Paediatrics: Type 2 diabetes mellitus

Type 2 diabetes mellitus

T2DM is a multifactorial and heterogeneous condition in which the balance between insulin sensitivity and insulin secretion is impaired. The condition is characterized by hyperinsulinaemia; however, there is relative insulin in-sufficiency to overcome underlying concomitant tissue insulin resistance.

Epidemiology

T2DM is emerging as a significant health problem with increasing incidence in most developing countries. The increasing frequency of T2DM parallels the upward trend in childhood obesity in these populations. In the USA, T2DM now accounts for up to 45% of the new cases of diabetes diagnosed in childhood.

Aetiology

T2DM is not an autoimmune disease. There is no association with HLA-linked genes; however, there is a strong genetic basis, which is thought to be polygenic. The known risk factors for the development of T2DM are as follows.

·  Obesity.

·  Family history of T2DM.

·  Ethnic origin:

·  Asian;

·  African-American;

·  Afro-Caribbean;

·  Pacific-Islander;

·  Mexican-American;

·  Native American.

·  Polycystic ovarian syndrome.

• Small for gestational age (SGA).

Clinical features

Clinical presentation ranges from mild incidental hyperglycaemia to the typical manifestations of insulin deficiency. Presentation with DKA may occasionally be seen. Frequent clinical findings include evidence of obesity and acanthosis nigricans.

Diagnosis

Current diagnostic prerequisites for T2DM are:

·  presence of T2DM risk factors (see list in b ‘Aetiology’ above);

·  lack of absolute/persistent insulin deficiency;

·  absence of pancreatic autoantibodies.

Not infrequently the distinction between T1DM and T2DM at initial pres-entation may be difficult. Management

All patients with T2DM require the same type and degree of educational support and clinical follow-up as for patients with T1DM. Long-term man-agement goals are the same as for T1DM.

Specific treatment goals should in addition include the following:

·aim to improve insulin sensitivity and insulin secretion;

·manage obesity and its comorbidities via lifestyle changes;

·screening and management of T2DM comorbidities such as hyperlipdaemia and hypertension.

Mild (incidental) T2DM should initially be managed with lifestyle inter-ventions aimed at lowering caloric intake (low fat; reduced CHO diet) and increasing physical activity. Where these interventions fail, pharma-cological therapy is added. In children, the oral insulin sensitizing agent metformin is added as a first step; however, if glycaemic targets remain difficult to achieve insulin therapy should be included.