Glycogen storage diseases are inherited disorders of carbohydrate metabolism.
In liver Glycogen Storage diseases (GSDs), an individual is prone to hypoglycaemia, or low levels of glucose in the blood.
These are disorders that you get because of your genes or genetic make-up. You get your genes from your parents.
A term used to describe the huge number of chemical reactions that take place in your body every day. Most of these reactions are linked in some way to using food to provide energy for the body or to help the body grow and repair itself. If you have a disorder of metabolism (also called a metabolic disorder), there is a problem with one or more of those reactions.
Carbohydrate is one of the main nutrients that you get from food. Most of the carbohydrate in your diet comes from starchy foods such as bread, rice, pasta, noodles and potatoes. You can also get carbohydrates from sugary foods such as sweets, cakes, biscuits, jam, honey and syrup.
In other words, if you have a liver GSD, you have a problem with glycogen metabolism that needs careful management to avoid your blood glucose levels going too low and causing problems. Beyond that, the management of GSD aims to support you live a full and healthy life.
Carbohydrate in one of its simplest form. Blood glucose (sometimes called ‘blood sugar’) is one of the main energy sources for your body.
This is a term you may not be familiar with. As such, we have provided a separate Frequently Asked Questions on glycogen. Click here to read more. In simple terms, the body uses glycogen to store glucose that isn’t needed for immediate use. When blood glucose levels start to go low, glycogen can release glucose back into the blood. If you have a liver GSD, there is a problem in getting glucose from the glycogen stores.
This means ‘low levels of glucose in the blood.’ (Do not confuse this term with ‘Hyperglycaemia’ which means ‘too much glucose in the blood’.)
Hypo = Low
Hyper = High
Hypoglycaemia requires urgent attention.
Individuals with liver GSDs require careful lifelong management from a specialised Metabolic Centre.
If you have a liver GSD, your medical and dietetic management will aim to minimise symptoms and promote growth, development and good health. Symptoms can vary depending on which type of GSD you have (See below for more details.) but, if you have a liver GSD, avoiding episodes of hypoglycaemia (sometimes referred to as a ‘hypo’) is a key priority for you. A ‘hypo’ occurs when blood glucose levels go too low.
YOUR LIVER MAY BE ENLARGED
The medical term for this is hepatomegaly. This is due to glycogen stores building up in your liver because your body cannot break glycogen down into glucose. From the outside, this can look like a large stomach which seems out of proportion with the rest of your body. With good management, the liver reduces in size over time.
As your body cannot use its glycogen stores to keep blood glucose levels ‘topped up’, you cannot go for too long between meals. This is particularly true of young children, who have high energy demands for their size. For example, in babies who have not yet been diagnosed, parents may comment on how regularly they cry out for feeding.
To grow properly, children need energy. In untreated liver GSDs, there are problems with the body maintaining a steady energy supply. Not surprisingly, this can interfere with growth and children with GSD may appear short for their age. However, with good management, growth will improve.