"I Keep Waking Up at Dawn" ... If You Wake Up at Night Sweating and With a Racing Heart, Check Your Blood Sugar [Doctor Talk]

[Financial News] People often assume that waking up frequently at night is simply a sign of insomnia or poor sleep habits. But for people with diabetes, a specialist has warned that if they keep waking up at the same time each night, it may be worth checking for changes in blood sugar rather than dismissing it as ordinary insomnia. Nighttime hypoglycemia or hyperglycemia can disrupt sleep.
Ahn Cheol-woo, a professor of endocrinology at Gangnam Severance Hospital, said on his YouTube channel, 'Ahn Cheol-woo's Hormone TV,' that people with diabetes should suspect a diabetes-related sleep problem if they do not wake up randomly, but instead repeatedly wake up at the same time each night.
On the 27th, we asked him directly about the relationship between insomnia and blood sugar that he discussed in the video.

What stands out is that both hypoglycemia, when blood sugar drops too low, and hyperglycemia, when it rises too high, can interfere with sleep. But there are differences.
According to Ahn, hyperglycemia is the more common cause of nighttime awakenings. High blood sugar can cause intense thirst and increased urination, which may wake people so they can drink water or use the bathroom. If you wake up feeling very thirsty or with a dry mouth, it may also mean your blood sugar has risen sharply and caused dehydration.
Nighttime hypoglycemia, on the other hand, should be considered together with the timing of symptoms. Ahn explained that low blood sugar can often occur around 2 to 4 a.m. and may be accompanied by cold sweats, palpitations, and anxiety.
Nighttime hypoglycemia deserves extra attention because it happens while a person is asleep. If you are awake, you can recognize the symptoms and respond, but during sleep you may not notice them at all.


There is another reason to pay attention to nighttime blood sugar. Fluctuations during the night can affect morning glucose levels.
That is known as rebound hyperglycemia. It refers to a sharp rise in morning blood sugar after hypoglycemia occurs during sleep, when glucose falls below 70 mg/dL. In response to the danger of low blood sugar, the body releases hormones such as glucagon, cortisol, and adrenaline to raise glucose levels.
Ahn warned that if someone does not realize they had low blood sugar overnight and only sees a high reading in the morning, they may respond incorrectly by increasing evening insulin or medication.
That is why it is important not to judge based only on morning glucose readings, but to look at overnight trends as well. Ahn said a continuous glucose monitor can help provide a fuller picture of blood sugar changes during the night.
Sleep quality also matters. Blood sugar and sleep do not have a one-way relationship, with one simply affecting the other.
Ahn explained, 'What matters is not simply whether you slept for six or seven hours. What matters is how much deep sleep you got and whether your sleep was repeatedly interrupted.'
During sleep, people may experience 'micro-arousals' without fully realizing they have woken up. In the video, he said these brief awakenings can activate the sympathetic nervous system and destabilize blood sugar, creating a vicious cycle in which blood sugar changes then disrupt sleep again.
In actual practice, Ahn said he sometimes sees patients whose fasting blood sugar is higher the next day after saying, 'I slept poorly last night.' In particular, fasting glucose is influenced more by sleep and stress, while post-meal glucose is affected more by meals and exercise.

Not every case of waking up at night is a blood sugar problem. Reduced kidney function, bladder problems caused by diabetic autonomic neuropathy, enlarged prostate in men, and sleep apnea can also cause frequent nighttime awakenings. So what symptoms should make people suspect a blood sugar issue?Q. Among the many reasons for waking up at night, what symptoms suggest a blood sugar problem, and how often should they occur before getting tested?A. If you wake up about twice during sleep in a day, or more than three times a week, and this is repeatedly accompanied by cold sweats, palpitations, thirst, or frequent urination, it is worth checking for abnormal blood sugar. The key is not only actual hypoglycemia, but relative hypoglycemia. Even if the absolute number does not meet the standard definition of hypoglycemia, the body can react when blood sugar drops sharply, such as when it falls by more than 50% from your usual level.Q. If someone has not been diagnosed with diabetes but repeatedly wakes up at night or experiences cold sweats, palpitations, or thirst at dawn, should they suspect abnormal blood sugar?A. Relative hypoglycemia or blood sugar spikes, even without true hypoglycemia, should also be considered. Blood sugar spikes are now widely used to explain things like post-meal drowsiness, but if they happen repeatedly, they can be seen as a sign that the body is moving toward a metabolic disorder such as diabetes. Just as small waves can become a tsunami, frequent blood sugar spikes can lead to blood sugar problems.Q. What should you do if you recognize hypoglycemia at dawn?A. Nighttime hypoglycemia is hard to notice because it happens while you are asleep, so setting alarms on a continuous glucose monitor (CGM) can help. If low blood sugar is confirmed, it is better to first consume something that can be absorbed quickly, such as a sugary drink, rather than chocolate. Ultimately, it is important to start eating to stabilize blood sugar.Q. Some diabetes patients think frequent nighttime awakenings are just insomnia and look for sleeping pills or sleep aids first.A. Metabolic insomnia caused by blood sugar problems can sometimes improve once the underlying metabolic issue is addressed. So rather than immediately turning to sleeping pills, it is important to first check whether there is a metabolic cause, including blood sugar issues. If needed, hormone therapy such as melatonin can also be considered.

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