5-Minute Clinical Consult

Hypoglycemia, Diabetic

Hypoglycemia, Diabetic was found in 5-Minute Clinical Consult which helps you diagnose, treat, and follow up on over 900 medical conditions seen in everyday practice.

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  • Abnormally low concentration of glucose in circulating blood of a patient with diabetes; often referred to as an insulin reaction
  • Classification includes:
    • Severe hypoglycemia: An event requiring assistance of another person to actively administer treatment
    • Documented symptomatic hypoglycemia: An event during which typical symptoms are accompanied by a measured plasma glucose of <70 mg/dL (3.9 mmol/L)
    • Asymptomatic hypoglycemia: An event not accompanied by symptoms, but a measured glucose of <70 mg/dL (3.9 mmol/L)
    • Probable symptomatic hypoglycemia: Event with symptoms, but glucose not tested
    • Relative hypoglycemia: An event with typical symptoms, but glucose ≥70 mg/dL (3.9 mmol/L)
  • Hypoglycemia is the leading limiting factor in the glycemic management of type 1 and type 2 diabetes. Severe or frequent hypoglycemia requires modification of treatment regimens, including higher treatment goals.
Hypoglycemic unawareness:
  • Major risk factor for severe hypoglycemic reactions
  • Most commonly found in patients with long-standing type 1 diabetes and children age <7 years


  • From the Accord Study, the annual incidence of hypoglycemia was:
    • 3.14% in the intensive treatment group
    • 1.03% in the standard group
    • Increased risk among women, African Americans, those with less than a high school education, aged participants, and those who used insulin at trial entry
  • From the RECAP-DM study: Hypoglycemia was reported in 38% of patients with type 2 diabetes who added a sulphonylurea or thiazolinedione to metformin therapy during the past year.

Etiology and Pathophysiology

  • Loss of hormonal counter-regulatory mechanism in glucose metabolism
  • Diet: Too little food (skipping meal), decreased carbohydrate intake
  • Medication: Too much insulin or oral hypoglycemic agent (improper dose or timing)
  • Erratic absorption of insulin or oral hypoglycemics
  • Adverse reaction from other medications
  • Exercise/physical activity: Unplanned or excessive
  • Alcohol consumption
  • Vomiting or diarrhea
  • Gastroparesis

Risk Factors

  • Nearly 3/4 of severe hypoglycemic episodes occur during sleep
  • Autonomic neuropathy
  • Illness, stress, and unplanned life events
  • Duration of diabetes >5 years, advanced age, renal/liver disease, congestive heart failure (CHF), hypothyroidism, hypoadrenalism, gastroenteritis, gastroparesis (unpredictable CHO delivery)
  • Starvation or prolonged fasting
  • Alcoholism: Evening consumption of alcohol is associated with an increased risk of nocturnal and fasting hypoglycemia, especially in patients with type 1 diabetes.
  • Current smokers with type 1 diabetes
  • Oral hypoglycemics with long duration and high potency have greater hypoglycemic risks.
  • Insulin secretagogues: Sulfonylureas (glipizide, glibenclamide, glibornuride, gliclazide, chlorpropamide, glimepiride) and glinide derivatives (repaglinide, Nateglinide) stimulate insulin secretion and can cause hypoglycemia. Hypoglycemia is rare in diabetics not treated with insulin or insulin secretagogues.
  • Severe hypoglycemia is associated with comorbid conditions in patients age ≥65 years and in users of a long-acting sulphonylurea.
  • Intensive insulin therapy (further lowering A1C from 7% to 6%) is associated with higher rate of hypoglycemia.
  • Gastroparesis causing unpredictable carbohydrate delivery predisposes to hypoglycemia.

General Prevention

  • Maintain routine schedule of diet, medication, and exercise.
  • Stabilize daily carbohydrate intake.
  • Regular blood glucose testing, if taking insulin or insulin secretagogue:
    • ≥3× daily testing if multiple injections of insulin, insulin pump therapy, or pregnant diabetic; frequency and timing dictated by needs and treatment goals
    • Particularly helpful for asymptomatic hypoglycemia
  • Diabetes treatment and teaching programs (DTTPs) especially for high-risk type 1 patients, which teach flexible insulin therapy to enable dietary freedom
  • Use of rapid-acting and long-acting insulin analogs is associated with less hypoglycemia (1)[C].
  • Hypoglycemia rates are reduced by up to 70% using continuous SC insulin infusion pumps compared with multiple daily injections (1)[C].
  • Continuous glucose monitoring may supplement self-glucose monitoring and is especially useful with hypoglycemic unawareness and/or frequent hypoglycemic episodes (1)[C].
  • If pre-exercise glucose is <100 mg/dL and taking insulin or secretagogue, then carbohydrate consumption or reduction in medication may prevent hypoglycemia (1)[C].

Commonly Associated Conditions

  • Autonomic dysfunction
  • Neuropathies
  • Cardiomyopathies
  • Older type 2 diabetics with severe hypoglycemia have a higher risk of dementia (2).

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