What are the treatment guidelines for Diabetes Mellitus (DM)?

Diabetes Mellitus Treatment Guidelines

Initial Pharmacologic Management

For newly diagnosed type 2 diabetes, metformin combined with lifestyle modifications (at least 150 minutes of moderate-intensity aerobic activity weekly, reduced calorie intake for weight loss) should be initiated at or soon after diagnosis unless contraindicated. 1, 2 Metformin is inexpensive, has long-established efficacy and safety data, and may reduce cardiovascular events and death. 1

When to Add Second-Line Therapy

• Add a second agent when monotherapy fails to achieve or maintain HbA1c target over 3 months. 1
• For patients with inadequate glycemic control on metformin, add either an SGLT-2 inhibitor or GLP-1 receptor agonist to reduce mortality and morbidity. 3

Medication Selection Algorithm for Type 2 Diabetes

Prioritize based on comorbidities: 3

• Heart failure present: SGLT-2 inhibitor (reduces hospitalization for congestive heart failure) 3
• Chronic kidney disease: SGLT-2 inhibitor 3
• High stroke risk: GLP-1 receptor agonist (reduces stroke) 3
• DPP-4 inhibitors are NOT recommended as add-on therapy due to lack of mortality benefit 3

Critical safety consideration: When adding SGLT-2 inhibitor or GLP-1 agonist, reduce or discontinue sulfonylureas or long-acting insulins to avoid hypoglycemia. 3 This is a common pitfall that leads to severe hypoglycemic episodes.

Type 1 Diabetes Management

Most patients with type 1 diabetes should be treated with multiple daily injections (≥3 injections daily) of basal/bolus insulin or continuous subcutaneous insulin infusion. 1, 4 This approach has demonstrated clear improvements in microvascular complications and cardiovascular disease risk. 1

Insulin Regimen Specifics

• Basal insulin: Use long-acting insulin analogues (glargine or detemir) once or twice daily rather than NPH insulin to reduce hypoglycemia risk, especially nocturnal episodes 1, 4, 5
• Prandial insulin: Use rapid-acting insulin analogues (lispro, aspart, or glulisine) 0-15 minutes before meals rather than regular human insulin 1, 4, 5
• Patients should match prandial insulin doses to carbohydrate intake, preprandial blood glucose levels, and anticipated activity. 1

Glycemic Targets

Target HbA1c <7.0% (53 mmol/mol) for most nonpregnant adults to decrease microvascular complications. 1, 2 However, targets must be individualized based on: 1, 2

• Duration of diabetes: Longer duration may warrant less stringent targets
• Age: Older adults (>65 years) should target HbA1c 7-8% 1, 3
• Comorbidities and life expectancy: Less stringent targets for limited life expectancy 1
• Hypoglycemia risk: Higher targets for those with hypoglycemia unawareness 1

For type 1 diabetes in children, target HbA1c <7.5% (58 mmol/mol). 4

Monitoring Protocol

• Monitor HbA1c every 3 months until target achieved, then at least twice yearly. 2
• Self-monitoring of blood glucose (SMBG) is essential for patients on insulin or at hypoglycemia risk. 2
• Continuous glucose monitoring should be considered for type 1 diabetes patients to reduce severe hypoglycemia risk. 1
• For type 2 diabetes on metformin plus SGLT-2 inhibitor or GLP-1 agonist, routine SMBG may be unnecessary. 3

Hypoglycemia Management

Moderate hypoglycemia is defined as blood glucose <70 mg/dL; severe hypoglycemia as <54 mg/dL. 1

Treatment Protocol

• Administer 15-20 grams of rapid-acting glucose (pure glucose preferred). 1
• Recheck blood glucose after 15 minutes; repeat treatment if hypoglycemia persists. 1
• For patients without IV access or unable to take oral glucose, use intranasal or subcutaneous glucagon. 1
• After any hypoglycemic episode, review and modify treatment regimens, particularly reducing or avoiding sulfonylureas and insulins. 1

Hypoglycemia Unawareness

Patients with hypoglycemia unawareness should increase glycemic targets for several weeks to partially reverse the condition and reduce future episode risk. 1

