HRT and stroke: Is there a risk?

HRT and stroke: Is there a risk?...

"Menopause can have a significant effect on a woman's ability to live life to the full. The benefits of Hormone Replacement Therapy (HRT) in relieving some symptoms are well documented. But there are some potential risks - including stroke. However there are a number of everyday healthy choices you can make to reduce this risk, such as quitting smoking, eating well and daily exercise. Talk to your GP about your personal health risks." Dr Christine Bennett, MBF's Chief Medical Officer.

What is stroke?

Stroke, sometimes called an ‘attack on the brain', is a medical emergency and occurs when the blood supply to the brain is disrupted. It may be the result of a blockage from a blood clot or fatty plaque (ischaemic stroke) or a ruptured artery (haemorrhagic stroke).

When the blood to the brain is stopped, the surrounding part of the brain is deprived of oxygen and brain cells die or become permanently damaged very quickly - within a few minutes to hours.

Depending on the size and location of the damaged artery, the effects of a stroke can vary. The ability to move arms, legs or face may be affected, difficulties with speech or vision can occur, feeling in parts of the body on one side may be altered and headache or disorientation are other symptoms.

A mini-stroke, sometimes called a "TIA", is short lived and is due to a temporary blockage in an artery. It can serve as a warning that you could be at increased risk of a stroke in the future.

General statistics

60,000 Australians will suffer a stroke in 2008 ¹
Stroke is the 2 nd highest cause of death in Australia after coronary artery disease ²
Stroke costs the nation an estimated $2.14 billion a year ³

What are the risk factors for stroke?

As you get older, the risk of having a stroke increases. Stroke is more common in men but it kills more women. This is because women are more likely to delay seeking treatment for stroke as their symptoms may be different to men.

Other risk factors for stroke include high blood pressure, high cholesterol, smoking, migraine, family history of stroke or blood clotting disorder, irregular heart beat (in particular atrial fibrillation), obesity, diabetes, poor diet and inadequate exercise.

Recent studies have indicated that postmenopausal hormone replacement therapy (HRT) may be an additional risk factor for women.

What is HRT?

Menopause occurs when a woman stops ovulating, the ovaries stop producing oestrogen and her monthly period stops. HRT (hormone replacement therapy) is a combination of oestrogen and progesterone or oestrogen alone prescribed to women following menopause to reduce unpleasant symptoms. These may include:

hot flushes
night sweats
dry skin or vagina
vaginal and bladder symptoms
insomnia
cognitive disturbances such as memory loss
reduced libido
mood swings
prickly skin
hair loss or abnormal growth
dry, itchy eyes
tooth loss
gum problems.

While HRT reduces the risk of osteoporosis and bowel cancer, it increases the risk of others.

Research has shown that if HRT is used for more than 5 years there may be an increased risk of cardiovascular disease, stroke and breast cancer. ⁴

Does HRT have any side effects?

Some women experience side effects when using HRT, particularly when treatment is first started. These may include:

breakthrough bleeding
breast tenderness
bloating
blood clots

Research has shown that HRT does not make women gain weight. If they are prone to do so they will gain weight regardless of whether they take HRT.⁵

What are the risks of HRT?

The risks of HRT in postmenopausal women are minimal if used in the lowest possible doses for less than five years as close to the menopause as possible and up to age 60. The risks for combined oestrogen and progesterone HRT, however, can include breast cancer, stroke, cardiovascular disease and blood clots. 4,6,7 Oral oestrogen alone can increase the risk of uterine cancer.

What is the risk of stroke from HRT?

Women may be at increased risk of stroke from HRT if:

They start HRT at a young age (under 50)
They start more than 10 years after the menopause
They have higher doses of HRT
They take it for more than 5 years. ⁶

What is the risk of stroke from the contraceptive pill?

The Melbourne Risk Factor Study Group indicated that there was no increased risk of stroke in women taking a low dose (<50ug) of oestrogen, provided that they did not smoke, have diabetes, hypertension or a family history of stroke. ⁶

What is the risk of stroke from smoking?

Smoking 20 cigarettes a day doubles your risk of suffering a stroke. 6 The good news is that if you quit smoking, within 5-15 years your stroke risk reverts to that of a non-smoker.

Why is stroke a risk of HRT/contraception?

