What is the target range for blood sugar levels in individuals with diabetes?

Target Blood Sugar Ranges for Individuals with Diabetes

For most nonpregnant adults with diabetes, target a preprandial (fasting) blood glucose of 80-130 mg/dL and peak postprandial glucose <180 mg/dL, with an A1C goal <7.0%. 1

Outpatient Target Ranges

Standard Targets for Most Adults with Diabetes

• Preprandial (fasting) glucose: 80-130 mg/dL (4.4-7.2 mmol/L) 1
• Peak postprandial glucose (1-2 hours after meals): <180 mg/dL (10.0 mmol/L) 1
• A1C target: <7.0% (53 mmol/mol) 1

The 2015 change from 70-130 mg/dL to 80-130 mg/dL for the lower preprandial target was intentional—it provides a safety margin to prevent overtreatment and hypoglycemia while patients titrate insulin or other glucose-lowering medications. 1

Time in Range (TIR) Targets Using Continuous Glucose Monitoring

For patients using CGM technology, the consensus targets are more granular: 1

• Target range: 70-180 mg/dL (3.9-10.0 mmol/L) 1
• Time in range goal: >70% of readings (>16 hours, 48 minutes per day) 1
• Time below range (<70 mg/dL): <4% of readings (<1 hour per day) 1
• Time above range (>180 mg/dL): <25% of readings (<6 hours per day) 1

Each 5% increase in time in range correlates with clinically significant benefits for both type 1 and type 2 diabetes. 1

Modified Targets for Older or High-Risk Individuals

For older adults or those at high risk for hypoglycemia, relax targets to achieve time in range >50% (>12 hours per day) in the 70-180 mg/dL range, with stricter limits on hypoglycemia (<1% time below 70 mg/dL, which equals <15 minutes per day) and accept higher glucose levels up to 250 mg/dL for <10% of the time. 1

The American College of Physicians provides A1C-based ranges stratified by patient characteristics: 1

• Life expectancy >10-15 years with minimal complications: A1C 6.0-7.0% (if safely achievable) 1
• Established micro/macrovascular disease or 5-10 year life expectancy: A1C 7.0-8.5% 1
• Life expectancy <5 years or significant comorbidities: A1C 8.0-9.0% 1

Inpatient Target Ranges

Critically Ill Patients (ICU)

Initiate insulin therapy when blood glucose persistently exceeds 180 mg/dL (10.0 mmol/L) on two occasions, then target 140-180 mg/dL (7.8-10.0 mmol/L) for most critically ill patients. 1

More stringent targets of 110-140 mg/dL (6.1-7.8 mmol/L) may be appropriate for select patients such as post-cardiac surgery, but only if achievable without significant hypoglycemia. 1 The NICE-SUGAR trial definitively showed that intensive targets (80-110 mg/dL) increase mortality compared to moderate targets (140-180 mg/dL), with 10- to 15-fold higher hypoglycemia rates. 1

Non-Critically Ill Hospitalized Patients

Target preprandial glucose <140 mg/dL (7.8 mmol/L) and random glucose <180 mg/dL (10.0 mmol/L) for general medicine and surgery patients. 1

An acceptable broader range of 100-180 mg/dL (5.6-10.0 mmol/L) applies to most non-critical inpatients, though fasting glucose <100 mg/dL predicts hypoglycemia risk within 24 hours. 1 For terminally ill patients or those with severe comorbidities, glucose levels up to 250 mg/dL (13.9 mmol/L) may be acceptable to minimize treatment burden. 1

Hypoglycemia Thresholds (What to Avoid)

Understanding hypoglycemia levels is critical for setting safe targets: 1

• Level 1 (alert value): <70 mg/dL but ≥54 mg/dL (3.9-3.0 mmol/L) - requires treatment with fast-acting carbohydrates 1
• Level 2 (clinically significant): <54 mg/dL (3.0 mmol/L) - neuroglycopenic symptoms begin, requires immediate action 1
• Level 3 (severe): altered mental/physical status requiring assistance - medical emergency 1

Treat hypoglycemia at 70 mg/dL or below with approximately 15-20 grams of glucose, recheck in 15 minutes, and repeat treatment if needed. 1

Key Clinical Pitfalls

• Avoid the lower limit of 70 mg/dL as a target—the shift to 80 mg/dL provides necessary safety margin 1
• Individualization is mandatory but follows a pattern: tighter control (lower A1C, narrower ranges) for newly diagnosed patients with long life expectancy and no complications; relaxed control for those with established complications, hypoglycemia unawareness, or limited life expectancy 1
• Postprandial targets matter when A1C goals aren't met despite achieving preprandial targets 1
• CGM coefficient of variation should be <36% to minimize hypoglycemia risk in insulin-treated patients 1