Women who begin their meno- pause earlier have a greater risk of being taken to hospital with heart failure, researchers have found.

The new study also revealed that women who have never given birth have more than a twofold increase in the risk of a common type of the condition - diastolic heart failure - compared with women who had children.

The authors said the study highlights the importance of looking at how factors such as pregnancy and reproductive period are related to cardiovascular health.

A co-author of the US-based study, Dr Nisha Parikh from the University of California, San Francisco, said: "Those are actually factors that can influence a woman's risk of cardiovascular disease, including congestive heart failure."

Writing in the Journal Of The American College Of Cardiology, Dr Parikh and the team from seven American institutions described how they analysed data on 28,516 women to explore the link between heart failure and various reproductive factors.

The data was collected through a US study known as the Women's Health Initiative, with the women beginning the study between 1993 and 1998, with an average age of just under 63 years.

The average age of menopause was 47 years and the women were followed up for an average of just over 13 years. Overall, 1,494 of the participants were taken to hospital with heart failure.

Once various factors - age, education level, smoking, body mass index, use of oral contraceptives and hysterectomy - were taken into account, the team found that earlier onset of menopause, and hence a shorter reproductive duration, was linked to an increased risk of heart failure.

For every year later that a woman experienced menopause, the team found she had a 1 per cent decrease in the risk of heart failure. Further analysis showed that the link appeared to be concentrated among women who began menopause naturally, rather than as a result of surgical procedures.

The authors said previous research had suggested the increased cardiovascular health disease risk with early menopause could, in part, be related to lower lifetime exposure to sex hormones such as oestrogen.

The latest study found that women who had never given birth were 2.75 times more likely to have diastolic heart failure than women who had children.

While the researchers found no sign that infertility was behind the increased risk, Dr Parikh said that association cannot be ruled out.

She said conditions such as polycystic ovary syndrome that can lead to infertility have also been linked to an increased risk of cardiovascular disease.

She added that other factors may also be contributing to the link. "It could be lifestyle factors at play. Of course, many women choose not to get pregnant and we don't know what could be at play there as well."

The team said the study did not explore the influence of pregnancy complications, such as pre-eclampsia and pregnancy-related high blood pressure, on the risk of heart failure.

Mr Henry Boardman of the cardiovascular clinical research facility at the University of Oxford said that while the absolute risk of heart failure is small, the study showed that pregnancy and reproductive health are relevant to cardiovascular health.

He said: "Women who have premature menopause should have a conversation with their GP about their cardiovascular risk factors."

THE GUARDIAN