If you are regularly having high sugar levels before breakfast , there are a number of causes which could be the reason for it.
Below are some of the more common reasons, including an explanation of how they can cause high sugar levels and what action you may wish to take to tackle the problem.
For advice on how to spot high patterns, see our guide to dealing with highs and lows
- Too little intermediate or long acting (basal) insulin
- Having a meal with a delayed spike for dinner
- Unplanned snack before bed or during the night
- Having been less active than normal the day before
- Dawn phenomenon
- Somogyi effect
- If you are taking Levemir during the morning
- Too little intermediate or long acting (basal) insulin
- Having a meal with a delayed spike for dinner
- Unplanned snack before bed or during the night
- Having been less active than normal the day before
- Dawn phenomenon
- Somogyi effect
- If you are taking Levemir during the morning
- Four Reasons for Morning High Blood Sugar Levels
- One Drop Guide: Why Is My Blood Sugar High In The Morning?
- Why Is My Morning Blood Sugar so High?
- Diabetes Forecast
- Christy Parkin, MSN, RN, CDE, responds:
- How It Works
- The Overnight Blood Sugar Conundrum
- Reasons for a high fasting blood glucose value in the morning for Type 1 Diabetes
Too little intermediate or long acting (basal) insulin
If you are consistently getting high readings before breakfast, it could be that your long acting (basal) insulin is too low. If you take intermediate insulin (such as NPH insulin), consistently high sugar levels in the morning could be the result of taking too little intermediate insulin at dinner time.
Consider increasing your dose of long acting or intermediate insulin. If increasing your insulin, do so gradually and test your blood glucose regularly to identify whether your blood glucose is going to low as a result. As always, be prepared to test your blood glucose if you feel the symptoms of hypoglycemia.
If you at all unsure of how or whether to adjust your insulin, speak to your diabetes health team who will be able to help you.
Be careful if you are considering increasing insulin
Make sure your health team are happy for you to adjust your own insulin doses and consult them if you are in any doubt. If you increase your insulin, do so gradually to prevent risking severe hypoglycemia from occurring and test your sugar levels regularly to check low sugar levels are not occurring
Having a meal with a delayed spike for dinner
Some meals have a delayed spike, that is they can cause a significant rise in blood sugar levels that occurs a number of hours after having eaten.
Meals that can typically lead to a delayed increase in blood glucose levels include:
- High protein content
- Pizza, pastry or other foods with a high fat content
When having these kinds of meals, aim to take a blood test 5 or 6 hours after eating.
You may need to wake during the night to take the test. If blood glucose levels are high, you may need to take an extra dose of insulin after having eaten these meals.
Consult your health team for advice on managing the insulin for these meals.
Unplanned snack before bed or during the night
High sugar levels in the morning may also result if you have had an unplanned snack before bed or during the night This could also include if you have had a larger snack than usual before bed.
Aim to avoid having unplanned snacks. Unplanned snacks can sometimes be the result of having higher too high or too low sugar levels, so bear this in mind. Another possible reason is if you have been having light dinners that may not be keeping you satisfied.
If you are not testing before snacking, you may find it helpful to test before you snack to see if the urge is related to high or low sugar levels.
Having been less active than normal the day before
If you are usually quite active during the day then having a day with significantly less activity than normal could result in higher blood glucose levels through the through the following night.
Try to include more activity into your less active days where possible. If this is not possible, consider slightly increasing your long term or intermediate insulin after a less active day.
The dawn phenomenon describes an effect in which the liver releases glucose into the blood to prepare the body for waking. The American Diabetes Association states that the hormones responsible for dawn phenomenon tend to occur between 4 and 5am.
To test for the presence of dawn phenomeno, wake up to take a blood glucose test between 3 and 4am and again after waking.
If your blood glucose has risen considerably between the two tests, it could be the result of dawn phenomenon.
Note that another possible cause for a rise in blood glucose levels can be if you take Levemir injections in the morning. See lower down this page for more information.
