Diabetes is a chronic disease that affects how the body processes glucose (sugar). People with diabetes need to carefully manage their blood sugar levels to stay healthy. Blood sugar control can be extra challenging while sleeping, because the body undergoes several changes throughout the night.
Blood sugar regulation during sleep
During the day, the body aims to keep blood sugar levels in a healthy range between 70-130 mg/dL before meals and under 180 mg/dL after meals. To achieve this, the body relies on two key hormones:
- Insulin lowers high blood sugar
- Glucagon raises low blood sugar
When a person with diabetes sleeps, the body’s regulation of these two hormones changes:
- Growth hormone levels increase, which can raise blood sugar.
- Cortisol levels drop, which can also raise blood sugar since cortisol helps regulate glucose.
- Insulin sensitivity decreases, making it harder for insulin to lower blood sugars.
- Insulin secretion may decrease, especially during the deeper stages of non-REM sleep.
These shifts make it more likely for blood sugar levels to drift out of range during sleep. High blood sugar levels overnight can lead to serious short-term and long-term health problems.
Monitoring blood sugar at night
To detect high and low blood sugars while sleeping, people with diabetes may use:
- Continuous glucose monitor (CGM) – Measures glucose levels throughout the night and sounds an alarm for highs and lows.
- Blood glucose meter – Requires periodically waking up to prick finger and check blood sugar.
Without proper monitoring, dangerously low blood sugar (hypoglycemia) can occur at night and go undetected. Very low blood sugar during sleep can potentially lead to seizures or even death in severe cases.
How mealtimes and activities impact nighttime blood sugar
Blood sugar levels during sleep are heavily influenced by the timing of meals and activity earlier in the day. Some key factors that affect overnight blood sugar levels include:
- Carb intake at dinner – More carbs result in higher overnight blood sugars.
- Bedtime blood sugar level – Ideal bedtime glucose is between 100-140 mg/dL.
- Exercise in evening – Can lower blood sugar and risk of highs overnight.
- Alcohol in evening – Can cause blood sugar to drop during sleep.
- Stress hormones in evening – Can raise blood sugar levels at night.
Working with a healthcare provider, people with diabetes can optimize their meal timing and pre-bedtime routine to help achieve better blood sugar control overnight.
Treating low blood sugar at night
People with diabetes may experience low blood sugar (hypoglycemia) during sleep, especially if they take insulin or certain oral diabetes medications. Symptoms of low blood sugar at night can include:
- Sweating
- Fast heartbeat
- Anxiety
- Nightmares
- Restlessness
Low blood sugar is treated by consuming fast-acting carbohydrates such as:
- 4 glucose tablets
- 1 serving of glucose gel
- 4 ounces of fruit juice
- 8 ounces of milk
It’s important to treat lows during the night to prevent blood sugar from dropping dangerously low. Keeping a fast-acting carb source on the nightstand makes it easier to treat nighttime hypoglycemia.
Impact of diabetes medications on sleep
Certain diabetes medications can also affect blood sugar levels and sleep quality:
| Medication | Effect on Sleep |
|---|---|
| Sulfonylureas (glyburide, glipizide) | May cause hypoglycemia at night |
| Meglitinides (nateglinide, repaglinide) | May cause hypoglycemia at night |
| GLP-1 receptor agonists (liraglutide, semaglutide) | May cause nausea or gastrointestinal issues |
| SGLT2 inhibitors (empagliflozin, canagliflozin) | Increase urination which can disrupt sleep |
People taking medications that increase hypoglycemia risk may need to check their blood sugar levels more frequently at night.
Tips for better sleep with diabetes
Getting adequate, high-quality sleep is essential for managing diabetes. Here are some tips to help improve sleep when living with diabetes:
- Go to bed and wake up at consistent times to regulate circadian rhythm.
- Avoid screen time and caffeine several hours before bed.
- Check blood sugar and take diabetes medicines as prescribed before bed.
- Have a light snack if needed to prevent low blood sugar.
- Use a comfortable mattress and pillow for better sleep quality.
- Reduce fluids before bed to minimize bathroom trips.
- Keep supplies on hand to treat high or low blood sugars.
- Consider melatonin supplements if insomnia is an issue.
- Use a CGM to monitor glucose throughout the night.
Prioritizing healthy sleep hygiene can help people with diabetes wake up with blood sugar levels within the target range.
How diabetes impacts sleep stages and sleep disorders
Diabetes affects how well a person cycles through the stages of sleep at night:
- NREM stage 1 – Transition to sleep. No difference in diabetics.
- NREM stage 2 – Light sleep. Slightly enhanced in diabetics.
- NREM stage 3 – Deep sleep. Often deficient in diabetics resulting in daytime drowsiness.
- REM sleep – Dreaming sleep. Reduced REM in diabetics which impairs memory consolidation.
People with diabetes are also more likely to experience certain sleep disorders including:
- Insomnia – Trouble falling or staying asleep. Caused by hyperglycemia, hypoglycemia, diabetic neuropathy pain, frequent urination.
- Sleep apnea – Interrupted breathing during sleep. Related to risk factors like obesity and high blood pressure.
- Restless legs syndrome – Uncomfortable sensations in legs causing urge to move them.
- Periodic limb movement disorder – Involuntary jerking of legs during sleep.
Treating sleep disorders can help improve overnight blood sugar control in people with diabetes.
Conclusion
Managing diabetes well overnight while sleeping can be challenging, but is extremely important. Fluctuating blood sugar levels, hypoglycemia risk, sleep deficits, and sleep disorders are all concerns. Careful blood sugar monitoring, optimized meal timing, adherence to medication regimens, smart device use, and prioritizing sleep quality help enable smoother blood sugar control and better rest. By being aware of all the factors that influence nighttime glucose regulation and taking appropriate steps to address them, people with diabetes can wake up with blood sugar in the healthy range and feel more rested overall.