Diabetes is one of the most common chronic illnesses of childhood and is frequently seen in a general paediatric setting. Current estimates for the prevalence of type 1 diabetes in the paediatric age group suggest that there are 3,000 children up to age 16 years, including 270 who are aged less than five years old. 

There is an annual incidence of 50 children aged less than five years with type 1 diabetes.¹ The prevalence of type 1 diabetes in young children is increasing, with worldwide incidence rising by about 3.9% per year and with the fastest increase in incidence occurring in children less than five years of age.²

For improved health outcomes, children with the condition need to be appropriately managed in the context of their family from the onset of the disease, and this requires commitment both from the patient and their family and the medical staff together with lifelong education. 

It also requires diabetes education to be provided to teachers, babysitters, grandparents and other responsible adults who play a key role in the life of the child. Children are not small adults. This is key in understanding the management of childhood diabetes both in hospital and in their homes and communities.

Why is diabetes different in children?

Type 1 accounts for only 5-10% of all cases of diabetes; however, diabetes in childhood is usually type 1. Conversely, a large portion of diabetes in adults is type 2 diabetes.³

Children with diabetes tend to be sicker at presentation than adults. They have a shorter duration of symptoms at presentation and a lower level of C-peptide, demonstrating less functioning beta cells. Indeed, type 1 in adults is characterised by a longer duration of symptoms prior to diagnosis, and with better preservation of residual beta cell function.³

Adults also demonstrated lower frequencies of insulin autoantibodies such as HLA-Dw 3/4. Children with type 1 also have more HLA genes than adults and these are associated not just with an increased diabetes risk, but also with more preceding infections and more metabolic decompensation at the time of presentation.⁴ 

Compared with adults, healthy children are admitted to hospital frequently. During 2010 in Ireland, there were 81,107 children under 14 years admitted to hospital with acute complaints: 33.1% (26,871) of these were aged less than one year old; the remaining 66.1% were in the 1-14 year age group. Of the 72,583 with a listed diagnosis on discharge, 299 of these admissions were diabetes-related.⁵

The management of type 1 in children should be carried out by the diabetes multidisciplinary team, this includes a paediatric diabetes nurse specialist, diabetes dietitian, paediatric endocrinologist, medical social worker and paediatric psychologist. 

During childhood, the multidisciplinary management of type 1 requires continuous attention to glycaemic monitoring, insulin administration, diet and exercise, among other factors. 

Education and advice on diet (comprising carbohydrate and other nutrients consumed, which increase blood sugar levels) and glucose utilisation, including through exercise (which, simply put, requires sugar and therefore decreases blood sugar levels) are the essentials in managing childhood type 1. 

Growth and nutrition requirements change constantly during childhood, requiring diabetes management and education to be responsive to, as well as to pre-empt, these changing physiological needs. Ongoing paediatric diabetes dietetic education is essential. 

Hypoglycaemia and the developing brain

Hypoglycaemia is the most common acute complication of diabetes management in children.⁶ Hypoglycaemia is known to cause neurocognitive impairment in children. Severe hypoglycaemia with unconsciousness or seizures may lead to cognitive decline in children over time.⁷

The developing brain does not store glycogen or perform gluconeogenesis, instead, it relies on a constant supply of glucose from the blood. If hypoglycaemia is severe and prolonged, cerebral glucose utilisation decreases and this leads to neuronal death. 

One group of authors, using electroencephalography (EEG) studies, showed temporary EEG decelerations during periods of severe hypoglycaemia. The same authors then used magnetic resonance imaging (MRI) and showed a reduction in grey matter in cortical areas occurring in children as a result of episodes of severe hypoglycaemia. 

Interestingly, they did not demonstrate these findings in adolescents or adults.⁷ Thus, severe hypoglycaemia may lead to a cognitive decline in children, and this is possibly one of the most concerning features of the management of type 1 in young children. 

