How BHRT Impacts Your Blood Pressure

Oestrogen, Testosterone and Blood Pressure

Hypertension or, high blood pressure is the most common condition of the circulatory system and the greatest attributor to cardiovascular disease. 2014/2015 statistics indicate that 6 million Australians suffer from elevated blood pressure, this is an alarming 34% of the Australian population. ¹

Given these staggering statistics it is important to determine what the main contributing factors to this very preventable condition are. Quite often at the AMC we hear many women suffering from elevated blood pressure with onset beginning during the perimenopause/menopausal phase. This further indicates that sex hormones have a strong influence on our cardiovascular system.

The main female sex hormone involved in regulating blood pressure is of course, oestrogen. The exact way to which oestrogen influences blood pressure is still being widely studied however, in both animal and human models, oestrogen has shown to induce vasodilation (dilate blood vessels) by increasing the amount of nitric oxide being produced and as a result, can aid in the prevention of vasoconstriction (narrowing of the arteries) which is very much correlated to elevation in blood pressure. ²

Many longitudinal studies have been conducted and have found a 4-fold increase in blood pressure during the onset of menopause. Because menopause is associated with a natural decline in oestrogen levels, it is this decline that has been in part, associated with elevation in blood pressure during this life stage. Support for this comes from observations that during the menstrual cycle, blood pressure tends to be lower during the luteal phase (when oestrogen levels are at their highest) than during the follicular phase (where oestrogen levels are at their lowest) ².

We often hear a lot of scare mongering related to oestrogen and how it is often related to an increased incidence of blood clotting and quite often, conditions related to the cardiovascular system. This is quite often correct however, it is preparation dependent.

We know that natural production of oestrogen has a positive correlation with blood pressure however, conjugated, synthetic oestrogens have been shown the opposite. A study by Wren et al. shows synthetic preparations of oestrogen have been shown to increase blood pressure in women who would have otherwise, had healthy blood pressure. 4 months after ceasing the synthetic preparations, blood pressure normalised.³

In a different randomised, controlled, cross over trial, although it only studied 30 menopausal women with mild hypertension, it indicated some promising results. The women used 100mg of transdermal (applied to skin) oestradiol and over 24 hours their blood pressure had reduced, particularly of a morning and evening. These studies need to be conducted over a larger scale to accurately determine how oestrogen truly benefits blood pressure. ⁴

Whether oestrogen influences blood pressure is very much dependant on the preparation used, the dose and how well blood pressure is managed. ²

Testosterone is another hormone that is implicated with blood pressure. We quite often only associated testosterone with libido, energy levels and men’s health however, it’s relationship with the cardiovascular system is quite important.

Testosterone deficiency has been linked to increased risks of developing high blood pressure as well as other incidences of cardiovascular disease. ⁵

Of course, hormone deficiencies aren’t the only cause of issues with blood pressure however, their important role should not be discounted either. It is always important to speak to your health professional about high blood pressure and further investigations should be promoted to rule out all possible causes.

References:

1. https://www.heartfoundation.org.au/about-us/what-we-do/heart-disease-in-australia/high-blood-pressure-statistics
2. Dubey R, Oparil S, Imthurn B, Jackson E. Sex hormones and hypertension. Cardio Res 2002;53: 688-708
3. Wren BG, Routledge DA. Blood pressure changes. Oestrogens in climacteric women. Med J Aust 1981;2:528–531.
4. Mercuro G, Zoncu S, Piano D et al. Estradiol- 17B reduces blood pressure and restores the normal amplitude of the circadian blood pressure rhythm in postmenopausal hypertension. Am J Hypertesn 1998;11:909-13
5. Kalin MF, Zumhoff B. Sex hormones and coronary artery disease: review of clinical studies. Steroids 1990;55:330–352.