Hormone Replacement Therapy & Coronary Heart Disease
- Hormone replacement therapy (HRT) is a treatment used to relieve the symptoms of the menopause
- The menopause is when a female stops having periods for longer than 12 months. It's a natural part of ageing that usually happens between 45 and 55 years old
- During the menopause the ovaries have stopped releasing eggs (ovulating) and stopped producing most of their oestrogen and progesterone, this is in response to the ovaries no longer responding to FSH and LH, two hormones released from the pituitary gland in the brain
- Due to a decrease in oestrogen and progesterone there is no longer a nagative feedback loop from the ovaries to the pituitary gland and so LH and FSH levels increase
- These hormonal changes can cause many symptoms in the woman including
- Hot flushes
- Breast tenderness
- Headaches
- Sleep issues
- Emotional changes
- HRT can be given to a woman experiencing the menopause
- This replaces the hormones oestrogen and progesterone
- Oestrogen has many effects all over the body including blood vessels, bone strength, the skin, the urinary tract, the uterus and the brain
- Taking synthetic oestrogen, in the form of a tablet, patch, cream or gel, can help reduce the symptoms of the menopause
NOS: In early epidemiological studies, it was argued that women undergoing hormone replacement therapy (HRT) had reduced incidence of coronary heart disease (CHD) and this was deemed to be a cause-and-effect relationship. Later randomized controlled trials showed that use of HRT led to a small increase in the risk of CHD
- Almost 40 years ago, epidemiological observational study on the effect of HRT showed that the use of HRT led to a small decrease in the risk of developing coronary heart disease (CHD)
- Women who took HRT had a lower risk of heart disease than those that did not
- This lead to many women choosing, and being advised, to take HRT for this benefit
- The effect was deemed to be a cause-and-effect relationship
- Randomised controlled trials in the 1990s showed that the use of HRT may cause increased risk of heart disease
- New evidence suggests the “timing hypothesis” has to be considered when investigating the link between HRT and CHD
- HRT started in the early years of the menopause, does provide benefit to the heart with reduced risk of CHD
- The timing hypothesis suggests that the difference from the early observational studies and the randomised trials is because the randomised trials included many women who were several years postmenopausal, whereas the observational studies included women who were in the early menopausal years
- The correlation between HRT and decreased incidence of CHD is not actually a cause-and-effect relationship
- In general, women who take HRT are more educated, wealthier, have healthier lifestyles, and have fewer cardiovascular risk factors
- A meta-analysis study showed that the previously observed reduced risk for CHD among HRT users was decreased when analysis included socioeconomic status