What are the recommended treatments for managing diabetes?

Managing Diabetes: A Stepwise Approach

All patients with diabetes should begin with comprehensive lifestyle modifications including at least 150 minutes of moderate-intensity aerobic activity weekly and resistance training twice weekly, combined with medical nutrition therapy targeting 5-7% weight loss for overweight patients, while simultaneously initiating metformin at 500 mg daily (increasing to 2000 mg daily in divided doses) for type 2 diabetes or multiple-dose insulin injections for type 1 diabetes. 1, 2, 3

Foundation: Universal Starting Point for All Patients

Lifestyle Modifications (Required for Everyone)

• Physical activity prescription: At least 150 minutes per week of moderate-intensity aerobic exercise (such as brisk walking) plus resistance training at least twice weekly 1, 2, 3
• Reduce sedentary time: Break up prolonged sitting throughout the day, as this independently improves glycemic control 1, 2
• Nutrition therapy: Emphasize nutrient-dense, high-quality foods while decreasing calorie-dense, nutrient-poor foods 1, 2
• Weight loss target: For overweight or obese patients with type 2 diabetes, aim for at least 5-7% reduction in starting weight, which provides clinical benefits including improved glycemia, blood pressure, and lipids 1, 2, 4
• Diabetes self-management education: All patients require comprehensive education focusing on healthy eating patterns, physical activity, glucose monitoring, and recognition of hypo/hyperglycemia 1, 2, 3

Tobacco Cessation (Critical Safety Measure)

• Advise all patients not to use cigarettes, other tobacco products, or e-cigarettes 5
• Include smoking cessation counseling as a routine component of diabetes care, as smoking increases risk of cardiovascular disease, premature death, and microvascular complications 5
• Pharmacologic therapy combined with counseling is more effective than either alone for motivated patients 5

Type 2 Diabetes: Pharmacologic Algorithm

Step 1: Initial Pharmacologic Therapy

• Start metformin at or soon after diagnosis unless contraindicated, beginning at 500 mg daily and increasing by 500 mg every 1-2 weeks up to an ideal maximum of 2000 mg daily in divided doses 1, 2, 3, 6
• Metformin is preferred due to efficacy, safety, low cost, and potential cardiovascular benefits 1, 2, 3
• Critical exception: If the patient has established atherosclerotic cardiovascular disease, heart failure, or chronic kidney disease, consider adding a GLP-1 receptor agonist or SGLT2 inhibitor at diagnosis 3

Step 2: When to Use Insulin First (Instead of Metformin)

Initiate insulin therapy as first-line treatment in the following situations 1, 2:

• Ketosis or diabetic ketoacidosis present
• Random blood glucose ≥250 mg/dL
• HbA1c >9% (some guidelines suggest >8.5%)
• Severe hyperglycemia with catabolism
• Symptomatic diabetes with polyuria, polydipsia, and weight loss

Step 3: Treatment Intensification

• When to add a second agent: If metformin at maximum tolerated dose does not achieve or maintain HbA1c target over 3 months 1, 2
• Second-line options include: SGLT-2 inhibitors, GLP-1 receptor agonists, sulfonylureas, thiazolidinediones, DPP-4 inhibitors, or basal insulin 1, 2

Type 1 Diabetes: Insulin Management

Insulin Regimen

• Multiple-dose insulin injections (≥3 injections per day) or continuous subcutaneous insulin infusion are required from diagnosis 2, 3
• Use insulin analogs rather than regular insulin to reduce hypoglycemia risk 2, 3
• Patients must learn to match prandial insulin doses to carbohydrate intake, preprandial blood glucose levels, and anticipated activity 2

Glucose Monitoring

• Continuous glucose monitoring systems can significantly reduce severe hypoglycemia risk and should be strongly considered 2, 3

Glycemic Targets and Monitoring

HbA1c Goals

• Target HbA1c <7% for most adults with diabetes, with more stringent targets (such as <6.5%) for selected individuals 1, 2
• Monitor HbA1c every 3 months until target is reached, then at least twice yearly 1, 2
• Treatment goals should be individualized based on age, comorbidities, and hypoglycemia risk 2

Hypoglycemia Management and Prevention

Recognition and Treatment

• Hypoglycemia (plasma glucose <3.9 mmol/L or <70 mg/dL) should be treated with 15-20g of rapid-acting glucose 1, 2
• Confirm blood glucose after 15 minutes and repeat treatment if hypoglycemia persists 2
• Metformin rarely causes hypoglycemia by itself, but risk increases if patients skip meals, drink alcohol, or take other glucose-lowering medications 6

High-Risk Situations

• Educate patients about increased hypoglycemia risk during: fasting for tests or procedures, during or after exercise, and during sleep 1, 2
• Severe or frequent hypoglycemia is an absolute indication for treatment regimen modification 2, 3
• Patients with hypoglycemia unawareness should increase glycemic targets temporarily for several weeks to partially reverse this condition 2, 3

Special Considerations and Precautions

Pre-Exercise Evaluation

• Providers should assess for conditions that might contraindicate certain types of exercise: uncontrolled hypertension, untreated proliferative retinopathy, autonomic neuropathy, peripheral neuropathy, and history of foot ulcers or Charcot foot 5
• Patients with diabetic autonomic neuropathy should undergo cardiac investigation before beginning physical activity more intense than their usual level 5
• High-risk patients should start with short periods of low-intensity exercise and slowly increase intensity and duration as tolerated 5

Diabetic Kidney Disease

• Physical activity does not increase the rate of progression of diabetic kidney disease, and there is no need for specific exercise restrictions in general 5
• Insulin requirements may need adjustment in patients with renal impairment, requiring frequent glucose monitoring 7

Insulin Storage and Handling

• Metformin: Store at 68°F to 77°F (20°C to 25°C) 6
• Insulin preparations: Must appear clear and colorless with no visible particles before use 8, 7
• Do not mix insulin glargine (long-acting insulin) with other insulin preparations as this can alter the action profile 8, 7

Medication Interactions

• Substances that may reduce insulin effectiveness: corticosteroids, diuretics, sympathomimetic agents, thyroid hormones, estrogens, and oral contraceptives 8
• Substances that may increase hypoglycemia risk: ACE inhibitors, fibrates, fluoxetine, MAO inhibitors, salicylates, and sulfonamide antibiotics 8
• Beta-blockers may mask signs of hypoglycemia and either potentiate or weaken glucose-lowering effects 8

Common Pitfalls and How to Avoid Them

• Avoid aggressively targeting near-normal HbA1c levels in patients with advanced disease where such targets cannot be safely reached 2
• Reassess medication regimens every 3-6 months and adjust based on HbA1c, side effects, and patient factors 3
• Do not ignore weight gain concerns with smoking cessation: Recent research demonstrates that weight gain after quitting does not diminish the substantial cardiovascular benefit 5
• Adjust insulin dosing when patients change physical activity or meal patterns to prevent hypoglycemia 8
• In geriatric patients, use conservative dosing with slow titration to avoid hypoglycemia, which may be difficult to recognize in this population 7