Treatment of Hyperglycemia in Type 2 Diabetes

Initial Treatment Strategy

• The American Diabetes Association recommends metformin 500-2000 mg daily as the first-line treatment for hyperglycemia in type 2 diabetes, initiated at diagnosis alongside lifestyle modifications, with insulin therapy reserved for severe hyperglycemia 1, 2
• Metformin should be started at 500 mg once daily with gradual titration to minimize gastrointestinal side effects, increasing to a maximum of 2000 mg daily in divided doses 1, 3, 4
• Metformin reduces A1C by approximately 1-2% and may reduce cardiovascular events and mortality 1, 4

Insulin Therapy

• Insulin therapy is mandatory and should not be delayed when patients present with random glucose consistently >300 mg/dL, A1C ≥10%, or catabolic features 1, 2, 5
• Basal insulin should be started at 10 units daily or 0.1-0.2 units/kg/day using glargine, detemir, or degludec 1, 2
• Mealtime insulin should be started at 4 units per meal or 10% of basal dose if postprandial hyperglycemia persists 2

Combination Therapy

• When metformin monotherapy fails to achieve A1C targets after 3 months at maximum tolerated dose, add a second agent 1, 3, 4
• For patients with established cardiovascular disease, heart failure, or chronic kidney disease, add GLP-1 receptor agonist or SGLT2 inhibitor with proven cardiovascular benefit 1, 3
• GLP-1 receptor agonists are preferred over insulin when possible due to weight loss benefits and low hypoglycemia risk 1, 3

Transition Strategy

• Once severe hyperglycemia is controlled with insulin, taper insulin partially or entirely and transition to oral agents in combination 2, 5

Critical Implementation Pitfalls to Avoid

• Do not delay treatment intensification - recommendations for adding agents should not be postponed when targets are not met 1, 3
• Do not use sliding-scale insulin alone - scheduled basal-bolus regimens are superior 6
• Check renal function before starting metformin and periodically thereafter; dose reduction may be needed with reduced kidney function 4
• Monitor vitamin B12 levels with long-term metformin use, especially if anemia or neuropathy develops 4

Dosing Summary