Intensive glucose control in the management of diabetes mellitus and inpatient hyperglycemia

Abstract

Purpose: The current evidence on intensive glycemic control in the inpatient and outpatient settings and its implications to practice are reviewed.

Summary: Poor glycemic control in patients with diabetes is associated with microvascular and macrovascular complications. Various clinical trials involving patients with type 1 and type 2 diabetes have revealed the benefits of intensive glycemic control in delaying the onset and progression of microvascular complications of diabetes. However, while long-term epidemiologic trials and a meta-analysis have shown a benefit of intensive glycemic control in reducing the incidence of macrovascular complications, recent clinical trials have not found similar benefits. The American Diabetes Association (ADA), American College of Endocrinology (ACE), and American Association of Clinical Endocrinologists recommend intensive control of glycosylated hemoglobin and plasma glucose at specified goals. Hyperglycemia in the inpatient setting is associated with increased morbidity and mortality. ACE and ADA recommend the use of an i.v. insulin infusion in critically ill inpatients with hyperglycemia. In noncritically ill inpatients, basal and bolus doses of insulin are recommended. The use of sliding-scale insulin as the sole therapy for inpatient hyperglycemia is discouraged. However, caution must be exercised to ensure a balance between controlling hyperglycemia and reducing the risk of hypoglycemia.

Conclusion: While intensive glycemic control is known to prevent or delay the occurrence of microvascular complications of diabetes, macrovascular benefits are still uncertain. Current evidence suggests that intensive glycemic control should be initiated as soon as possible after diagnosis of type 1 or type 2 diabetes in order to maximize potential long-term macrovascular benefits. Inpatient hyperglycemia should be managed appropriately to reduce morbidity and mortality, with great care taken to avoid and appropriately treat hypoglycemia.