The Somogyi effect describes a possible over-reaction of the body to correct hypos during the night.
There is some doubt as to the validity of the Somogyi phenomenon but research has yet to conclusively either confirm or disprove the effect.
To test for the possibility of the Somogyi phenomenon occurring, test your blood glucose at 3am to see whether nocturnal hypoglycemia is occurring.
If you are getting low blood glucose levels during the night, treat the hypo and re-test when waking. Night time hypos can be prevented either by taking a carbohydrate based snack before bed, or by decreasing your long term insulin.
If you take intermediate insulin at dinner, decreasing this dose will reduce the likelihood of nocturnal hypos.
If you reduce your long term insulin or intermediate insulin, test your blood glucose through the day to see if your sugar levels are going higher at other points of the day. If this is the case, you may need to adjust one or more other doses.
If you are taking Levemir during the morning
Levemir is a long acting insulin that has duration of between 18 and 24 hours.
If you take Levemir in the morning, this can mean that the effects of the insulin can wear off during the night.
This may also be the case, albeit to a lesser extent, if you are on a split dose of Levemir, that is taking an injection during the evening and an additional dose at breakfast.
If you think the duration of Levemir could be influencing higher breakfast blood glucose readings, speak to your diabetes health team who will be able to advise you on the best action to take.
Four Reasons for Morning High Blood Sugar Levels
Q: Dr. Stanislaw, why do I go to bed with a good blood sugar reading, but then wake up and it’s too high?
A: There are 4 reasons for unexplained high morning blood sugar levels.
Having a thorough knowledge of why blood sugar levels do what they do is an essential, yet often lacking, piece to good diabetes care. Morning blood sugars can be especially hard to understand. You go to bed and your blood sugar level is perfect….Ahhh. Then you wake up and it’s awful?! What happened??
I’ve had type 1 since I was seven years old. When I was diagnosed in 1980, blood glucose testing didn’t even exist. I had to pee in a cup twice a day and test how much sugar was in it, which only told me if I had been high over the past few hours. There was no way to ever know what my glucose level was in the moment…we’ve come a long way!
Being able to know what your glucose level is at any time is a fabulous advancement that allows you to have better care. But more information can lead to new frustrations. Back then, if I woke up and didn’t feel low, all was good. Today, we can know exactly where our level is at anytime and if it’s in good range we’re happy and smiling! But if it’s not, we’re likely frowning and not feeling so hot.
So let’s take a look at four reasons why blood sugar can be high in the morning:
1.) Your BACKGROUND MEDICATION is set too low.
A perfectly set regimen of oral blood sugar management medications and/or basal/long-acting insulin dose should keep your blood sugar normal throughout the night and allow you to wake up with a normal blood sugar level. However many people with diabetes are not on adequate oral meds and/or do not have a properly set basal insulin dose to allow this to happen. I help my patients figure this out via planning a specific type of dinner at a particular time, and then doing multiple testing throughout the night over two to three nights. We watch what the blood sugar does throughout the night and adjust the medications until the blood sugar stays in normal range throughout the night, waking up with 70 – 90mg/dL as the ideal goal. It takes working with a knowledgeable provider, plus time and patience to get this set right.
If we know medications and/or the long-acting/basal insulin is set right and you’re still waking up high, then it is likely one of the next three scenarios:
2.) DINNER took longer to digest than expected.
Just because you go to bed with a great blood sugar level does not mean it’s going to stay that way. Depending on what you had for dinner, especially if it was large, and/or contained a mix of high carb and fat and/or protein, digestion can take 4-8 or even more hours. (This is especially true for those with gastroparesis, which can occur from years of high blood sugars damaging the nerves to the digestive system.)
So when you go to bed, if your dinner hasn’t completely digested, your blood sugar level will continue to go up for many more hours…even beyond the time your fast-acting insulin finishes working.
I help my patients try different dinners, until we dial in waking up with a good glucose level. Sometimes we find the answer, but sometimes we don’t. If so, you’ve got to keep looking…
3.) Your HORMONES spiked in the early morning hours, making your liver dump glucose into your blood.
