Gender differences

“I was so surprised to learn during your presentation yesterday that women’s outcomes are worse than men’s following a heart attack.”

When it comes to heart disease, we know that women are not just small men. Yet many of our current diagnostic tests and subsequent treatment decisions are based on cardiac research done on male subjects, or with females represented in statistically insignificant numbers. Cardiovascular disease is not alone, by the way: scientific research has historically focused on men, with two-thirds of all diseases that affect both men and women studied exclusively in men. Here are some important heart-related differences:

Women’s blood vessels are exposed to changing levels of estrogen throughout our lives, first during regular menstrual cycles, then pregnancy, and later during and after menopause as estrogen levels decline with age. Estrogen affects how blood vessels narrow and widen and how they respond to injury, so changes in our estrogen levels can mean changes in the behaviour of blood vessels.

New research from Finland suggests that women’s naturally low iron stores until menopause may actually be a protective factor in our risks for heart disease. Women’s vessels may also be ‘programmed’ for more changes than men’s vessels, which could increase the risk of having problems in the lining of the arteries (endothelium) and the smooth muscles in the walls of the arteries. Women in several studies, including the WISE study, have had evidence of damage to the smooth muscle in the small arteries.

In addition to changing hormone levels of menstruation and menopause, there are several other risk conditions for blood vessel problems that are unique to women, such as pre-eclampsia and other pregnancy complications (a condition that I had while pregnant with my first baby). Learn more at Pregnancy Complications Strongly Linked To Heart Disease.

Being appropriately diagnosed when presenting with cardiac symptoms is the key to being appropriately treated. Yet women (especially younger women) with heart disease are far more likely than men to be misdiagnosed. Research on cardiac misdiagnoses reported in the New England Journal of Medicine* looked at more than 10,000 heart patients (48% women) who had gone to their hospital Emergency Departments with chest pain or other heart attack symptoms. Women younger than 55 were seven times more likely to be misdiagnosed than men of the same age. The consequences of this were enormous: being sent away from the hospital doubled the chances of dying.

Watch these two panel discussions on “The Heart Of A Woman“ with female cardiologists for more on these gender differences, or this 2-minute video from the Mayo Women’s Heart Clinic about why women’s cardiac diagnoses lag behind men’s.

* Pope JH, Aufderheide TP, Ruthazer R, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med. 2000;342:1163-1170.

See also:

Is it gender difference or gender bias? Learn what the American Heart Association says about how women’s heart disease is diagnosed and treated compared to men.

How gender differences in heart attack treatment contribute to higher death rates for women – a report of a study in France that suggests serious discrepancies between how male and female heart patients are treated

Find out why, even though 53% of heart patients are women, only 25% are cardiac research participants.

Despite what the medical community may have believed for the past 30 years, heart disease is an equal opportunity diagnosis for both men and women. The Toronto Star explains why.

A woman’s heart weighs about 118 grams, similar to a green pepper. A man’s heart weighs at least 60 grams more, making it easier for cardiologists to work with. Find out more in this fascinating Chatelaine magazine article.

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Women & Men: Ten Differences that Make a Difference to our Overall Health

When it comes to our overall health, there are many crucial differences between men and women. Yet many of us do not know that we react differently to some medications, are more vulnerable to some diseases, and may have different symptoms than men do.

Here are 10 vital facts about sex differences in our overall health care:

Heart Disease – Heart disease kills more women than men each year – and strikes women, on average, 10 years later than men. Women are more likely than men to have a second heart attack within one year of their first. Over 40% of all deaths of Canadian women are related to cardiovascular disease. More on gender-based knowledge deficits in cardiac research.
Depression – Women are 2-3 times more likely than men to suffer from depression, in part because women’s brains produce less of the hormone serotonin.
Osteoporosis – Women comprise 80% of the population suffering from osteoporosis, attributable to women’s higher rate of lost bone mass.
Smoking – Smoking has a more negative effect on cardiovascular health in women than in men. Women are also less successful in quitting smoking and have more severe withdrawal symptoms.
STDs – Women are two times more likely than men to contract a sexually transmitted disease, and more likely to experience significant drops in body weight, which can lead to wasting syndrome.
Anaesthesia – Women tend to wake up from anaesthesia more quickly than men – an average of seven minutes for women and 11 minutes for men.
Drug reactions – Even common drugs like antihistamines and antibiotics can cause different reactions and side effects in women compared to men.
Autoimmune Disease – Three out of four people suffering from autoimmune diseases (such as multiple sclerosis, rheumatoid arthritis or lupus) are women.
Alcohol – Women produce less of the gastric enzyme that breaks down ethanol in the stomach. So after consuming the same amount of alcohol, women have higher blood alcohol content than men, even allowing for size differences.
Pain – Some pain medications (known as kappa-opiates) are far more effective in relieving pain in women than in men.