Nocturnal hypoglycemia refers to low blood glucose levels while a person is sleeping. Regularly monitoring glucose levels and adjusting insulin dosages can help to prevent nocturnal hypoglycemia.
Hypoglycemia happens when blood sugar levels drop below a threshold that is healthy for a particular person. Typically, this is below 70 milligrams per deciliter (mg/dL). People may also refer to these occurrences as a hypo or a period of low blood sugar. It is more frequent in people who manage their diabetes with insulin.
Sometimes a person may experience nocturnal hypoglycemia, where their blood sugar levels drop while they are sleeping at night. These occurrences can disrupt sleep patterns, cause headaches, and can potentially be dangerous if a person is unable to wake up to treat their nighttime hypo.
This article looks at nocturnal hypoglycemia in more detail, including causes, symptoms, and how to manage and prevent them from occurring.
Nighttime hypos, or nocturnal hypoglycemia refers to periods of low blood sugar levels during the night, typically while a person is sleeping.
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Glucose levels naturally fluctuate during the night as part of the body’s circadian rhythm. However, for people living with diabetes, the complex interplay of insulin, diet, physical activity, and sleep can lead to extreme fluctuations resulting in hypoglycemia.
There are several factors that may cause a person to experience nocturnal hypoglycemia.
- increasing physical activity beyond a person’s usual routine
- alcohol consumption
- overestimating insulin doses
- skipping dinner
- not consuming enough carbohydrates
A 2021 review also notes that the following factors may also increase the risk of nocturnal hypoglycemia:
- older age
- being female
- longer duration of diabetes
Common symptoms a person may experience from nocturnal hypoglycemia include:
- sweating and waking up with damp clothes or sheets
- waking up with a headache
- feeling tired in the morning
- having nightmares
In some cases, a person may experience the Somogyi effect. The Somogyi phenomenon refers to a rebound effect where after experiencing nocturnal hypoglycemia, the body releases a surge of hormones, leading to a person having high blood sugar levels when waking up in the morning.
Read on to learn more about the Somogyi effect.
If a person wakes up as a result of experiencing nocturnal hypoglycemia, they should treat their hypo as they would during the day. This typically involves consuming 15 grams of fast-acting carbohydrates.
To prevent nighttime hypoglycemia a person can adopt to help manage and prevent nocturnal hypoglycemia. This may include:
Regular monitoring of glucose levels
Before going to bed, a person should check their glucose levels. For most people, it is advisable to ensure their blood sugar levels are above 108 mg/dL before going to bed. However, this target may vary slightly between individuals. A person can ask their diabetes healthcare team about suitable blood sugar targets before bed.
A 2021 review advises that a person uses a continuous glucose monitoring (CGM) system to track their glucose levels. Many devices have a function that can release an alarm if glucose levels are dropping below a pre-determined threshold.
Having a bedtime snack
Consuming a small, balanced snack before bed can help prevent overnight drops in blood sugar. For example, a small piece of fruit and some nuts, or a small slice of wholegrain bread and peanut butter. A person can discuss if they should have a snack and suitable snack options with their healthcare team.
If a person engages in physical activity, it may be advisable to try and schedule it earlier in the day to minimize the risk of nocturnal hypoglycemia.
Read on to learn more about how to exercise safely when using insulin.
A person can work closely with a healthcare professional to adjust insulin dosages or other medications as necessary. By ensuring they do not administer too large a dose before bed, a person can help prevent nocturnal hypoglycemia.
Limit alcohol consumption
It is advisable to limit alcohol consumption, especially close to bedtime. If a person living with diabetes chooses to drink, they should consider having some carbohydrates before bed.
In most cases, a person can manage nocturnal hypoglycemia with certain lifestyle and regimen adjustments. A person should contact their diabetes care team if they are experiencing regular episodes of nocturnal hypoglycemia.
If someone is caring for a person living with diabetes and cannot wake them up or they seem unresponsive, they should contact 911 immediately.
Nocturnal hypoglycemia is a potential complication for individuals managing diabetes with glucose-lowering medications. It occurs when blood sugar levels drop below suitable ranges during sleep.
With proper awareness and management strategies, a person can minimize its potential impact. By ensuring glucose levels are above a suitable range before bed, using continuous glucose monitors, and working with healthcare professionals, individuals can significantly reduce the risk of experiencing nocturnal hypoglycemia.