High doses of oestrogen in some oral contraceptive pills and in some forms of HRT affect the blood's clotting factors making clot formation more likely. This can increase the risk of stroke. The risk is reduced if the dose of oestrogen is as low as possible and HRT is taken for less than five years.

What is the difference in symptoms between male and female?

Classic stroke symptoms that occur in both men and women include:

Sudden numbness, weakness or paralysis of the face, arm or leg, usually on one side of the body.
Sudden difficulty speaking or understanding speech
Sudden blurred, double or reduced areas of vision
Sudden dizziness, loss of balance or co-ordination
Sudden severe or unusual headache
Confusion or problems with memory, spatial orientation or perception (source mayo clinic)

However, women may have a different cluster of symptoms to men that may cause them to be overlooked as an emergency when attending a medical facility. The symptoms can include:

Loss of consciousness or fainting
Shortness of breath
Falls or accidents
Sudden pain in the face, chest, legs or arms
Seizure
Hiccups
Sudden nausea
Sudden fatigue
Sudden palpitations (racing or pounding heart)

Is there a gender difference in the recovery from stroke between men and women?

Women have been shown to have a poorer recovery from stroke compared to men. More women than men die after a stroke and female stroke survivors have lower functional recovery and poorer quality of life 3 months post discharge. The differences were not explained by the later onset of presentation and treatment generally in women.⁹

What should you do if you think someone is having a stroke?

If you suspect that someone is having a stroke, don't hesitate to act and seek help. Urgent treatment in hospital and preferably a specialised stroke unit within 6 hours is necessary to minimise the chance of permanent brain damage.

Stroke is a medical emergency and "000" should be called. The acronym "FAST" is used to promote what you should do in a medical emergency: ¹

F -face-does one side droop when asked to smile?

A -arms-when raising one arm does one drift down or not move?

S -speech-when trying to repeat a simple sentence are the words slurred or incorrect?

T- time- act fast, ring 000 and rush to hospital

Can stroke be prevented?

There are healthy choices that can be made everyday to help reduce the risk of stroke. ¹⁰

Diet: a diet rich in fruit and vegetables which contain antioxidants to prevent atherosclerosis, unsaturated (found in nuts, seeds and oily fish) fats and fibre can help reduce the risk of stroke. It has been estimated that consuming one to two servings more of fruit and vegetables a day can reduce the risk of stroke by up to 40 per cent.

A diet high in salt and saturated fats (found in animal fats such as red meat, cheese and butter) can increase the risk of stroke.

Exercise: Regular physical activity helps improve the condition of the heart, enhances circulation, lowers blood pressure and cholesterol levels, and helps to keep weight down, helping reduce the risk of stroke.

Aerobic exercise that increases your heart rate and makes you sweat is important. Even small amounts of exercise such as walking to the shops, using the stairs instead of the lift, getting off the bus a stop earlier and going for a longer brisk walk at weekends can all improve your aerobic capacity. Check with your GP before you start any exercise program. Aim to do at least 30 minutes of moderate exercise most days of the week. If you feel dizzy or unwell, stop the exercise and talk to your GP.

Lifestyle: Other ways to reduce your risk of stroke include:
- Limit consumption of alcohol: binge drinking in particular increases the risk of stroke.
- Know what drugs you're taking . Some medications such as HRT and the contraceptive pill can increase your risk of stroke. Talk to your GP.
- Being overweight .
- Stop smoking . Getting help to quit significantly increases your chances of quitting successfully. Talk to your GP or call the Quit line on 13QUIT.
- Reduce stress . Making time for rest and relaxation is good for you. Get plenty of sleep.
- Medication . Drugs, such as aspirin, may be recommended to prevent stroke in those thought to be at risk.

Sources:

1. National Stroke Foundation of Australia (www.strokefoundation.com.au)

2. Causes of Death 2006, Australian Bureau of Statistics

3. Australian Institute of Health and Welfare ( www.aihw.gov.au)

4. Womens Health Initiative Study 1991 – 2002

5. Better Health Channel, Victorian Government (www.betterhealth.vic.gov.au)

6. Grodstein et al. HRT increases stroke risk, Archives Internal Medicine, vol 8, April 2008

7. Quitline (www.quitnow.info.au)

8. University of Sydney (www.health.usyd.edu.au/hrt)

9. Mayo Clinic (www.mayoclinic/womenshealth.com)

10. BBC (www.bbc.co.uk)