Goal Fasting Blood Glucose for People with Diabetes
For most nonpregnant adults with diabetes, the goal fasting blood glucose is 80-130 mg/dL (4.4-7.2 mmol/L). 1
Standard Targets for Nonpregnant Adults
The American Diabetes Association establishes clear preprandial (fasting) glucose targets that have remained consistent across multiple guideline iterations:
- Preprandial capillary plasma glucose: 80-130 mg/dL (4.4-7.2 mmol/L) for the majority of nonpregnant adults with diabetes 1
- This target correlates with achieving an A1C <7% (53 mmol/mol), which is the primary glycemic goal 1
- Peak postprandial glucose should remain <180 mg/dL (10.0 mmol/L) when measured 1-2 hours after beginning a meal 1, 2
When to Individualize Targets
While 80-130 mg/dL is the standard, you should adjust this target based on a systematic assessment of patient factors 1:
More Stringent Goals (targeting lower end of 80-130 mg/dL or even 70-120 mg/dL):
- Newly diagnosed diabetes with short disease duration 1
- Long life expectancy 1
- Absent or minimal comorbidities 1
- No history of severe hypoglycemia or hypoglycemia unawareness 1
- Highly motivated patients with excellent self-care capabilities 1
Less Stringent Goals (targeting higher end of range or even >130 mg/dL):
- Long-standing diabetes with established complications 1
- Limited life expectancy 1
- Severe comorbidities present 1
- History of severe hypoglycemia or hypoglycemia unawareness 1
- Advanced age with functional or cognitive impairments 1
- Patient preference for less burdensome therapy 1
Special Population Targets
Hospitalized Patients (Critically Ill):
- Initiate insulin therapy when glucose persistently ≥180 mg/dL (10.0 mmol/L) 1
- Target range: 140-180 mg/dL (7.8-10.0 mmol/L) for most critically ill patients 1
- More stringent goals of 110-140 mg/dL (6.1-7.8 mmol/L) may be appropriate for selected patients (e.g., post-cardiac surgery) only if achievable without significant hypoglycemia 1
Hospitalized Patients (Non-Critically Ill):
- Target range: 100-180 mg/dL (5.6-10.0 mmol/L) for noncritically ill patients 1
- Premeal targets generally <140 mg/dL (7.8 mmol/L) if treated with insulin 1
Gestational Diabetes:
- Fasting plasma glucose <95 mg/dL (5.3 mmol/L) 1
- This is significantly more stringent than targets for non-pregnant adults 1
Critical Pitfalls to Avoid
Do not rely solely on fasting glucose to assess control. If A1C goals are not met despite achieving preprandial targets, you must check postprandial glucose values to identify excessive postprandial excursions 1, 2
Avoid overly aggressive targets in high-risk patients. The NICE-SUGAR trial demonstrated that targeting glucose <110 mg/dL in critically ill patients increased mortality compared to more moderate targets of 140-180 mg/dL 1
Do not ignore hypoglycemia risk. Fasting glucose <100 mg/dL predicts hypoglycemia within the next 24 hours in hospitalized patients 1. Any target must balance glycemic control against hypoglycemia risk, which is the major limiting factor in diabetes management 1
Practical Implementation
Monitor fasting glucose frequency based on treatment regimen 1:
- Patients on multiple daily insulin injections: At least 4 times daily (including fasting) 1
- Patients on basal insulin only: Daily fasting checks are typically sufficient
- Patients on non-insulin therapy: Frequency should be sufficient to facilitate reaching glucose goals, though optimal frequency is not definitively established 1