Managing type 1 diabetes

Professional update on type 1 diabetes diagnosis and management with a focus on avoiding DKA

Case report

Lucy is four years old and is a normal, active child but lately she has been going to the toilet frequently and has started wetting the bed again after being dry overnight for months. Lucy complained of a sore tummy and hunger but did not want food, only drinks. Her mother checks her temperature, which is normal, but she feels her skin is very dry. There is a family history of type 2 diabetes,, as Lucy’s father was recently diagnosed. Mum decides a visit to the doctor is needed and suspects a kidney infection, so brings a specimen of urine. The GP agrees that a kidney infection might be the cause and checks the urine using a Clinitest dipstick:

Specific gravity: 1.010, pH: 5.0, ketones: +, glucose: +++.  Negative for leucocytes and protein. The GP suggests that diabetes needs to be considered and advises mum to bring Lucy back fasting for blood tests in the morning.

Overnight, Lucy starts vomiting, her abdominal pain worsens and after a restless night, is groggy and sleepy. Dad is very concerned and decides to check her blood glucose level using his meter and gets a result of 21.2mmol/L, which is high enough to alarm both parents and they head to the emergency department of a Dublin hospital, despite the fact it is a two-hour drive. Lucy’s glucose on arrival is 28mmol/L, with blood ketones of 3.7mmol/L. Lucy is admitted to the paediatric intensive care unit for 36 hours before being transferred to a ward where the family, relieved to have survived the diagnosis, now have to come to terms with Lucy’s need for life-long healthcare and how they will cope with diabetes as she starts school in September.

A combination of genetic and environmental factors is thought to precipitate the autoimmune destruction of the pancreas, which leads to type 1 diabetes. Type 1 diabetes is a life-long condition in which the beta cells of the pancreas produce little or no insulin, a hormone needed to allow glucose to enter cells to produce energy. The more common type 2 diabetes occurs when the body becomes resistant to insulin or doesn’t make enough insulin. While both type 1 and type 2 diabetes result in high blood glucose levels, the pathophysiology and management are distinct and require them to be considered as distinct entities. 

Incidence

Type 1 diabetes is a common chronic disorder with incidence rates for Ireland thought to be 27-to-28 per 100,000 population with little variance annually. In general, the incidence rate in children and young adults peaks between the ages of 10-to-14 years. Incidence rates decline after puberty, although approximately half of people with type 1 diabetes are diagnosed as adults, with many adults initially thought to have and managed as having type 2 diabetes. 

Causes

Various factors may contribute to type 1 diabetes, including genetics and exposure to certain viruses. Some known risk factors for type 1 diabetes include: Family history of autoimmune diabetes; genetic disposition (human leukocyte antigen on chromosome or having another autoimmune condition. Many other possible risk factors for type 1 diabetes have been investigated, though none have been proved.

The Teplizumab Pathway to Prevention study identified relatives of people with type 1 diabetes who had two or more autoantibodies and abnormal blood sugar levels and therefore were thought to have a lifetime risk of developing type 1 diabetes nearing 100 per cent. The study demonstrated that a once-off dose of teplizumab had the ability to delay type 1 diabetes diagnosis by around 24 months. 

Diagnosis

A random blood glucose greater than 11.1mmol/L (normal range 4mmol/L-to-7mmol/L) with the presence of symptoms is diagnostic. Symptoms may include:

Frequent urination.

Excessive thirst.

Fatigue and weakness — need to sleep more than usual.

Increased hunger — possible unplanned weight loss.

Lack of concentration.

Vomiting and abdominal pain.

Bedwetting in children who previously did not wet the bed during the night.

Irritability and other mood changes.

Blurred vision.

In females, a vaginal yeast infection.

Early diagnosis is vital to ensure that diabetic ketoacidosis (DKA) does not develop. DKA is a potentially life-threatening condition that requires urgent medical attention and is the leading cause of death in young people with diabetes. In 2014, one-in-six children diagnosed with type 1 diabetes were admitted to hospital with DKA as a result of late diagnosis. Although the classic symptoms produced by hyperglycaemia are unlikely to be missed in the older individual, there may be a delay in accurately identifying the condition in children who also can deteriorate quickly. It is not uncommon for children to present in severe DKA whilst waiting to have their fasting blood glucose check done. Fasting glucose levels are not necessary in someone who is symptomatic and has an elevated random glucose level.

