Diabetes mellitus

• Diabetes mellitus is a chronic hyperglycaemia state, caused by defects in: ◦ insulin secretion ◦ insulin action ◦ both. • Type 1 diabetes accounts for ~95% of cases. ◦ Rising incidence in UK (25/100,000 children/year) now appears to be stabilizing. ◦ Peaks at younger age (4–6 years of age) and also puberty. • Therapy: ■ With subcutaneous insulin (multiple daily injections, continuous subcutaneous insulin infusion (CSII) (less used now, twice- and thrice-daily mixtures)) to mimic physiological secretion, maintain euglycaemia, minimize hypoglycaemic episodes and diabetic ketoacidosis. ◦ Monitoring: ■ Minimum of five self-monitored blood glucose measurements a day recommended. Continuous glucose monitoring increasingly utilized, especially with CSII. ■ Overall control assessed using glycated haemoglobin. • Outcome: ■ Clear evidence that good diabetic control associated with reduction in complications (micro- and macrovascular). ■ Screening recommended at an early stage to detect complications and prevent progression. • Type 2 diabetes: ◦ Increasingly recognized in children/adolescents. ◦ Increased incidence in: ■ females ■ ethnic minorities ■ overweight/obese ■ those with family history. ◦ Part of metabolic syndrome: T2DM/insulin resistance, hypertension, hyperlipidaemia, cardiovascular disease, adrenarche/polycystic ovarian syndrome. ◦ A combination of insulin resistance and (relative) insulin deficiency; oral hypoglycaemics may be appropriate (at least initially). • Other forms of diabetes (uncommon): ◦ Maturity-onset diabetes of the young (MODY): ■ autosomal dominant inheritance; dependent on type, variable ■ response to oral hypoglycaemics ■ development of microvascular complications. ◦ Association with syndromes, e.g. Wolfram, Walcott–Rallison, Prader–Willi syndrome. ◦ Cystic fibrosis-related diabetes: ■ not autoimmune in origin, due to combination of insulin deficiency/resistance ■ increasing incidence with age ■ treatment is with insulin.