How Hot Flashes in Women Protects Against Heart Disease
Posted Feb 26 2011 10:32am
Hot flashes and night sweats are common symptoms of menopause. Interestingly, in a study of 60,000 post-menopausal women, those that suffered the worst night sweats and hot flashes at the start of menopause had a 17% lower chance of stroke and 11% lower chance of heart disease when followed for 10 years, compared with those who had no symptoms. Heart attack deaths were 24% lower. The authors could not give a clear explanation for their findings. Here’s my explanation:
I’ve written before that I often see hot flashes and night sweats in young men. They also have irritability, mood swings and insomnia. These symptoms are neurologic events that occur due to a relative change in the status of the involuntary nervous system. These young men are typically gaining weight quickly. This causes a rapid relative change in their sleep-breathing status, due to more frequent breathing pauses at night. Rapid weight gain is known to contribute to obstructive sleep apnea.
In menopausal women, not only do most gain some amount of weight, their progesterone levels begin to drop in their early 40s. Progesterone is a known upper airway muscle dilator, increasing muscle tone to the tongue. As progesterone slowly drops, the tongue relaxes more, especially when in deep sleep. This causes more frequent micro-obstructions and arousals, leading to the typical neurologic (vasomotor) symptoms commonly seen in perimenopausal women. It’s this relative change in the sleep-breathing status that irritates the involuntary nervous system (which regulates temperature, sweating, heart rate, blood pressure, digestion, and various other body functions).
Dr. Guilleminault of Stanford University states that people with obstructive sleep apnea have diminished nervous systems in the throat. Vibrations from snoring or reflux from obstructive events can damage the protective pressure and chemical sensors in the throat. If you already have some degree of obstructive sleep apnea as you approach menopause, it’s plausible that as progesterone levels drop, the additional breathing pauses don’t have as much of an effect on the involuntary nervous system, since it’s been happening already for years or decades. If your nervous system is intact, then the sudden increases in breathing pauses can lead to more severe vasomotor symptoms.
What this study suggests is that the more you’re susceptible to obstructive sleep apnea, the less likely you’ll suffer hot flashes and night sweats early in menopause. This can explain the higher rate of cardiovascular disease in post-menopausal women.
This is another example of interpreting scientific studies based on my sleep-breathing paradigm. If you’re not familiar with this concept, you can read my articles, or for a more in-depth explanation, take a look at my book, Sleep, Interrupted.
What do you think about my line of reasoning? Please enter your feedback below in the comments box.