Diagnosis

Once suspected, type 1 diabetes can be easily outruled/confirmed with a blood glucose meter. If the blood glucose level is elevated (fasting ≥7mmol/L or random ≥11.1mmol/L) and there is the presence of symptoms, the diagnosis is made. Fasting blood glucose, oral glucose tolerance test (OGTT) or a HbA1c are not required to make the diagnosis in the presence of hyperosmotic symptoms. Waiting for the results of these extra tests will only delay the diagnosis and management. Testing blood or urine ketones will help determine if ketoacidosis is likely. Both urine ketones and/or blood ketones can be checked at primary care level and in the presence of hyperglycaemia, is a useful triage tool.

Management

Treatment of type 1 diabetes is life-long injection of exogenous insulin balanced against behaviours, stresses and internal factors. The goal is to keep blood glucose levels as close to normal as possible to delay or prevent complications. Although there are exceptions, generally, the goal is to keep daytime blood sugar levels before meals between 4-to-7mmol/L and 5-9mmol/L after meals, depending on age and control. After the diagnosis, there may be a ‘honeymoon’ period, during which little or no insulin is required as a result of the exogenous insulin injections reducing beta cell glucose toxicity and some cells recovering enough to produce indigenous insulin. However, this phase is temporary and exogenous insulin should be continued during this period.

Insulin management

There are different types of insulin available:

Ultra rapid/rapid-acting insulin for use to drop glucose levels swiftly — Bolus insulin.

Long-acting/longer-acting insulin for maintenance of glucose levels — Basal insulin

Biphasic insulins — either a combination of rapid and long in the same syringe or intermediate-acting insulin, which works over 12-to-24 hours to decrease glucose levels.

See Table 1 overleaf for examples.

There are also different ways of injecting insulin:

Injections — needle and syringe or insulin pen in disposable or refillable varieties. Multiple daily injections that include a combination of daily long-acting insulin combined with mealtime rapid-acting insulin more closely mimic the body’s normal use of insulin.

Insulin pump — a device worn on the outside of the body with a tube connecting a reservoir of insulin to a catheter that is inserted under the skin of the abdomen. The pump is programmed to dispense specific amounts of rapid-acting insulin automatically, known as the basal rate, with additional ‘bolus’ doses of insulin given to cover carbohydrate content of meals or to correct elevated blood glucose levels. Newer pumps include a wireless option with programming done via a wireless device and may include connections to a blood glucose monitoring device with automatic ‘suspend’ when the glucose levels drop. Newer pumps not yet routinely used in Ireland are akin to ‘closed-loop systems’, ie, adjusting dosage for high as well as low blood glucose levels. 

The choice of using a pump or injections is made by the individual in consultation with their diabetes specialist team, as there are advantages and disadvantages to both.

Home blood glucose monitoring

Home blood glucose monitoring is essential to identify hypoglycaemia and hyperglycaemia, adjust insulin dosages based on food intake/activity and to provide feedback on choices already made. Frequency of testing will depend on the individual and stability of diabetes control. Many parents with young children tend to monitor more frequently than requested due to fear of night-time hypos or anxiety over long-term damage from high blood sugar levels. Newer meters may help to address this issue, as over-frequent monitoring may lead to increasing levels of anxiety and rebellion in teenagers.

The traditional finger-prick blood glucose monitoring system measures the level of glucose in the blood on one particular occasion, with most meters having a computer download capacity or a ‘wizard’ to assist calculating insulin dosage.

Continuous glucose monitoring (CGM) systems consist of a small, disposable sensor inserted into the skin, which has a transmitter, connected by a mount to the sensor. The sensor wirelessly transmits results to a receiver and displays those results. This can be in real time, with or without alarms. Various graphs and displays allow for identification of trends and time in range.

Flash glucose monitoring (FGM) consists of a small, disposable, 14-day sensor inserted into the skin and a wireless touchscreen reader device. The reader is used to scan the sensor, resulting in a real-time glucose value, a glucose trend arrow, and a trend graph showing the last eight hours. This graph is known as an ambulatory glucose profile (AGP), which is novel, in that the current data is superimposed on previous days’ graph, allowing interpretation of results based on previous days’ profile and current values.