Even if you don’t eat, your body can raise blood sugar on it’s own. One of those ways is via the natural cycle of hormones that tend to peak in the morning.
The hormone cortisol peaks around 8am and has the effect of raising blood sugar.
Furthermore, this can be accompanied by what is called the ‘Dawn Phenomenon,’ which refers to the daily morning activity of the liver clearing out insulin from the blood, having the effect of raising blood sugar levels.
This can be frustrating to say the least! I understand. I can help you figure out if this is what is going on via setting you up on a plan that includes testing at specific times throughout the night.
4.) You’re REBOUNDING from a low.
Your body doesn’t like to go low, so after an intense low, the body can actually rebound and make you go high afterwards.
The only way to see if this is happening is to monitor your sugar level every few hours through the night.
Understanding these four scenarios is essential for waking up with a good glucose level. Consistently starting your morning in the normal range IS possible. Trust me, it CAN be done.
The tips I just gave you I’d have paid thousands of dollars for when I was young because it would’ve saved me years of frustration with trying to figure all of this out on my own!
Do you have questions? I’d love to help. Let’s chat. I make time in my schedule, when I can, to connect with others because talking one diabetic to another can be life changing. My specialty is Type 1 but I help Type 2’s as well.
If you need help with how to wake up with a perfect blood glucose level, or have other diabetes related questions for that matter, schedule a complimentary phone consult with me here: www.consultwithdrjody.com/type1
You CAN be healthy and happy while living with diabetes. To your health!
One Drop Guide: Why Is My Blood Sugar High In The Morning?
What’s one of the most frustrating things to deal with when you have diabetes? Waking up to a high morning blood sugar! You wake up, roll over, check your blood sugar on your One Drop meter, and see: 247 mg/dL. What!
You’re doing everything you’re supposed to be doing to manage your diabetes like a pro: eating low-carb, going on walks, checking blood sugar regularly; you haven’t eaten, taken insulin, or moved for hours, so what’s the deal?
First Thing’s First: You’re Doing Awesome
Many people experience high blood glucose in the morning, just like you! So know, you are not alone. This is normal! And there are ways to fix it. You just need to figure out the root cause of the issue, which is exactly why we’ve come up with this guide. There are different reasons you can wake up with a high blood sugar, and this guide breaks it down for you.
Why Does Blood Sugar Rise Over Night?
Well, there are actually some good explanations for those mysterious morning highs (anything from dawn phenomenon to not enough medication), and some steps you can take to prevent them. Check out the this mobile-friendly One Drop Guide — Why is my blood sugar high in the morning? — to figure out what the cause might be and what to do about it.
Why Is My Morning Blood Sugar so High?
Q: I have prediabetes and now eat minimal carbs and sugar. My doctor told me to monitor my sugar levels, morning (fasting) and night. At night, two hours after eating, my sugar levels are between 112 and 130 mg/dL (6.2 to 7.2 mmol/L). But in the morning, my fasting sugar level is always higher than the night number. Why is that? What am I doing wrong?
There are a few reasons why your blood sugar may be elevated in the morning. First, it’s important to understand that certain hormonal changes that occur overnight may lead to high blood sugar levels (hyperglycemia) in the morning.
The Dawn Phenomenon
The dawn phenomenon refers to hormonal changes that cause your blood sugar to increase in the early morning hours before you consume breakfast. Your body makes extra blood sugar (glucose) overnight in order to avoid periods of low blood sugar (hypoglycemia) while you’re sleeping and to give you the energy you need to get out of bed.
In people without diabetes, insulin — the hormone that regulates blood sugar — also rises to keep blood sugar stable. However, in people with diabetes who are resistant to the effects of insulin or who don’t produce enough insulin, blood sugar may rise dramatically in the morning (1).
Although the dawn phenomenon is more common in people with diabetes, it can occur in those who have prediabetes as well.
