Lesson 7 of 7 / Nutrition in humans
Type 2 diabetes and glucose control
Why can glucose remain high even when insulin is present?
In this lesson: Explain type 2 diabetes, its risk factors and broad management approaches.
About 5 min
The key ideaType 2 diabetes involves persistently high blood glucose because cells respond less effectively to insulin, insulin supply is insufficient, or both.
Brown circles: glucose. Blue triangles: insulin. Arrow: effect on uptake. Symbols are illustrative; counts are not biological measurements.
Risk factors change likelihood. This schematic cannot diagnose diabetes or choose a treatment.
With adequate insulin and responsive targets, uptake and storage help correct a glucose rise. This is a qualitative comparison, not a diagnostic glucose trace.
Explanation
Insulin resistance means that target cells respond less effectively to insulin. The pancreas may initially produce more insulin, but this may not be enough to maintain normal blood glucose. Insulin production may also become insufficient. The resulting high blood glucose is persistent, rather than just a normal short rise after a meal.
Risk is influenced by several factors. A sedentary lifestyle, excess body fat and an unhealthy dietary pattern can increase risk. Age and family history also matter. A risk factor changes the likelihood of a condition; it does not prove that a person will develop it or explain every individual case.
Management aims to keep blood glucose within an appropriate range and reduce complications. Broad approaches include a balanced eating pattern, regular physical activity, monitoring and medicines prescribed by a healthcare professional when needed. Some people with type 2 diabetes need insulin; others use different management approaches.
For an examination explanation, connect the mechanism to the condition: reduced insulin response or insufficient insulin means glucose uptake and storage are not adequately regulated. Avoid claiming that eating one sugary food causes diabetes, or that all diabetes has the same cause. These are syllabus principles, not a way to diagnose an individual from a graph or symptom.
Step by step
- 1
Describe the control problem
Use reduced insulin response and/or insufficient insulin, not simply "no insulin".
- 2
Connect mechanism to glucose
Less effective regulation of uptake and storage allows glucose to remain high.
- 3
Separate risk from certainty
State broad risk and management factors without diagnosing or blaming an individual.
Worked example
Insulin is present
A teaching case describes persistently high glucose despite insulin being present. Explain why this can occur in type 2 diabetes.
One way to explain it
Target cells may be insulin resistant, so they respond less effectively. The available insulin may therefore be insufficient to regulate glucose uptake and storage adequately, leaving blood glucose persistently high.
Why this answer works
- Presence of insulin does not guarantee an effective response.
- Name the target-cell problem.
- Link the impaired response to the regulated variable.
Is this true? "Type 2 diabetes always means the pancreas produces no insulin."
Insulin resistance and/or insufficient insulin are involved. Insulin may be present, and the balance of these problems varies between individuals.