Type 1 Diabetes: Symptoms, Treatments, & Breakthroughs
Medically reviewed by C. Fookes, BPharm Last updated on Jul 4, 2019.
What Is Type 1 Diabetes?
Type 1 diabetes is a lifelong disorder in which the pancreas produces little or no insulin. Insulin is a hormone that allows glucose (sugar) to be taken up into cells to produce energy. It is vital for our survival. People with type 1 diabetes require regular daily injections or infusions of insulin to keep them alive.
Although it can be diagnosed at any age, children are more likely than adults to develop type 1 diabetes with peaks in presentation occurring between the ages of five to seven and around the time of puberty. Males are more likely to be affected.
Worldwide, there is a wide geographical variation in presentation. In the U.S., approximately 20 to 30 people are diagnosed for every 100,000 person-years, whereas in China the rate is only 0.1 person per 100,000 person-years. Finland has the highest rate of type 1 diabetes in the world, with 60 people per 100,000 person-years developing the disease.
What Causes Type 1 Diabetes?
Experts haven't worked out the exact cause of type 1 diabetes, but they do know it requires both a genetic disposition to the disorder as well as an environmental insult to trigger the condition.
For nearly four decades, scientists have been trying to work out which genetic loci contribute to type 1 diabetes risk. A lot of information came from one massive project, called the Type 1 Diabetes Genetics Consortium (T1DGC), which collected and genotyped over 14,000 samples. By far the strongest association has been attributed to the human leukocyte antigen (HLA) region, which maps to chromosome 6p21.31.
This region contains over 200 genes, and both susceptible and protective DR-DQ haplotypes (groups of genes) have been identified. Reported odds ratios for developing type 1 diabetes range from 0.02 to >11 for specific DR-DQ haplotypes. More than 40 non-HLA susceptibility gene markers have also been confirmed.
In addition to being genetically susceptible, the emergence of type 1 diabetes also requires an environmental "trigger". Viral exposure, conditions inside the uterus during fetal development, the host's microbiome, or diet have all been suggested as possible triggers; however, there has not been one trigger that has been implicated in all cases of diabetes. In addition, there also appears to be several preclinical stages of type 1 diabetes, and the progression through these stages may take years. This makes identifying a trigger even harder.
What Is Insulin And Why Do We Need It?
Insulin is a hormone that is produced naturally in our bodies. Its main role is to allow cells throughout the body to uptake glucose and convert it into a form that can be used by these cells for energy. Without insulin, we cannot survive, and death from diabetes was a common occurrence until insulin was discovered in the early 1900s by Frederick Banting and Charles Best.
Insulin is made by beta cells, which are only found in the Islets of Langerhans (distinct clusters of 3000 to 4000 cells) within the pancreas. When people without diabetes eat food, these beta cells sense the sugar in the blood and release just the right amount of insulin necessary to maintain normal blood sugar levels.
The immune system of people with type 1 diabetes destroys these beta cells, which means they produce little or no insulin. Glucose and carbohydrates from food end up "trapped" in the blood - causing hyperglycemia (high glucose levels in the blood). Meanwhile, even though glucose levels in the blood are high, glucose levels inside the cells are extremely low, and so the liver starts secreting glucagon (glucagon is a hormone that converts stored glycogen in the liver to glucose). In an effort to remove some of the glucose from the blood, the kidneys start excreting glucose in the urine. All of these physiological processes contribute to the symptoms of type 1 diabetes.
What Are The Symptoms Of Type 1 Diabetes?
The two most common symptoms of diabetes are excessive thirst (called polydipsia) and excessive urination (called polyuria), both directly attributable to high levels of glucose in the blood.
So why do high levels of glucose in the blood make your thirsty and urinate more?
It's all to do with osmosis and the movement of solvents from a less concentrated solution to a more concentrated one. In people with diabetes, the urine becomes concentrated with glucose. The body tries to balance out this high concentration of glucose by diffusing water from the blood stream into the urine, which leads to more frequent urination. Unfortunately, now the blood lacks water and is more concentrated with solutes which causes thirst.
Other Symptoms Of Type 1 Diabetes
Other common symptoms of type 1 diabetes include increased appetite and weight loss, tiredness, and general fatigue.
All of these reflect the fact that the cells are unable to uptake glucose from the blood stream which is necessary for making energy. This lack of energy is responsible for the symptoms of hunger, tiredness, and general fatigue. The body tries to compensate by burning fat and muscle instead, which leads to weight loss.
High levels of sugar in the urine can trigger yeast infections with symptoms such as itching or redness in the genital region or an unusual discharge. Small cuts or grazes are more likely to become infected and some people may report muscle cramping or blurred vision from dry eyes.
Serious symptoms of type 1 diabetes requiring urgent medical attention include a fruity, chemical smell on the breath (smells like nail varnish); nausea or vomiting; a fever; stomach pains; or a serious loss of appetite.
Treatment For Type 1 Diabetes
Type 1 diabetes is treated with insulin, which is given either by injection several times a day or as a continuous infusion via an insulin pump. At the moment, insulin isn't available as a tablet form, because it has proven to be hard to develop a formulation that is resistant to being broken down by stomach acids.