Cardiovascular Risk Management

Blood Pressure Targets

**Target systolic BP to 130 mmHg and <130 mmHg if tolerated, but not <120 mmHg.** 1, 2 For older adults (>65 years), target systolic BP 130-139 mmHg. 1

Target diastolic BP <80 mmHg but not <70 mmHg. 1

• Initiate treatment with RAAS blocker (ACE inhibitor or ARB) combined with calcium channel blocker or thiazide/thiazide-like diuretic. 2
• Do NOT combine ACE inhibitor with ARB. 1

Lipid Management

For type 2 diabetes patients at very high cardiovascular risk, target LDL-C <1.4 mmol/L (<55 mg/dL) with at least 50% LDL-C reduction. 1, 2

For high cardiovascular risk, target LDL-C <1.8 mmol/L (<70 mg/dL) with at least 50% reduction. 1

For moderate cardiovascular risk, target LDL-C <2.6 mmol/L (<100 mg/dL). 1

• Statins are first-choice lipid-lowering treatment. 2

Antiplatelet Therapy

Aspirin (75-100 mg/day) for primary prevention may be considered in patients at very high/high cardiovascular risk without clear contraindications. 1

Aspirin is NOT recommended for primary prevention in moderate cardiovascular risk patients. 1

Screening for Complications

Nephropathy

Test for albuminuria at diagnosis of type 2 diabetes and annually thereafter if previously negative. 2 Microalbuminuria identifies patients at risk for renal dysfunction and high cardiovascular disease risk. 2

Retinopathy

Conduct regular eye examinations with frequency determined by risk factors and previous findings. 2

Cardiovascular Disease

Resting ECG is recommended in patients with hypertension or suspected cardiovascular disease. 1

Consider carotid or femoral ultrasound for plaque detection as cardiovascular risk modifier. 1

Special Populations

Older Adults

• Less stringent glycemic targets (HbA1c 7-8%) are appropriate based on functional status and life expectancy. 1, 3
• Deintensify pharmacologic treatments when HbA1c <6.5%. 3
• Avoid aggressive attempts to achieve near-normal HbA1c in patients with advanced disease. 1
• Screen for depression during initial evaluation and with any unexplained clinical decline. 2
• Therapeutic diets should be tailored to culture, preferences, and personal goals to avoid unintentional weight loss and undernutrition. 1

End-of-Life/Palliative Care

Overall comfort, prevention of distressing symptoms (pain, hypoglycemia, hyperglycemia, dehydration), and preservation of quality of life are primary goals. 1

• Glucose targets should prevent both hypoglycemia and symptomatic hyperglycemia rather than achieving tight control. 1
• Consider withdrawing or simplifying treatment; oral agents may be first-line followed by simplified basal insulin regimen without rapid-acting insulin. 1
• Reduce frequency of fingerstick testing based on goals of care. 1

Inpatient Hyperglycemia Management

For non-critically ill hospitalized patients, use scheduled basal, prandial, and correction insulin rather than sliding scale insulin alone. 1

Target blood glucose 140-180 mg/dL for most hospitalized patients. 1

• For stable patients eating regularly, consider continuing prehospitalization oral antihyperglycemic medications or insulin regimens. 1
• Avoid SGLT-2 inhibitors in hospitalized patients. 1
• Sliding scale insulin alone is NOT recommended except in very specific circumstances (HbA1c <7%, mild hyperglycemia, tapering steroids, or high hypoglycemia risk). 1

Transitions of Care

Arrange outpatient follow-up within 1 week to 1 month after discharge, preferably with primary care or diabetes specialist. 1

Provide discharge education covering: 1

• Medication review (purpose, administration, side effects)
• Blood glucose monitoring
• Hypoglycemia prevention
• Nutrition

Provide medications at discharge, specifically insulin, along with monitoring materials (test strips, lancets, hypoglycemia kits). 1

Metformin in Renal Impairment

Metformin can be continued with declining renal function down to GFR 30-45 mL/min, though dose should be reduced. 1 This represents updated guidance allowing broader use than previously recommended.