New York, Sep 13 (IANS): Using hormone replacement therapy to treat common symptoms of menopause for up to five to seven years may be safe and not associated with risk of all-cause, cardiovascular or cancer death, a study with over 18 years of follow-up has found.

Hormone therapy -- which replaces the depleting levels of female hormones such as oestrogen and progesterone -- is known to be effective in reducing menopausal symptoms such as hot flashes. 

However, it has also been linked to risks including venous blood clots, stroke, and certain cancers. 

The new results showed no increase or decrease in total mortality or deaths from cardiovascular disease, cancer or other major illnesses in the randomised hormone therapy trials.

Conversely, it revealed a trend toward reduced mortality in younger women (age 50-59) who received hormone therapy, and neutral effects in older women (in their 60s and 70s) who received hormone therapy. 

"In view of the complex balance of benefits and risks of hormone therapy, the all-cause mortality outcome provides an important summary measure, representing the net effect of hormone therapy use for five to seven years on life-threatening outcomes," said JoAnn E. Manson, from the Brigham and Women's Hospital in Boston.

For the study, published by JAMA, as many as 27,347 postmenopausal women aged 50-79 years were randomly assigned to receive either a placebo, a combination of hormones (estrogen plus progestin) or estrogen alone if they had had a hysterectomy.

They were followed for 18 years and tracked for chronic diseases like cancer, as well as heart attack and deaths. The women took the hormone therapy for five to seven years.

The study results at the end of the 18-year follow-up revealed that the death rates from any cause among the women receiving some form of hormone therapy (27.1 per cent) were similar to that of women who took the placebo (27.6 per cent).