Aside from the dawn phenomenon, there are a few other reasons why your blood sugar may be high in the morning.
It’s important to be aware that your nighttime meal choices can affect your morning blood sugar levels. For example, eating high-carb meals or snacking on sweets before bed can lead to elevated morning blood sugar levels.
To keep your blood sugar stable throughout the night, eat a dinner high in protein, healthy fats, and fiber, and moderate in complex carbs. Avoid carbs that tend to spike blood sugar, such as white bread and white pasta.
If you choose to eat a snack at night, opt for a high-fiber option balanced with protein or a healthy fat, such as a small apple with a tablespoon of natural peanut butter. This can keep your blood sugar more stable while you sleep.
If your doctor has prescribed you blood sugar medication, ensure that you’re following dosage and timing recommendations.
Taking the wrong dose or taking medications at the wrong time can cause blood sugar fluctuations and can lead to elevated morning blood sugar levels.
Exercise and weight loss — if needed — are some of the best ways to increase blood sugar control in people with prediabetes.
Going for a walk after meals can significantly reduce blood sugar levels, which can improve overall blood sugar control. For example, research shows that walking for 15 to 20 minutes after meals can significantly reduce blood sugar levels over a 24-hour period in people with prediabetes and diabetes (2, 3).
Choosing the right foods, taking medications as directed, losing weight if necessary, and exercising — especially after meals — are all ways to increase overall blood sugar control and decrease your chances of experiencing high blood sugar levels in the morning.
If you’re still experiencing high morning blood sugar levels after making these changes, consult your doctor for advice.
Jillian Kubala is a Registered Dietitian based in Westhampton, NY. Jillian holds a master’s degree in nutrition from Stony Brook University School of Medicine as well as an undergraduate degree in nutrition science. Aside from writing for Healthline Nutrition, she runs a private practice based on the east end of Long Island, NY, where she helps her clients achieve optimal wellness through nutritional and lifestyle changes. Jillian practices what she preaches, spending her free time tending to her small farm that includes vegetable and flower gardens and a flock of chickens. Reach out to her through her website or on Instagram.
Do you wake up with a blood glucose level that’s higher than when you went to bed? You might wonder how this could be. Is this “dawn phenomenon” serious, and what can you do about it?
Our reader Mishelle commented here, “I don’t eat during the day. My blood sugar is still too high in the morning…sometimes 125–140ish.”
How can Mishelle’s glucose levels go up if she didn’t eat anything? She probably has a mild case of dawn phenomenon. Her glucose is going up from sources other than digested food. Some of it is produced by the liver from stored starch and fatty acids. Livers that produce too much glucose are one of the main ways diabetes causes high blood glucose levels. Other organs also produce small amounts of glucose. This is called “gluconeogenesis” for you science freaks out there.
Organs do this to keep blood glucose from going too low at night or other times of not eating. From about 2 AM to 8 AM, most people’s bodies produce hormones, including cortisol, glucagon, and epinephrine. All these hormones increase insulin resistance and tell the liver to make more glucose. The idea is to get you enough glucose to get out of bed and start the day. The whole process is apparently started by growth hormones.
Everyone has a dawn phenomenon. Otherwise they’d be too weak to get breakfast. But in people without diabetes, insulin levels also increase to handle the extra glucose. People with diabetes can’t increase insulin levels that much, so their early morning blood glucose levels can rise dramatically.
Experts disagree on how many people have a dawn phenomenon. Estimates range from 3% to 50% of Type 2s and from 25% to 50% of Type 1s.
Is dawn phenomenon a serious problem?
It can be serious. According to the American Diabetes Association, “Some people with dawn phenomenon find that their glucose continues to rise until they eat in the morning. For others, levels will settle down a few hours after waking, regardless of whether or not they eat.”
Either way, that can be a long time to spend with elevated blood glucose levels. For some people, like Mishelle, the highs aren’t that dangerous. Others go much higher.