Furthermore a randomised controlled clinical trial showed that children with type 1 and episodes of severe hypoglycaemia performed less accurately and more slowly on spatial memory tasks than a control group of healthy, non-type 1 children matched for age and sex.⁸

The authors noted the need for more and larger studies, but nonetheless advised caution when proposing overly strict standards for glycaemic control in young children.

Ages and stages of development

Managing and understanding diabetes in children of all ages and developmental stages is not universal, and instead should be tailored to the age and developmental stage of the child. In this section we will address the problems and possible solutions that may affect children of different age groups.

Infancy (0-18 months)

In this age group, diet and mealtimes can cause problems as young children may only eat when they are hungry, which affects type 1 management. Possible solutions include continuous subcutaneous insulin infusions (so-called ‘pump therapy’) or use of multiple daily injections with both background or basal insulin and boluses of rapid-acting insulin for meals.

Toddlers (1.5 to three years)

During this stage, it can be difficult to distinguish between behaviour and symptoms of hypoglycaemia as causes for bad temper or tantrums. Parents need to be extra vigilant and to familiarise themselves with their child’s individual diabetes.

Pre-school children (three to five years)

The child may fear that he or she did something to deserve diabetes. They may begin to try to control their condition and insulin therapy. Solutions include reassurance and education on the causes of type 1 diabetes and to find something else for them to control.

Less than five years old

Up to five years of age, which is approximately the age of starting school, children’s behaviour, food and activity habits are frequently chaotic. Simply put, the implication for managing type 1 is that parents sometimes have little control over the diet (glucose intake) and activity (glucose utilisation) of their children. 

This can lead to mismatches between glucose and insulin, with consequent periods of hyperglycaemia or hypoglycaemia. This is particularly true when young children are treated with fixed regimes of subcutaneous insulin injection, including intermediate-lasting insulins. 

Due to fear of hypoglycaemia, some parents will choose to tolerate hyperglycaemia, as an attempt to reduce the risk and severity of hypoglycaemia. In recent years, there has been a tendency to treat young children with type 1 with continuous subcutaneous insulin infusions (CSII, or insulin pumps) in preference to multiple daily injections of insulin (MDI). 

As children get closer to the age of five years, they also start recognising that they have diabetes and begin to notice that other children do not. This is a good time to educate the child and to enlist the help of teachers in school. 

Insulin regimes can be tailored and need to be reviewed regularly so that they meet each child’s individual but changing needs.

Five to 12 years old

During these years, children have an increasing amount of freedom over food choices and often eat outside the home. Mealtimes may not be fixed and appetite may vary daily. In general, children have high nutritional needs and small appetites. Peer pressure and media advertising also influence children’s food preferences. Therefore, it is important that all meals and snacks are energy-rich in nutrients. 

Choices of insulin regimes and types of insulin used may change as a child grows and develops. As no two children are the same, there are many different insulin regimes which may be appropriately used in the management of type 1 in children and adolescents. 

Insulin doses should be tailored for each patient’s individual circumstances and requirements, taking into account age, weight, stage of puberty, duration of diabetes, food intake and distribution, exercise patterns and daily routines. This can be challenging and is dependent on both the multidisciplinary team and the patient. 

MDI and CSII therapy may offer some advantages over other regimes, in that both allow patients more freedom over their diet and choice and timing of foods eaten. They may also have associated disadvantages; however, in that they may be more difficult and time-consuming to administer and require more educational support and may require more frequent blood glucose monitoring.

Adolescence

Treatment of type 1 in puberty is also challenging. Puberty causes a surge in growth hormone and sex steroids, leading to a phase of rapid growth and increase in body mass. This increases insulin resistance and can disrupt a previously successful insulin regime. Good glycaemic control is necessary for optimal growth and sexual maturation, and to reduce the risk of long-term microvascular complications. 