The finger-prick or laboratory test of glycated haemoglobin (HbA1c) provides an overall picture of what the average blood glucose levels have been over a period of 10-to-12 weeks and is used for discussion about overall diabetes control.

All drivers must retain a record of their blood glucose reading prior to commencing any journey and every two hours of driving. The result must be about 5.0mmol/L to drive.

Dietary management

There is no such thing as a ‘diabetes diet’, rather, a focus on nutritious, low-fat, high-fibre foods, which is healthy eating recommended for everyone. However, there is a focus on carbohydrates, not to limit their intake other than normal considerations, but to match insulin requirements with carbohydrates consumed. Once the individual has a good knowledge of what foods/drinks contain carbohydrate, the next step is to identify how many grams of carbohydrate are in any portion. This involves learning food label-reading, familiarising one’s self with reference books or phone apps, and weighing foods to measure portion size accurately. Carbohydrate counting is an approach that requires commitment of both professional and individual, with courses (CHOICE) or (DAFNE) available, as well as one-to-one education with a dietitian and some online courses. The diabetes team assists the individual in determining their ‘insulin-to-carbohydrate ratio’, which may be different for each meal, but also instructs them on testing it regularly. Carbohydrate counting, once mastered, facilitates better glucose control and gives greater flexibility, choice and freedom to the individual, as the amount of insulin taken correlates to the amount of carbohydrate taken and factors that influence its conversion to glucose.

In older teens and adults, the consumption of recreational substances must be discussed in terms of their interaction with diabetes management and precautions that reduce impact.

Exercise management

Exercise is a vital part of type 1 diabetes management. Staying fit and active throughout life has many benefits, but the biggest one for people with diabetes is it helps control glucose levels and prevents long-term, especially cardiovascular, complications. However, intense physical activity lowers blood glucose levels often for long after the session is completed and increases the short-term diabetes complication of hypoglycaemia. Therefore, people with type 1 diabetes are advised to check their blood glucose levels more often than usual until they are confident they know how each activity affects blood glucose levels, as each type of activity differs. With anaerobic activities such as track events and team sports, weight lifting, body-building gym work, etc, blood glucose levels tend to rise, whereas with aerobic activity such as golf, cycling and jogging, glucose levels tend to drop.

Sick day management

Each person with diabetes is recommended to have an individualised plan for managing their diabetes during an illness, with clear instructions of when professional help is required to manage glycaemia. The plan should detail how much and what extra insulin may be required, based on both glucose levels and ketone levels.

  See example on www.diabetes.ie/living-with-diabetes/managing-diabetes-illness.

Every person with type 1 diabetes will be familiar with their insulin sensitivity factor, more commonly known as the ‘correction factor’, which is the amount of insulin needed to reduce the blood glucose by 2.0mmol/L. Additional insulin is required solely to clear ketones in the presence of hyperglycaemia to prevent DKA. This means the individual is taking a correction dose for hyperglycaemia, plus additional insulin for the ketone level. A sickness plan is only relevant to diabetes management with the underlying cause warranting appropriate attention. 

Psychological effects of type 1 diabetes

Most people think of diabetes as a physical condition and forget the mental aspects of living with the illness. The person with diabetes, or in the case of a child, the parents, are responsible for daily diabetes management, which involves making frequent decisions under sometimes stressful and physically uncomfortable circumstances, what to eat, how much insulin, testing and interpreting results, when and how to treat a low, or exercise. Doing everything necessary can become overwhelming or ignoring management activities causes feelings of anxiety, guilt and even hopelessness. Being diagnosed and living with a chronic condition like diabetes can be really hard, and managing the balancing of everything that is necessary to live well with diabetes can be overwhelming. Being overwhelmed and other negative emotions can affect the ability to sustain relationships, or the ability to have relationships at all. Relationships are essential to share the burden of living with diabetes. The incidence of mental health disorders is doubled for people with type 1 diabetes and all people with type 1 diabetes should be regularly screened. 

Conclusion

For each individual, the targets of optimal glucose control should be the lowest blood glucose profiles and HbA1c levels without severe or frequent hypoglycaemia. This requires continuous support and education and development of self-care skills. Due to the evolving nature of type 1 diabetes management, professional updates are necessary to ensure competence. Diabetes Ireland runs both a type 1-focused and type 2-focused professional study day in March and November annually. To learn more and to register for this year’s type 1 diabetes professional update, see www.diabetes.ie events.

References on request