Lesson 7 of 7 / Nutrition in humans
Type 2 diabetes and glucose control
Why can glucose remain high even when insulin is present?
I can explain type 2 diabetes, its risk factors and broad management approaches.
I can describe type 2 diabetes mechanisms.Syllabus
Syllabus K224 / K225, Topic 4(g). Describe type 2 diabetes mechanisms.
I can identify type 2 diabetes risk factors and management approaches.Syllabus
Syllabus K224 / K225, Topic 4(h). Identify type 2 diabetes risk factors and management approaches.
About 5 min
Make a guess. You are not marked.
A person with type 2 diabetes has high blood glucose. Does their pancreas make no insulin at all?
Show the answer
It usually makes some; cells respond poorly.
Insulin resistance means target cells take up less glucose. Insulin may be present, sometimes too little of it.
The key idea
Type 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
In type 2 diabetes, cells respond less well to insulin. This is called insulin resistance. At first the pancreas may make more insulin, but this may not be enough, and later it may make too little. So the blood glucose level stays high, not just for a short time after a meal.
Some things increase the risk of type 2 diabetes: not being active, having too much body fat and an unhealthy diet. Age and family history matter too. A risk factor makes the condition more likely, but it does not mean a person will definitely get it.
Treatment aims to keep the blood glucose level in a healthy range. This includes a balanced diet, regular exercise, checking blood glucose and, when needed, medicines from a doctor. Some people with type 2 diabetes need insulin.
In an exam answer, link the cause to the result: cells respond poorly to insulin, or too little insulin is made, so glucose is not taken up and stored properly, and the blood glucose level stays high. Eating one sugary food does not cause diabetes.
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.
Watch out for this
A student says: "Type 2 diabetes always means the pancreas produces no insulin." What is wrong with this?
Show the answer
Insulin resistance and/or insufficient insulin are involved. Insulin may be present, and the balance of these problems varies between individuals.
You may meet this in school papers
Not required by the 2027 syllabus, but school papers still ask it. Learn it after the main idea.
Type 1 diabetes
School papers sometimes compare type 1 and type 2 diabetes. In type 1 diabetes the body's immune system destroys the insulin-making cells of the pancreas, so little or no insulin is made; it usually starts in childhood and is treated with insulin injections. In type 2 diabetes, insulin is still made, but cells respond to it poorly. Your Combined Science syllabus only requires type 2 diabetes.
Check your understanding
Which statement about a sedentary lifestyle is accurate?
Show the answer
It raises the risk but does not decide who develops it.
Risk describes likelihood rather than certainty. Regular activity is one broad approach used in prevention and management.
Quick recall
Why can glucose remain high even when insulin is present?