Responsiveness to phases of increased blood sugars and consequently increasing doses of insulin are required during puberty for glycaemic control. Puberty can be a difficult time for any teenager; and this is further increased by the demands of having type 1 diabetes. During adolescence, it is common to see rebellious phases; for some, this may be aimed at their condition. 

Some young people become less compliant with insulin regimes and eating disorders are more common during this developmental period. On the other hand, some young people with type 1 remain diligent in trying to control their diabetes. Type 1 diabetes diagnosed for the first time during adolescence can present a particularly complex challenge for young people.

Exercise

Exercise is an important factor in blood glucose control. Regular physical activity should be encouraged and considered part of the management of type 1 diabetes in children. Indeed, it should be encouraged for all children. Regular physical activity improves aerobic capacity, overall health and muscle strength. 

However, the reported effect on glycaemic control (measured by HbA1c) varies. Hypoglycaemia may occur during exercise and even up to 7-12 hours after exercise. It is worth noting that, depending on the child, the type of activity, and whether the environment is competitive, some children experience hyperglycaemia during or after exercise.⁹

As exercise in children may be planned or unplanned, formal or informal and supervised or unsupervised, the safe integration of exercise into the management of children with type 1 can be challenging. Blood glucose levels should be monitored before, during and after physical activity. 

Patients, parents and carers must be constantly educated about nutritional requirements and insulin doses required to account for physical activity, younger children should be supervised and solo activities should be approached with care. 

Young people who exercise should always carry glucose tablets or some form of rapidly absorbed sugar. Some authors recommend different insulin dose reductions, depending on duration and intensity of exercise. An example for reductions in pre-meal insulin before exercise can be seen in Table 1.¹⁰

The child in the context of the family

As previously highlighted, caring for type 1 requires educating more than just the patient. Usually, the child is accompanied by a parent; so there is almost always more than one person in the consultation room. Extended education provides better results. 

Who may need to receive education? All those who may look after the patient with type 1, including grandparents, teachers, babysitters and friends. If those who look after children better understand the condition, they can educate and improve a child’s glycaemic control from an early age.

When it comes to outpatient visits, as one would expect, the emphasis and aims of care are also likely to be different. Paediatric type 1 clinical care is child-focused and based on knowledge of both the child and their family, their interests and needs and motivating them to aim for better glycaemic control. 

Microvascular and macrovascular complications are more commonly encountered in the adult diabetes clinic. There, the focus is on disease management, management of complications and prevention of further complications. We take all paediatric diabetic clinics as an opportunity to meet with and further educate patients and their parents on good glycaemic control, in order to avoid these long-term complications. 

Diabetic ketoacidosis (DKA)

DKA is more common and more severe in children at presentation than in adults.¹¹ Dehydration occurs more rapidly given the relatively smaller body mass of children. During childhood, more intercurrent illnesses lead to an increased risk of developing DKA, when compared to adults. 

DKA is the most common cause of death in a patient with newly diagnosed type 1 diabetes and the greatest risk of mortality during DKA is due to the development of cerebral oedema. Children are more likely to develop cerebral oedema secondary to severe dehydration, and so DKA poses a much more life-threatening complication in children than it does in adults.¹¹

HbA1c targets in childhood

The most appropriate measure of long-term glycaemic control is glycosylated haemoglobin (HbA1c). There are various recommendations for HbA1c from various professional diabetes groups. The American Diabetes Association recommends higher HbA1c targets for children compared to adults because of the vulnerability to hypoglycaemia as discussed above.¹² This recommendation has been incorporated into the management of diabetic children worldwide (DCCT). 

Target HbA1c values differ by age in the paediatric setting. The International Society of Paediatric and Adolescent Diabetes and The American and Canadian Diabetes Associations set different targets by patient age, as can be seen in Table 2.

Summary 

Children are not small adults. The management of type 1 diabetes in children is complex and adult management strategies cannot be applied to children. Every child is different and managing the condition involves a multidisciplinary approach and constant education and support. 

