Female Healthy Heart Advantage

Tami Martino and research team from the University of Guelph may have solved the biological reasons why heart disease develops later in women than men. A first ever study suggests females have a healthier heart and that it is linked to the ovarian hormones. Interplay between ovarian hormones and circadian ‘clock’ molecules protects the heart until menopause according to the study. The findings by have been published in Cardiovascular Research that could help prevent heart disease as we all grow older.

The team in earlier studies the team found heart attacks were worse for males than females of similar age groups, and discovered a time effect, that males had more severe heart attacks while sleeping. This led to the theory of circadian mechanism operating differently between the sexes. To test this theory they did a study on older mice with a genetic ‘clock’ mutation that desynchronizes the circadian mechanism. Aging male mice developed heart disease but not female. The team of Marcia Bakovic, Elena Choleris, Faisal Alibhai, and Martino discovered female heart cells are different than those in males.

Cardiolipins in clock male mice hearts are similar to those in humans with heart disease, which also had worse glucose, energy, and cardiac profiles. The female clock hearts had healthy cardiolipin profile as well as better energy. The advantage for clock females was no longer there when they had their ovaries removed, the clear sign hormones such as estrogen protected the heart even with the circadian mechanism disturbed. Circadian rhythm is important to maintain to achieve longer and healthier lives. The study findings may lead to benefits for both sexes.