Background information
Prevalence
In Japan, the incidence of type 2 diabetes in children almost doubled from 7.3 per 100 000 between 1976 and 1980 to 13.9 per 100 000 between 1991 and 1995.1 In Taiwan, the incidence has been found to be 8.3 and 12.0 per 100 000 for boys and girls, respectively.2 In First Nation Canadian young people, a 4% prevalence of type 2 diabetes among adolescent girls has been reported,3 in Indigenous Australian children, there was a two–fold increase in the prevalence of type 2 diabetes to 1.3% over the 5–year period from 1989 to 1994.4
In the USA, the SEARCH study showed that the overall prevalence of diabetes was 1.82 per 1000 young people in 2001, with higher rates in older children (2.80 cases per 1000 young people aged between 10 and 19 years) compared to younger children (0.79 cases per 1000 aged between 0 and 9 years). In younger children, type 1 diabetes accounted for more than 80% of diabetes, while in older children, type 2 diabetes accounted for 6% in non–Hispanic white young people and 76% in Native American young people.5
Diagnosis of type 2 diabetes in children and adolescents
The diagnosis is made with the same glucose criteria as those used in adults. It is often difficult to determine the type of diabetes that a child or adolescent may have, and in addition to attempting to differentiate on clinical grounds between type 1 diabetes, type 2 diabetes, secondary diabetes and monogenic forms of diabetes, laboratory investigation with islet and insulin autoantibodies, assessment of residual c–peptide and molecular genetic techniques should be performed when indicated and possible.
Treatment
The treatment goals for type 2 diabetes in children and adolescents are to achieve physical and psychological well–being and long–term blood glucose control, and prevent micro–vascular complications and macro–vascular disease. There is limited evidence as to the best treatment modalities for type 2 diabetes, although many more children and adolescents with the condition appear to require insulin therapy than adults.
Lifestyle counselling is important. However, the role of lifestyle alterations and optimum blood glucose targets for treatment are not known. It appears that children and their families need the involvement of a multidisciplinary team, ongoing healthcare visits, perhaps quarterly, and family–centred education where these are possible.
Co–morbidities and complications
The available data as to the long–term complications of type 2 diabetes in young people underscore the severity of the disease. In Japan, it was reported that after 30 years of type 2 diabetes, 44% of those diagnosed when they were under 30 years of age had kidney disease (nephropathy).6 In the Native American Pima community, those diagnosed with type 2 diabetes under 20 years of age were found to have nephropathy at a rate of 13 per 1000 person years.7
In a study of 164 First Nation Canadians with early–onset type 2 diabetes, 69 were followed into adulthood – a mean age of 23, with 9 years duration of diabetes. The mortality rate was 9%, 35% had microalbuminuria, 6% required dialysis, 45% had hypertension requiring treatment, 38% of the women who had become pregnant had pregnancy loss. Over the follow–up period, 35% were lost to clinical follow–up and of those followed, 67% had poor blood glucose control with an average HbA1c of 10.9%.8
In Australia, a study compared outcomes in young people with type 1 diabetes to those with type 2 diabetes. It was found that young people with type 2 diabetes had significantly higher rates of microalbuminuria and hypertension, despite a shorter duration of diabetes and lower HbA1c.9
Screening
The value of screening asymptomatic young people for type 2 diabetes depends on rates of prevalence of the disease in different regions of the world, cost–effectiveness and available screening methods.
