Women who receive Hormone Replacement Therapy (HRT) soon after the menopause have a much lower risk of heart attack, heart failure or dying early compared to women of the same age who do not, Danish researchers reported in the BMJ.

HRT has been a controversial subject for a number of years. There are frequent discussions and arguments regarding the advantages of HRT and its negative consequence, namely breast cancer risk.

A report published in the Journal of Family Planning and Reproductive Healthcare in January 2012 wondered how reliable the Million Women Study which linked HRT to breast cancer risk really was.

Conflicting findings from various studies have led doctors to believe that the timing after menopause is what matters when recommending HRT to their patients. The belief being that cardiovascular outcomes are influenced by how long after menopause HRT can begin.

A team of researchers from Denmark carried out a 10-year long randomized trial, with an extra six years of follow-up to determine what impact HRT might have on cardiovascular risk if it were started soon after menopause.

They recruited 1,006 women and randomly selected them into two groups:

  • The HRT group – 504 women
  • The non-HRT group – 502 women

All the women were Caucasian, recently menopausal, aged between 45 and 58 years, and healthy. The researchers only included women who had had a hysterectomy if they were aged from 45 to 52. They did not include women with uncontrolled chronic diseases, a medical history of cancer, current or previous HRT use (within the last 3 months), bone disease, drug addiction, or alcohol dependency.

The researchers used information on diagnoses or death from the Danish Civil Registration System and National Hospital Discharge Register. The primary end-point was a combo of death and hospitalization for heart failure or a heart attack.

After a decade of randomized treatment, the patients were advised to stop HRT after the results of the Women’s Health Initiative and the Million Women Study were published.

During this ten year period:

  • In the HRT Group – there were 15 deaths and 16 deaths or cardiovascular end-points
  • In the non-HRT Group – there were 26 deaths and 33 deaths or cardiovascular end-points

The team followed-up on the women for a further six years. The primary end-point was seen in:

  • 33 women in the HRT group – 27 deaths, 3 heart failures, and 3 heart attacks
    Causes of death – 6 cardiovascular deaths and 21 non-cardiovascular deaths
  • 53 women in the non-HRT group – 40 deaths, 8 heart failures, and 5 heart attacks
    Causes of death – 23 cardiovascular deaths and 17 non-cardiovascular deaths

The authors added that those who had had a hysterectomy and younger women on HRT had a considerably lower risk of death or breast cancer.

The researchers concluded:

“After 10 years of randomized treatment, women receiving hormone replacement therapy early after menopause had a significantly reduced risk of mortality, heart failure, or myocardial infarction, without any apparent increase in risk of cancer, venous thromboembolism, or stroke.”

Hormone Replacement Therapy, often referred to as HRT is given to women after the menopause when their estrogen and progesterone levels fall significantly. Progesterone and estrogen are hormones. HRT raises the levels of these hormones.

As the menopause approaches, estrogen and progesterone levels drop. Some women have HRT to reduce certain menopausal symptoms.

Estrogen stimulates the release of eggs. When a woman’s egg supply has ended, estrogen levels start to drop. Estrogen helps maintain healthy bones (good bone density), as well as skin temperature; it also regulates moisture in the vagina. When estrogen levels fall, the following symptoms are possible:

  • Fat build-up in the abdomen
  • Smaller breasts
  • Concentration and memory difficulties
  • Hot flashes (UK: hot flushes)
  • Irregular periods
  • Lower fertility
  • Moodiness
  • Night sweats
  • Sleep problems
  • Thinning hair
  • Urinary problems
  • Vaginal dryness

After several years, low estrogen levels can eventually lead to osteoporosis.

Progesterone prepares the uterus for possible pregnancies. When levels drop, women do not usually experience any immediate discomfort.

Written by Christian Nordqvist