Many women diagnosed with breast cancer have problems sleeping during treatment. A study found that changes in heart rate and cortisol (a steroid produced by the body) levels were linked to sleep problems in women being treated for advanced (metastatic) breast cancer.
Many things can cause sleeping problems during breast cancer diagnosis and treatment:
- daily routine changes
- treatment side effects
and can make it hard to fall asleep, stay asleep, or get quality sleep. In this small study, the researchers wanted to know if any bodily changes were happening along with the sleeping problems.
The researchers monitored the sleep quality of 99 women being treated for advanced (metastatic) breast cancer:
- total time sleeping at night
- number of times the women woke up at night
- total time in bed, whether sleeping or not
The researchers evaluated the women's psychological well-being and stress levels using psychological tests. They also monitored the women's breathing and heart rate patterns while they were asleep, as well as saliva levels of cortisol, a naturally occurring stress hormone.
- Sleeping problems were linked to a change in the normal heart rate fluctuations tied to breathing. Your heart rate usually increases and decreases as you breathe. The breathing cycle is made up of breathing in (inspiration) and breathing out (expiration). Doctors call this heart rate fluctuation sinus arrhythmia.
- Cortisol levels are usually lowest at night and highest in the morning. Women with sleeping problems had a morning cortisol level that was lower than normal.
- There wasn't a strong relationship between the women's stress levels and sleeping problems.
It's not clear whether the heart rate and cortisol level changes cause the sleep problems or if they're the result of the sleep problems. These heart rate and cortisol level changes also could be a side effect of breast cancer or treatment. Still, this study may give doctors some ideas on how to better address sleep problems that happen during treatment for breast cancer and other diseases.
If you're having troublesome sleep problems during breast cancer treatment, talk to your doctor about how you can improve the quality of your sleep. You also might want to consider a complementary and holistic medicine technique to improve your sleep. Complementary and holistic medicine techniques seek to address how disease and side effects affect your whole person: physically, emotionally, spiritually, and socially. Techniques such as yoga, hypnosis, guided imagery, meditation, and progressive muscle relaxation can improve breathing and heart rate patterns, help relieve stress, and promote better sleep. Visit the Breastcancer.org Complementary and Holistic Medicine section to learn about these and other techniques.