According to columnist Wil Dubois, the higher your A1C, the more likely you are to have a significant dawn phenomenon. It could be that spending a number of hours each morning out of control is having a significant effect on your overall control.
So it’s worth trying to get dawn phenomenon under control. How can you do that? You have to figure out what is triggering it and then try some possible solutions.
Some people have high glucose levels in the morning because their medicines wear off overnight. This could be true of medicines such as insulin, sulfonylureas, and metformin. If you are taking any long-acting medicine, consider asking your doctor about changing meds, doses, or times. Our reader Mishelle might benefit from taking her metformin later in the evening, for example. Metformin is good at keeping a lid on the liver.
In some cases, medicine can be too strong. If your glucose goes too low in the night, you could have a rebound high in the morning. This is called the Somogyi effect. Wil Dubois says, “If you are waking up high and are suffering pounding headaches, or find your sheets sweat-soaked, the odds are you are having lows in your sleep…You need to visit with your doctor about taking less meds.
According to Dubois, the new insulins are much less likely to cause a Somogyi reaction. But because of cost, people are going back to NPH insulin. NPH is cheaper, shorter-acting, and more likely to cause a low, leading to a rebound high in the morning.
What can you do to reduce or eliminate dawn phenomenon? Diabetes blogger David Mendosa says many things work for some people and not for others. People report blocking the dawn phenomenon with a green apple or a resistant cornstarch product at bedtime. These might keep a low, steady level of glucose coming and might prevent nighttime lows and highs.
Not eating at all after 7 PM probably won’t help. It will set you up for a Somogyi rebound. A protein snack like nuts or cheese at bedtime might help. But you will have to experiment and keep records for yourself. Everybody is different.
Mayo Clinic doctor Maria Collazo-Clavell, MD, says avoid carbs at bedtime. She also says an insulin pump can help a lot. You can program it in advance to increase your insulin when the dawn phenomenon starts to kick in. You might have to check a few middle-of-the-night levels to find out when the phenomenon starts for you, or if you are going too low.
Vinegar might be another option. You can take tablets or a liquid. Most people I’ve read commenting on various sites needed 4–6 vinegar tablets at bedtime to avoid a morning spike. There’s not much research, though vinegar has been shown to reduce insulin resistance.
Hope this helps, Mishelle. Readers, do you have other ideas? What have been your experiences with dawn phenomenon?
Want to learn more about the Somogyi effect? Read “Somogyi Effect,” by contributing editor Robert S. Dinsmoor.
Christy Parkin, MSN, RN, CDE, responds:
In the early morning hours, hormonal changes in your body will naturally cause blood glucose to rise. For people who don’t have diabetes, the increase in blood glucose is offset by increased insulin production. For people with diabetes, this can be a problem.
There are a couple of things going on that make your glucose rise in the morning. One of these is insulin resistance—a condition that means your body’s muscle and fat cells are unable to use insulin effectively to lower blood glucose. However, insulin resistance also affects how your liver processes, stores, and releases sugar, particularly at night. The liver is supposed to release small amounts of glucose when you’re not eating. But in type 2 diabetes, the liver dumps more glucose than is needed into the bloodstream, especially at night. So, while your hormones are causing a natural rise in blood glucose, your liver is releasing even more sugar into your system. And because your insulin resistance prevents your muscle and fat cells from using the sugar, your blood glucose level rises.
Unlike mealtime blood glucose, which can be somewhat controlled by diet and exercise, high fasting blood glucose usually needs to be treated with medication. You should talk to your doctor about medications that can help you obtain good control. You may also want to read our September 2008 story “Rocky Morning Highs.”
Interested in more information about healthy living with diabetes? Diabetes Forecast magazine.
Q: I have had Type 2 diabetes since 2005. My doctor has me taking a combination of metformin and glibenclamide (a sulfonylurea). Until a few weeks ago, my fasting blood sugar was always around 100 mg/dl. Now it rises overnight, and I wake up as high as 200 mg/dl even with nothing to eat after dinner. Why is this happening? What can I do about it?