There may be more than one individual involved in the care of a child, such as parents, siblings, minders and teachers, and to optimise management and glycaemic control, all the above need to be educated on the management of one child’s illness. 

Furthermore, management regimes of children’s type 1 must evolve and change as the child matures and grows.

Complications of type 1 seen in childhood include, most commonly, DKA and hypoglycaemia, and these can have negative effects on brain development and cognitive outcomes in adult life. Severe hypoglycaemia, if it is frequent and begins at an early age, can result in cognitive decline. 

HbA1c targets are not universal in children, and instead are tailored to the child’s age, with the objective of permitting hyperglycaemia to prevent hypoglycaemia. 

Type 1 diabetes is a lifelong condition, children are presenting with the condition in greater numbers and at younger ages, and tend to experience a shorter duration of symptoms than adults at presentation. They tend to be sicker than adults at presentation and require more frequent readmissions to hospital with acute complications.

Perhaps the biggest problem facing children with type 1, their parents and their healthcare team is that children with type 1 become adults with type 1, and they will have long durations of illness, placing them at high risk of long-term complications. 

Therefore multidisciplinary care and education for the child and the family should begin on the day of diagnosis, should be designed to empower both the patient and his/her parents to take control of the management and strive for a better outcome with less complications. 

Orla O’Leary is a paediatric SHO and Anne Quinn is a diabetes nurse specialist at the Mid-Western Regional Hospital, Limerick, and Clodagh O’Gorman is professor of paediatrics at the Graduate Entry Medical School, University of Limerick

References

1. Roche EF, Menon A, Gill D, Hoey H, et al. Clinical presentation of type 1 diabetes. Pediatric Diabetes, 2005; 6(2): 75
2. Patterson CC, Dahlquist GG, Green A, et al. Incidence trends for childhood type 1 diabetes in Europe during 1989-2003 and predicted new cases 2005-20: a multicentre prospective registration study. Lancet 2009; 373: 2027-2033
3. Karjalainen J, Salmela P, IIonen J, et al. A comparison of childhood and adult type 1 diabetes mellitus. N Engl J Med 1989; 320(14): 881-886
4. Sabbah E, Savola K, Kulmala P, et al. Diabetes-associated autoantibodies in relation to clinical characteristics and natural course in children with newly diagnosed type 1 diabetes. The Childhood Diabetes in Finland Study Group. J Endocrinol Metab 1999; 84(5): 1534-1539
5. Economic Social Research Institute. Activity in acute public hospitals in Ireland, 2010 Annual Report. Health Research and Information Division 2011
6. Smith AHK, et al. The National Paediatric Diabetes Audit. Annual Report, 2001: 1-30. Diabetes UK
7. Asvold BO, Sand T, Hestad K, et al. Cognitive function in type 1 diabetic adults with early exposure to severe hypoglycemia: a 16-year follow-up study. Diabetes Care 2010, 33: 1945-1947
8. Hershey T, Lillie R, Sadler M, White NH. Severe hypoglycemia and long-term spatial memory in children with type 1 diabetes mellitus: A retrospective study. J Int Neuropsychol Soc 2003; 9: 740-750 
9. Hanas R, Donaghue KC, Klingensmith G, Swift PG. ISPAD Clinical Practice Consensus Guidelines 2009 Compendium. Introduction. Pediatr Diabetes 2009; 10(12): 1-2
10. Riddell MC, Iscoe KE. Physical activity, sport, and pediatric diabetes. Pediatric Diabetes 2006; 7(1): 60-70
11. Wolfsdorf J, Glaser N, Sperling MA, American Diabetes Association. Diabetic ketoacidosis in infants, children, and adolescents: A consensus statement from the American Diabetes Association. Diabetes care 2006; 29(5): 1150-1159
12. American Diabetes Association. Standards of Medical Care in Diabetes – 2010. Diabetes Care 2010; 33(1): S11-S61.doi: 10.2337/dc10-s011