Hypoglycemia is a condition associated with low blood sugar levels. This is often related to the treatment of diabetes.
The medications associated with hypoglycemia are insulin, sulfonylureas, meglitinides. Within sulfonylureas, hypoglycemia is more common with long-acting drugs, such as glyburide (glibenclamide), compared with the shorter-acting glipizide, glimepiride, and gliclazide.
The lower limit of the normal fasting plasma glucose value is typically 70 mg/dL (3.9 mmol/L).
The risk factors of hypoglycemia are erratic timings of meals, missed meals, the low carbohydrate content of the meals, alcohol ingestion, chronic kidney disease, longer duration of diabetes, older age, a higher dose of medications.
Classification of severity of hypoglycemia based on the American diabetes association (ADA) is as follows:
- Severe hypoglycemia is defined as an event that requires the active assistance of other people to administer carbohydrate, glucagon, or other resuscitative actions.
- Documented symptomatic hypoglycemia – The event with symptoms of hypoglycemia accompanied by glucose measurement of ≤70 mg/dL (3.9 mmol/L)
- Asymptomatic hypoglycemia – There are no typical symptoms of hypoglycemia during an event but the measured glucose level ≤70 mg/dL (3.9 mmol/L).
- Pseudohypoglycemia – There are typical symptoms of hypoglycemia during an event but has a measured glucose level >70 mg/dL (3.9 mmol/L). This happens in patients with chronically poorly controlled diabetes.
Strategies to prevent hypoglycemia
- Talk to your doctor on how to adjust the medications, meal plan, exercise based on the glucose patterns.
- Regular self-monitoring of blood glucose (SMBG) is critical to the glycemic management of intensively treated (basal/bolus insulin) diabetes mellitus. Patients with asymptomatic hypoglycemia due to repeated episodes of hypoglycemia and/or impaired awareness of hypoglycemia may benefit from continuous glucose monitors (CGM). Glycemic patterns need to be identified by self-monitoring of blood glucose levels periodically before and two to three hours after each meal, bedtime, in the middle of the night, and before and after exercise.
- Close associate, spouse or family members need to be educated on how to treat developing hypoglycemia with oral carbohydrate or glucagon.
- Patients are advised to carry fast-acting carbohydrates with them all the time. Quick sources of sugar are soda, juice, raisins, hard candies, glucose tablets.
- Exercise increases glucose utilization by muscle and can cause hypoglycemia in a patient with near-normal or moderately elevated plasma glucose levels at the start of the exercise. Interspersing brief episodes of intense exercise, adding carbohydrate ingestion (eg, 1 g/kg/h), and reducing insulin doses reduce early post-exercise hypoglycemia
Management of hypoglycemia – The goal of treatment is to reverse hypoglycemia and raise the plasma glucose levels to normal concentration by administering carbohydrate (glucose) or in severe cases glucagon.
Asymptomatic hypoglycemia – Ingesting carbohydrate, repeating the measurement within 15 to 60 minutes (depending on the setting), avoid driving, adjust the treatment regime.
Symptomatic hypoglycemia – Ingest 15 to 20 grams of fast-acting carbohydrate ( hard candies, soda, glucose tablets, raisins, etc). Retest the blood glucose levels after 15 minutes. If the blood glucose level remains ≤70 mg/dL (3.9 mmol/L), repeat the treatment. The patient should have a long-acting carbohydrate meal or snack to prevent recurrent symptoms.
Please note that the patients taking insulin or insulin secretagogue (sulfonylureas and glinides) in combination with an alpha-glucosidase inhibitor (acarbose, voglibose, miglitol) only pure glucose or glucose tablets should be used to treat symptomatic hypoglycemia. Alpha-glucosidase inhibitors slow digestion of disaccharides and so other forms of carbohydrates will be less effective in raising the blood glucose levels.
Severe hypoglycemia is treated by another person actively by administering carbohydrate, glucagon, or other resuscitative measures.
Patients in the hospital with the IV access are treated by giving 25 g of 50 percent glucose (dextrose) intravenously (IV). The glycemic response to IV glucose is transient and this treatment should be followed by a continuous infusion of glucose or food if the patient is able to eat.
Patients with no IV access and impaired consciousness are treated with glucagon if available. Glucagon is administered nasally, subcutaneous, or intramuscular. Patients will regain consciousness within 15 minutes of administration although they may experience nausea or vomiting. The glycemic response to IV glucose is transient and this treatment should be followed by a continuous infusion of glucose or food if the patient is able to eat.
Patients with no IV access, impaired consciousness, and glucagon are not available are treated by squeezing the glucose gel or by sprinkling table sugar under the tongue, keeping the patient’s head tilted slightly to the side while awaiting emergency personnel.