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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. 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 for blood tests in the morning.
Overnight Lucy starts vomiting and her abdominal pain worsens. After a sleepless night, dad decides to check her blood using his meter and gets a result of 16.2mmol/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 18mmol/L, with blood ketones of 3.7mmol/L. A blood gas reading shows a metabolic acidosis with a pH of 7.15 and bicarbonate of 10mmol/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 lifelong healthcare and how they will cope with diabetes as she starts school this 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 lifelong 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.
Type 1 diabetes is a common chronic disorder with incidence rates for Ireland thought to be 16-17 per 100,000 with slight variance annually – rates for less than 16 years are recorded as much higher in the late 20s. In general, the incidence rate increases from birth and peaks between the ages of 10-14 years but the Eurodiab registries suggest that increasing incidence of type 1 diabetes is especially marked in the under-fives. Incidence rates decline after puberty although approximately one-quarter of people with type 1 diabetes are diagnosed as adults. The UK Prospective Diabetes Study Group 25 suggested that up to 10 per cent of adults initially thought to have type 2 diabetes were found to have antibodies associated with type 1 diabetes.
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 6) or having another autoimmune condition, but these only increase risk and do not predict occurrence. Many other possible risk factors for type 1 diabetes have been investigated, though none have been proven. The current focus of this debate is on gut bacterial composition and its relationship with early development of type 1 diabetes.
A random blood glucose greater than 11.1mmol/L (normal range 4mmol/L–7mmol/L) with the presence of symptoms is diagnostic. Symptoms may include:
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;
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, especially in young people. Children with diabetes can deteriorate quickly and 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. Very early on in the illness post-prandial glucose levels are the first to rise and fasting levels may remain normal.
Once suspected, type 1 diabetes can be easily diagnosed with a blood glucose meter. If the blood glucose level is elevated (fasting ≥7mmol/L or random ≥11.1mmol/L) along with 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. 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 or blood ketones can be checked at primary care level and in the presence of hyperglycaemia is a useful triage tool.
A recent study published by Iyer et al in the PostGrad Medical Journal, examined the timeliness of referral from GPs of patients with suspected new onset type 1 diabetes to specialised diabetes teams. The survey of 300 practices with a 37 per cent response rate showed that only 65 per cent of these GPs that responded referred the individual on the day the suspicion arose as per national guidance, ie, immediate same day referral to confirm diagnosis and provide immediate care. Others would have arranged for a fasting blood test or oral glucose test. Iyer et al further suggest through a case note review that the average delay was almost two days with 55 per cent of delays resulting in presentation with DKA. A limitation of the study was the focus on young children and its small size but nevertheless it highlights an area that could be easily addressed.
Treatment of type 1 diabetes is lifelong injection of exogenous insulin balanced against behaviours, stresses, and internal factors. The goal is to keep blood glucose level 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 4-7mmol/L depending on age and control postprandial rise to below 10mmol/L in children and less than 7.8mmol/L in adults, if feasible. 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.
There are different types of insulin available:
Rapid-acting insulin for use to drop glucose levels swiftly – Bolus insulin;
Long-acting insulin for maintenance of glucose levels – Basal insulin;
Intermediate options – either a combination of rapid and long in the same syringe or intermediate acting insulin, which works over 12-16 hours to decrease glucose levels.
See Table 1 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 may include a wireless option with programming done via a wireless device and/or may include connections to blood glucose monitoring device with automatic ‘suspend’ when the glucose levels drops.
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.
Continuous glucose monitoring (CGM) systems consist of a small three-to-five-day 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 or downloadable later.
New advances coming to market include the flash glucose-monitoring device, consisting 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. Technology already allows upload of results to a phone app but as technology advances it is anticipated that the data will be downloadable direct to a phone for ease of accessing it.
The finger prick or laboratory test of glycated haemoglobin (HbA1c), provides an overall picture of what the average blood sugar levels have been over a period of 10-12 weeks and is used for discussion with a professional on overall diabetes control.
There is no such thing as a diabetes diet, rather 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. Carbohydrate counting is an approach that requires commitment of both professional and individual with courses normally run over a three-day (BERGER) or five-day period (DAFNE) for adults or for children and parents more commonly done as sessions over a few weeks. Once the individual has a good knowledge of what foods/drinks contain carbohydrate, the next step is to identify how many grams of carbohydrate is in any portion. This involves learning food label reading, familiarising oneself with reference books or phone apps and weighting foods to measure portion size accurately. 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, but also gives greater flexibility, choice, and freedom to the individual.
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 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, bodybuilding 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. 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.
For each individual the targets of optimal glucose control should be the lowest blood glucose profiles and HbA1c levels without 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.