A: With Type 2 diabetes, the pancreas gradually loses the ability to produce insulin over the course of time. Insulin may also start to work less effectively, particularly in people who gain weight, exercise less, experience more stress or develop other health problems.
In your case, since you are not eating at night, your blood sugar is likely rising overnight because your liver is producing more glucose than your pancreas can handle. You’re just not making enough insulin on your own, at least during the night. There are many options for fixing this, ranging from lifestyle changes (dietary modifications, increasing physical activity) to adding new medical treatments (oral or injectable medications) to simple dosage adjustments.
Your health-care team can make adjustments to your diabetes treatment plan based on specific/individual needs. See your physician regularly and communicate between appointments if you suspect that adjustments may be in order. Of course, it helps to have plenty of blood sugar values to share. Without data, it will be difficult for your health-care team to diagnose the problem and figure out the best possible solutions.
Want to learn more about blood sugar levels that rise overnight? Read “The Dawn Phenomenon and Somogyi Effect: What You Can Do” and “Controlling the Dawn Phenomenon.”
How It Works
Generally, the normal hormonal changes your body makes in the morning will boost your blood sugar, whether you have diabetes or not. If you don’t, your body just makes more insulin to balance everything out. You don’t even notice that it’s happening.
But if you have diabetes, it’s different. Since your body doesn’t respond to insulin the same as most, your fasting blood sugar reading can go up, even if you follow a strict diet.
The boost in sugar is your body’s way of making sure you have enough energy to get up and start the day. If you have diabetes, your body may not have enough insulin to counteract these hormones. That disrupts the delicate balance that you work so hard to keep, and your sugar readings can be too high by morning.
The effects of the dawn phenomenon can vary from person to person, even from day to day.
Some researchers believe the natural overnight release of what are called counter-regulatory hormones — like growth hormones, cortisol, glucagon and epinephrine — makes your insulin resistance stronger. This will make your blood sugar go up.
You may also have high blood sugar in the morning because:
- You didn’t have enough insulin the night before.
- You took too much or too little medicine.
- You ate the wrong snack before bedtime.
The Overnight Blood Sugar Conundrum
By Adam Brown
How do I stay in range while sleeping?
In the past week, I’ve seen these two 24-hour CGM traces:
It’s amazing that the same overnight insulin dose produced those two markedly different midnight-to-9am glucose outcomes (left side of each graph).
The example on the right, I believe, was caused by: (i) a big late-night dinner after barely eating all day, and (ii) changing my pump’s infusion set and reservoir right before bed, without confirming a few hours later that it was working properly.
Whatever the cause, I woke up at 7:50 am on Tuesday at 262 mg/dl – exhausted, frustrated, and late for a team event. I changed my pump site quickly, took a huge six-unit insulin bolus, and decided at the last minute to ride my bike 4.5 miles to the event.
Halfway down the steep hill from my house, I had that sinking feeling: “Gah! I should go back home and get glucose tabs, just in case.” I cycled back, grabbed the tabs, and then my prediction turned out to be correct 15 minutes later – halfway to the event, my glucose was dropping faster than I’d ever seen in my life. I ate three tabs as a buffer and luckily avoided going low.
By 9:05 am, I had arrived for our team photo event covered in embarrassing business-casual sweat, but back in range. And from there, the workday could actually begin.
I tell this story to illustrate a larger point – overnight blood sugar has a major impact on the next day. Unfortunately, keeping glucose in range every single night is very difficult without an automated system. This article shares some of my Bright Spots for beating this nighttime conundrum, gleaned from those nights like the example above on the left. Enjoy, and get all my Bright Spots & Landmines here (free PDF) or at Amazon.
Overnight BGs in a tight, safe range (80-140 mg/dl): early dinner, no snacking, disciplined bedtime corrections
Keeping my blood glucose (BG) in a tight, safe range overnight (80-140 mg/dl) dramatically improves my sleep quality and next-day restfulness. Nighttime highs and lows really disrupt sleep, and the more dramatic or prolonged they are, the worse I end up feeling the following morning: exhausted, grumpy, and likely to either overeat (to correct a low) or remain high for much of the next day.
