; such treatments could treat the root cause of high blood pressure.
Sources:
High Blood Pressure (Hyptertension), The Mayo Clinic, 22 Mar 2011, http://www.mayoclinic.com/health/high-blood-pressure/DS00100/DSECTION=risk-factors
Georgetown University Medical Center (2010, March 16). Female sex chromosomes, not just hormones, help regulate blood pressure. ScienceDaily. Retrieved April 18, 2011, from http://www.sciencedaily.com¬ /releases/2010/03/100315161720.htm
Menopause: Complications, The Mayo Clinic, 23 July 2009, http://www.mayoclinic.com/health/menopause/DS00119/DSECTION=complications
Journal Reference:
Hong Ji, Wei Zheng, Xie Wu, Jun Liu, Carolyn M. Ecelbarger, Rebecca Watkins, Arthur P. Arnold, and Kathryn Sandberg. Sex Chromosome Effects Unmasked in Angiotensin II%u2013Induced Hypertension. Hypertension, 2010; DOI: 10.1161/HYPERTENSIONAHA.109.144949
Mary Kyle is a free lance writer, editor, and project manager. She has a Master’s degree in Legal Studies and is a certified Project Management Professional. She has two children’s books to her credit and has authored or co-authored hundreds of articles. A songwriter and musician, she is a member of several bands and performs regularly.