While most of us know a good night’s sleep is important for our health, a new study has pinpointed why it also could be crucial for maintaining a healthy heart.
A study by Dr Morag Young, and students Elizabeth Fletcher and Monica Kanki, shows how changes in our heart’s circadian clock, as might occur with disrupted sleep patterns, can impact the mineralocorticoid receptor (MR), a hormone receptor that regulates blood pressure. The MR is activated by the salt-retaining hormone, aldosterone, and by the stress hormone, cortisol.
While Dr Young’s previous studies have linked the MR to heart failure, this study is the first to show how disrupted circadian rhythms could combine with activation of the MR to damage our hearts.
The study has demonstrated that when our internal body clocks are in good working order, MR correctly regulates the signalling of the heart muscle cells, which control how the heart muscle works, to pump blood through the body. However, when our internal clock is unbalanced, the receptor is triggered incorrectly, which can impact heart function, potentially resulting in the development of an unhealthy heart.
Dr Young said the findings highlight the delicate relationship between circadian rhythms, hormone signalling, and heart health and blood pressure.
“Outcomes from this study will provide new knowledge into the workings of MR and circadian signalling in the heart. We know that when MR is activated inappropriately, this can lead to heart diseases. Our data suggests our body clock plays a key role in setting the scene for inappropriate MR signalling,” Dr Young said.
How prevalent is heart disease?
- Heart disease is the single leading cause of death in Australia
- It has claimed the lives of 18,590 Australians (12 per cent of deaths) in 2017
- Fifty-two Australians died daily from heart disease in 2017
The Cardiovascular Endocrinology Laboratory (as part of Elizabeth Fletcher’s PhD project and Monika Kanki’s Honours Project). Professor D. Ray from Oxford University is an expert on circadian biology and hormone signalling, and this work is a new collaboration between Dr Young and Prof Ray.
Hudson Institute communications
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