What makes nighttime BGs profoundly difficult is that they are influenced by a number of factors: food during the day; dinner and nighttime snacking (size, type, timing); daytime exercise; insulin dose and timing; and more. Basal insulin requirements can also change drastically from night to night – in studies of automated insulin delivery, people with diabetes sometimes need half as much basal insulin on some nights and twice as much insulin on other nights. This makes repeatable perfection challenging!
Nighttime is also a scary time to live with diabetes – given the potential for severe hypoglycemia – so my instinct is to be ultra conservative before bed with food (eating too much) and insulin dosing (taking too little). Upcoming automated insulin delivery systems will be a major overnight Bright Spot, but not everyone may want to or be able to use them.
When I have a Bright Spot night of BGs (80-140 mg/dl), there are usually some key enablers:
I have a filling early dinner with lots of veggies, a modest portion of protein, and plenty of fluids at least three hours before bed.
I stick to a black-and-white rule to prevent snacking – I do NOT eat after dinner unless I’m low.
I correct lows before bed with a quantity-limited food (a small apple, glucose tabs, Smarties), eating just enough to get back to my target range.
Just as with food, glucose monitoring (ideally with CGM) is the key feedback mechanism for this Bright Spot – am I consistently going high or low during sleep? How does my BG usually change from pre-bed to waking up? What might be driving the pattern, particularly my food habits?
I’m careful about changing my overnight basal insulin dose from night to night, since my routine tends to vary minimally. I get into trouble when I use one isolated night of BGs (e.g., two hours spent low on Monday) and impulsively change my entire weekly basal insulin plan. This is never a good idea. My personal nighttime patterns are often inconsistent (high on Monday, low on Tuesday), and I find my eating habits are typically the biggest driver. (The obvious exception is if I have a consistently high or low pattern on most nights in a period of two weeks – then I do change my basal insulin dose.)
Look for overnight BG patterns: does my BG stay relatively level throughout an average night (within about 30 mg/dl from before bed to waking up), or does it consistently rise or fall from bedtime to wakeup? If BG is consistently changing on most nights, talk to your healthcare provider about your medication dose. (Insulin users can read more on this topic from Gary Scheiner at diatribe.org/basaltesting)
On Bright Spot nights, what combination of factors may have contributed to in-range BGs? When my BG goes far out of range from pre-bed to waking up, was there an obvious driver? If this happens consistently, how might I change my eating routine or medication dose?
Focus on food – it’s the biggest driver of my high and low BG patterns overnight. What foods and timing help keep me in range overnight, including dinner and nighttime snacks? Can I be more consistent with my evening eating? What bedtime low correction brings me back in range and keeps my BG stable overnight?
Remember that overnight perfection is difficult when manually dosing insulin. Strive for improvement, use data to make decisions, and experiment conservatively. I’m always in learning mode and still constantly making mistakes.
Use automated insulin delivery overnight, if it’s accessible to you (also known as a “hybrid closed loop” or “artificial pancreas”). These systems are outstanding overnight – almost every morning while wearing one, most people wake up around 90-120 mg/dl.
If using a pump in open loop (no automation), remember basal insulin changes should be made at least one hour before the actual low or high occurs (i.e., a change in basal dose takes time to actually affect my BG).
Want more tips like this? Get Bright Spots & Landmines: The Diabetes Guide I Wish Someone Had Handed Me here for free/name your own price. You can also purchase it at Amazon in paperback ($6.29) and Kindle ($1.99). The print book is priced at cost to ensure widespread access, and 100% of proceeds from digital downloads benefit The diaTribe Foundation, a 501(c)(3) non-profit.
Have you benefitted from Bright Spots & Landmines? Could you take a few minutes to write a one-sentence Amazon review sharing your experience? It would help us so much!
