Management of Glargine Insulin with Blood Glucose Less Than 100 mg/dL

Rationale for Holding Glargine When BG < 100 mg/dL

The American Diabetes Association defines hypoglycemia as any blood glucose level <70 mg/dL, which represents the initial threshold for counterregulatory hormone release 1
For hospitalized patients, insulin regimens should be reassessed if blood glucose falls below 100 mg/dL to prevent hypoglycemia 1
Fasting glucose levels <100 mg/dL are predictors of hypoglycemia within the next 24 hours 2
Severe hypoglycemia can lead to significant morbidity including cognitive impairment, seizures, coma, and in rare cases, mortality 1

If blood glucose is <100 mg/dL, hold the glargine insulin dose 1
If blood glucose is <70 mg/dL, treat hypoglycemia first before considering any insulin administration 1
Review the overall insulin regimen and consider dose reduction for subsequent doses 2
If fasting blood glucose is consistently <100 mg/dL or if >2 fasting values per week are <80 mg/dL, decrease the glargine dose by 2 units 3
Increase frequency of blood glucose monitoring to ensure recovery and stability 2

Patients with a history of hypoglycemia unawareness may require higher glucose thresholds (>100 mg/dL) before insulin administration 1
Elderly patients and those with renal or hepatic impairment are at higher risk of hypoglycemia and may benefit from more conservative thresholds 1
For hospitalized patients, a target glucose range of 140–180 mg/dL is recommended, making a threshold of 100 mg/dL appropriate for holding insulin 2

Never administer insulin when blood glucose is already in the hypoglycemic range (<70 mg/dL) 1
Avoid relying solely on symptoms to determine if a patient is hypoglycemic; always confirm with blood glucose measurement 1
Do not discontinue basal insulin completely based on a single low reading; instead, adjust the dose appropriately for subsequent administrations 3
When simplifying insulin regimens, particularly in older adults, fasting glucose goals of 90–150 mg/dL are appropriate, supporting the practice of holding insulin when glucose is <100 mg/dL 3