When you go to sleep at night the amount of glucose being used is equivalent by the amount of glucose being released by the liver, so the blood sugar levels should theoretically be at the same level. However two processes occur during the night which could alter these levels – and potentially cause problems for those with diabetes. Understanding how the body processes blood sugar is the first step to combating the glucose rise whilst sleeping.
The dawn phenomenon or the dawn effect occurs between 2am and 8am describes the abnormal early-morning increase.
Some researchers believe that insufficient insulin the night before, not high enough anti-diabetic dosage or having a high-carb snack the night before are all factors that cause blood sugar levels to rise.
The somogyi effect or the rebound effect occurs between 2am and 3am and describes a rebound high blood sugar level in response to low blood sugar levels.
It is an instant increase in glucose causing insulin resistance for several hours which in turn leads to the elevated blood sugar levels.
According to Diabetes.co.uk: “The somogyi phenomenon is when prolonged levels of untreated hypolgycemia could lead to stress and high blood sugar levels rebound. This is a defensive response by the body as it released endocrine hormone gulcagon, back up by the stress hormones cortisol and epinephrine.”
However, there are snacks diabetics can eat before bedtime to counter this. These include:
- Celery, tomatoes, carrots
- Peanut butter
- Equally, there are certain foods to avoid late at night. These are:
Equally, there are certain foods to avoid late at night. These are
- Bread and grains
- Starchy vegetables
- Fruit juice
- Beans and legumes
A 2003 study looked at the impact of bedtime snack composition on prevention of nocturnal hypolgycemia in adults with diabetes. The objective was to determine the impact of four bedtime snack compositions on nocturnal glycemic control.
The result was that the need for snacks at night is beneficial in reducing the incidence of nocturnal hypoglycaemia.
It is strongly recommended to avoid carbohydrates in the evening and opt for low-calorie, high protein snacks instead.
You could use an insulin pump to adminster exra insulin during early-morning hours or add some extra fibre to your diet.
Your doctor may recommend a number of options to help you prevent or correct high blood sugar levels in the morning and you should discuss with your GP about possibly adjusting your dose of medication or insulin.