What blood sugar level is considered low
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Understanding Low Blood Sugar Levels: Definitions and Thresholds
Definition of Low Blood Sugar (Hypoglycemia)
Hypoglycemia, commonly known as low blood sugar, occurs when blood glucose levels fall below the normal range. The exact threshold for what constitutes low blood sugar can vary depending on the context and the population being studied. Generally, hypoglycemia is defined as a blood glucose level that is low enough to cause symptoms and potential harm.
Low Blood Sugar Levels in Newborns
In newborns, particularly full-term normal infants, the definition of low blood sugar varies significantly. A meta-analysis of studies on neonatal hypoglycemia suggests that the threshold for low blood sugar in newborns during the first 72 hours of life can range from less than or equal to 28 mg/dL in the first 1-2 hours, to less than or equal to 48 mg/dL after 48-72 hours . These thresholds are based on the 5th percentile of plasma glucose concentrations observed in full-term normal newborns.
Clinical Significance in Diabetes
For individuals with diabetes, the definition of hypoglycemia is more complex. The American Diabetes Association and the European Association for the Study of Diabetes recommend that glucose concentrations below 3.0 mmol/L (54 mg/dL) be reported in clinical trials as clinically significant biochemical hypoglycemia 25. This threshold is important for identifying and avoiding levels of hypoglycemia that pose immediate and long-term dangers to individuals with diabetes.
General Population Thresholds
In the general population, hypoglycemia is typically defined as a blood glucose level below 70 mg/dL . This threshold is used to identify when blood sugar levels are low enough to potentially cause symptoms such as dizziness, confusion, and even loss of consciousness if not addressed promptly.
Variability in Glycemic Thresholds
It is important to note that the glycemic thresholds for symptoms of hypoglycemia and the body's counterregulatory responses can vary among individuals, especially those with diabetes. Factors such as the individual's HbA1c levels, their history of hypoglycemic episodes, and their overall glycemic control can influence these thresholds 25. Therefore, it is crucial for individuals to work with their healthcare providers to determine their specific targets and thresholds for low blood sugar.
Conclusion
Low blood sugar levels, or hypoglycemia, are defined differently depending on the population and context. In newborns, thresholds range from 28 mg/dL to 48 mg/dL within the first 72 hours of life. For individuals with diabetes, a level below 54 mg/dL is considered clinically significant. In the general population, hypoglycemia is typically defined as a blood glucose level below 70 mg/dL. Understanding these thresholds is essential for managing and preventing the potential dangers associated with low blood sugar.
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