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Diabetes Mellitus

Diabetes mellitus consists of hyperglycemia caused by insulin deficiency, impairment of insulin action, or both. Five percent of the population is affected by diabetes, 10% of whom have type 1 diabetes.

Pathogenesis of type 1 diabetes

Type 1 diabetes develops in individuals who are genetically susceptible, have certain environmental exposures, and have immune-mediated destruction of the beta cells diabetes.

Although 80-85% of patients who have type 1 diabetes have no other affected family member, the relative risk increases to 1 in 20 (from 1 in 300) for first-degree relatives.

Clinical presentation of type 1 diabetes

Classic signs and symptoms of diabetes include polyuria, polydipsia, and polyphagia. Extremely high glucose levels cause a severe diuresis that results.

Long-term diabetes management

Intensive management of diabetes results in a significant reduction in the development of diabetic complications: a 76% reduction in retinopathy, a 39% reduction in microalbuminuria, and a 60% reduction in neuropathy.

 

Insulin regimens

The preferred insulin preparation is human insulin. For preschool- and school-age children, two injections are usually all that is required to achieve targeted glycemia.

Insulin analogs have a more rapid onset of action than regular insulin. Lispro insulin has an onset of action of 10 minutes and a duration of action of 2 hours. The ability to administer lispro 10 minutes prior to eating improves lifestyle. In very young children, it may be given after the meal when the exact quantity of food ingested can be determined.

Blood glucose monitoring. Children and adolescents should test their blood glucose levels at least four times a day, before meals and at bedtime. Additional testing should be performed intermittently, particularly in the middle of the night and at times of unusual behavior in very young children. Quarterly measurement of hemoglobin A1c (HbA1c) assesses glycemic control and reflects the average blood glucose over the last 120 days.

Urinary microalbumin excretion should be assessed with an albumin-to-creatinine ratio yearly, starting five years after diabetes has been diagnosed. If albumin is high--exceeding 30 mg/g on at least two occasions--the adequacy of glycemic control.