Reasons for a high fasting blood glucose value in the morning for Type 1 Diabetes
First of all, it can be totally normal that the amount of insulin during the night is simply not enough to prevent the blood sugar from rising which means that something is wrong with the basal rate.
What do we need basal insulin for anyway? Here is just a quick recap of the basics: the liver continuously releases some sugar into the blood between meals and at night in order to keep the blood sugar at a healthy level. Of course, insulin is needed for this sugar to be transported to the cells. The basal insulin that should normally make up 40-50% of our total insulin requirement is needed for this continuous flow of sugar. And of course the demand can also change over time. For example, if you catch a cold or get a fever – which probably everyone could notice already at some point by looking at their values.
Changes in the demand for insulin can also occur gradually, for example, when gaining or losing weight, aging or hormones are changing as it happens during the menopause for women.
Normally, the basal insulin demand of almost every person rises in the early morning hours (mostly between 3 a.m. and 6 a.m.). This is normal. However, the rise can vary in intensity. This is called the dawn phenomenon. The reason for this is a more intense release of growth hormones, adrenalin, cortisol and glucagon, which are also known as the antagonists of insulin. With basal insulin injections that cannot be adjusted on an hourly basis, this problem is often not as easy to solve, but an insulin pump can deliver more insulin in the hour depending on the higher demand of insulin.
Now, coming to the topic of sleep: those who are stressed, those who sleep badly – and oftentimes too little (under 6 hours) – tend to have higher cortisol levels. It is important to remember that cortisol and insulin aren’t best friends, because cortisol counteracts the insulin which results in increased blood sugar values. Approximately 1.5 hours after going to sleep, our insulin demand reduces. At night time, between 2 a.m. and 3 a.m., we have the lowest insulin requirement. When we get up, the demand rises sharply, which is again due to hormones that regulate our blood pressure. Those that wear a continuous glucose meter (CGM) can analyze those processes very well.
Dinner, protein and fat
Who doesn’t know that feeling of coming home late after work with a monstrous hunger and right before going to sleep having a big meal? At night time, when lying in bed, we are digesting very slowly and now the late meal can take revenge with a high fasting blood glucose value. Especially, if the meal contained a great amount of protein and fat, for example like eating a steak with a salad. After a meal like this, a delayed rise in blood sugar values can be expected. The amount of protein in our food influences the blood sugar values but slowing down blood sugar absorption. with a time difference. Depending on the amount, the sugar rises about 3-8 hours later. On the one hand, protein building blocks (amino acids), which have an effect on the blood sugar, are converted into sugar, but there are also amino acids that lead to an increased release of glucagon which causes the liver to release more sugar. So, for your next dinner keep an eye on your protein-fat-calculations.
Watching a funny video on YouTube or binge-watching our favorite series on Netflix? Most of the time, we combine the time in front of the screen with yummy snacks that make the TV evening really relaxing. And relaxation is good for you. This can, however, also be tricky at times because snacking in the late evening or night can be the reason for high blood glucose values, as well. Especially if you forget the insulin.
Tip: If possible don’t snack at all (ok, ok, this is not a good one ;)). But, if you have to, then do remember to inject your insulin. Each carbohydrate exchange, which is equal to 15 grams of carb makes the blood sugar rise between 30-50 mg/dl (1.7-2.8 mmol/l) and this can easily be reached with a few chips.
Too high blood sugar in the evening
Some people start into the night with a high blood glucose value for various reasons. In this case, work towards getting your blood sugar close to your target range in the evening. Your basal insulin dose is appropriate when your blood sugar stays steady or varies no more than 30 mg/dl. However, those who start into the night with a high blood glucose value often wake up with a high blood glucose value, as well.
Last but not least, a high fasting blood sugar can also be caused by a hypo over night. During a hypo, adrenaline is released which leads to a release of sugar from the liver and makes the blood sugar rise with a time delay. To check this, a nightly check of your blood glucose values between 2 a.m. and 3 a.m. can help.