Understanding the Insulin System
Insulin is a hormone produced by the pancreas, specifically by beta cells in the islets of Langerhans. Its primary role is to regulate blood sugar (glucose) levels by allowing cells to absorb glucose from the bloodstream to use for energy or store as glycogen in the liver and muscles. Without insulin, or when insulin isn’t working properly, glucose remains in the bloodstream, leading to elevated blood sugar levels.
Insulin Response
When you eat, especially carbohydrates, glucose enters your bloodstream. In response, your pancreas releases insulin. Insulin helps cells take up glucose, reducing blood sugar levels. In people with insulin sensitivity, this process is smooth. However, if the body becomes insulin resistant (as in type 2 diabetes), the cells don’t respond as effectively, and the pancreas compensates by producing more insulin. Over time, this can lead to elevated blood insulin and glucose levels, a state known as hyperinsulinemia.
Blood Sugar Levels and Diabetes
Here are typical blood sugar ranges and what they indicate:
• Normal fasting blood sugar: 70-99 mg/dL (4-5.5 mmol/L)
• Prediabetes (impaired fasting glucose): 100-125 mg/dL (5.6-6.9 mmol/L)
• Diabetes: ≥126 mg/dL (7 mmol/L) on two separate tests
Another important metric is the HbA1c, which measures average blood glucose levels over the past 2-3 months:
• Normal HbA1c: Below 5.7%
• Prediabetes: 5.7% to 6.4%
• Diabetes: 6.5% or above
Understanding the Difference between Type 1 and Type 2 Diabetes
Type 1 Diabetes:
• Cause: An autoimmune condition where the immune system attacks and destroys the insulin-producing beta cells in the pancreas. This means the body produces little to no insulin, and external insulin is required for life.
• Onset: Typically diagnosed in childhood or adolescence, though it can develop in adults.
• Management: People with type 1 diabetes must take insulin via injections or an insulin pump to control their blood sugar.
Type 2 Diabetes:
• Cause: Characterized by insulin resistance, where the body’s cells do not respond effectively to insulin. Over time, the pancreas may struggle to produce enough insulin to maintain normal blood glucose levels.
• Onset: More common in adults, though increasingly diagnosed in younger people due to lifestyle factors (diet, lack of exercise, obesity).
• Risk factors: Obesity, sedentary lifestyle, poor diet, genetics, high stress levels, and metabolic syndrome.
• Management: Initially managed with lifestyle changes (diet, exercise) and oral medications. In some cases, insulin therapy may be needed.
Both types of diabetes can lead to serious complications if not properly managed, such as cardiovascular disease, nerve damage, kidney failure, and vision loss. However, type 2 diabetes is often preventable or reversible with lifestyle modifications.
Improving insulin sensitivity (via diet, exercise, stress reduction, etc.) is crucial in managing or preventing insulin resistance and type 2 diabetes.