Are there sex differences in risk factors for incident myocardial infarction (MI) and do they vary with age? It appears that the answer is yes.

Women who smoke, have diabetes or high blood pressure increase their risk of a heart attack more than men faced with the same risks= This is the main conclusion of a large study of UK adults.

Results were presented in the British Medical Journal

471 998 people participated in the study. 56% were women (mean age 56.2) with no history of cardiovascular disease.

Over seven years, 5,081 people had their first heart attack and one in three of them were women.

Risk factors more important for women

Although the risk of having a heart attack is lower in women than in men of all ages, certain risk factors appeared to have a greater impact on women, researchers claim:

• Women who smoked were three times more likely to have a heart attack than women who did not smoke - but in men, smoking only doubled their risk.
• High blood pressure increased a woman's risk by an extra 83% relative to its effect in a man.
• Type 1 and type 2 diabetes both had a greater impact on the heart attack risk of women compared to men, the study found.

Possible explanations

The researchers say they do not know why these factors are sex-specific, and no firm conclusions can be drawn about cause and effect.

Heart disease also affects women and this needs to be recognised. It's a complicated, long-term thing to work out, probably caused by a combination of factors - both biological and social," commented to BBC Dr Elizabeth Millett, lead study author and an epidemiologist at the George Institute for Global Health, University of Oxford.

Biological factors may be a reason. For example, type 2 diabetes, which is usually linked to poor diet and lifestyle factors, may have a different impact on the female heart to the male one.

Read the whole study HERE