The aim of insulin therapy is to keep blood glucose levels within a normal range throughout the day, minimizing the time spent with high blood glucose levels, but at the same time, avoiding blood glucose levels becoming too low. Check with your doctor about what target blood sugar level is recommended for you, based on your age or other pre-existing medical conditions. The Mayo clinic recommend the following blood sugar levels prior to eating:
- Between 80 and 120 mg/dL (4.44 to 6.7 mmol/L) for people aged 59 or younger without other underlying medical conditions
- Between 100 and 140 mg/dL (5.5 to 7.8 mmol/L) for people aged 60 or older, or for those with other medical conditions or with low hypoglycemic awareness (a reduced ability to sense low blood sugar levels).
Levels two hours after eating should not exceed 180 mg/dL (10 mmol/L).
Even though this goal sounds simple, it often isn't easy to achieve. How much insulin is needed changes depending on the type and quantity of food eaten, body stresses and illness, and how much you exercise. In addition, skin temperature and your degree of hydration can affect how well insulin is absorbed.
Types Of Insulin
Insulins are usually grouped into different types based on how quickly they work in the body and how long they last for.
Rapid- and short-acting insulins are usually taken immediately prior to a meal to cover the increase in blood glucose from food. They can take from 15 to 30 minutes to start working and are usually administered together with a longer-acting insulin.
- Rapid-acting insulins: insulin lispro (Humalog, Admelog), insulin aspart (Fiasp, Novolog), insulin glulisine (Apidra)
- Short-acting insulins: insulin regular (Humulin R, Novolin R).
Intermediate-acting insulins cover blood glucose elevations that occur when rapid- or short-acting insulins stop working. They are usually administered twice a day in combination with a shorter-acting insulin.
- Intermediate-acting insulins: insulin isophane (neutral protamine hagedorn [NPH] insulin) (Humulin N, Novolin N)
Long-acting insulins attempt to mimic the way the body naturally releases a low level of insulin continuously throughout the day. They are usually taken once or twice a day in combination with shorter-acting insulins.
Insulin And The Importance Of Monitoring
One of the most important things to remember about insulin is that once you have had your insulin injection, you can't stop the medicine from working, so following insulin up with the food you intended to eat is a must.
You will also need to regularly monitor and record your blood glucose levels several times a day. Although continuous insulin pumps with inbuilt blood glucose monitors are now available, these are quite costly and unfortunately, most insurance companies will not pay for them.
If you catch a cold or the flu; develop nausea, vomiting, or abdominal pain; start to urinate more frequently; or develop unusually high blood glucose levels, then you may need to test your urine for ketones, and your doctor should ensure you have the right testing strips to use for this.
Always Keep In Mind The Benefits Of Insulin
It can be difficult for children and teenagers to really comprehend the importance of having to be strict with their diet, insulin dosage, and blood glucose monitoring. Although most are told that good insulin control throughout their lives will reduce their risk of developing eye, kidney or nerve damage, these complications may seem too far down the track to give them the motivation needed to deal with their diabetes right now.
But there are very important short-term benefits that arise from good blood sugar management. More energy for sport, a better concentration span, and a more even-tempered mood can be directly attributable to good diabetes control.
Food And Exercise Do Matter
Working out which foods are good or bad for your blood sugar levels can also help make managing your diabetes easier. It is not a good idea just to eat whatever you want and then just take insulin to cover it. If you eat more healthy types of food it is easier to estimate carbohydrates and calories and you are less likely to develop high blood sugar levels after a meal.
Exercise is the ultimate way of keeping yourself healthy when you have diabetes, but managing blood sugar levels during exercise may be initially challenging, especially because everybody's makeup is different and there is no one size fits all approach.
To keep your blood sugar levels from going too low during exercise, you will need to check them before you start, during the activity, and after you have finished exercising. Exercise is best started at a blood glucose level above 140 mg/dL. Anything less than that and you should have a snack 30 to 60 minutes before you start. Activity can also add to the effects of insulin, for example, a 1 unit bolus may act more like a 2 or 3 unit bolus. It may take some trial and error, but if you aim to improve on any mishaps from the last time you will eventually be rewarded with the freedom to do whatever activity you want.
Exciting Advances In The Management And Treatment of Type 1 Diabetes
The first automated insulin delivery device (often called an "artificial pancreas") was FDA approved in September 2016 for adults and children aged 14 and older. This device consists of an insulin infusion pump connected to an implantable blood glucose monitor which monitors blood glucose levels every five minutes and delivers insulin when needed. More than 18 different types of these systems are currently in use or still in development.
Islet replacement is being investigated as a way to cure type 1 diabetes. The first human clinical trials have been done using encapsulation techniques to regrow the islets cells, with very promising results.
Glucose-responsive insulin - a type of insulin that only kicks in when your blood sugar levels are high - is also an area of exciting research.
Scientists are still investigating triggers of type 1 diabetes, and ways to reduce or eliminate them. A 2019 study concluded that rotavirus vaccination is associated with a reduced incidence of type 1 diabetes in children.
There are many companies and professional organizations aiming for a cure for type 1 diabetes. Let's hope they soon reach their goal.
Finished: Type 1 Diabetes: Symptoms, Treatments, and Breakthroughs
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