If you believe there is a possibility that you have insulin resistance please get it tested. Insulin resistance can be present for years before other issue appear like Type 2 Diabetes or high blood pressure.  The insulin resistance test known as HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) provides information that is generally not available from a standard NHS blood test that only checks fasting glucose (blood sugar) or HbA1c (a measure of average blood sugar over the past 2-3 months).
Here is a breakdown of why HOMA-IR is more useful for people concerned about insulin resistance:

1. The HOMA-IR Calculation:
The HOMA-IR score is a calculated value derived from two simple fasting blood measurements:
Fasting Glucose (Blood Sugar)
Fasting Insulin
The formula is:
HOMA-IR= ConstantFasting Glucose×Fasting Insulin divided by a constant (The constant varies depending on the units used for glucose, e.g., 22.5 if glucose is in mmol/L)

2. Information HOMA-IR Provides (That Standard Tests Often Miss):

HOMA-IR Advantage	Explanation
Direct Estimation of Insulin Resistance	HOMA-IR is an established surrogate marker that estimates how resistant your body’s cells are to the effects of insulin. A standard NHS test for diabetes risk often focuses only on glucose or HbA1c .
Detection in the Early Stages	Insulin resistance often develops years before blood sugar levels become high enough to be classified as pre-diabetes or type 2 diabetes. The pancreas compensates for resistance by producing extra insulin to keep glucose normal. HOMA-IR captures this early stage: High Insulin + Normal Glucose = High HOMA-IR (Insulin Resistance).
Reveals Pancreatic Overwork	A high fasting insulin level alone, as part of the HOMA-IR calculation, indicates that your pancreas is having to work harder (hyperinsulinemia) to manage your blood sugar. This is a crucial early warning sign.
Earlier Intervention Opportunity	Since HOMA-IR can detect resistance while glucose is still normal, it gives individuals an earlier opportunity to make diet and lifestyle changes to reverse the resistance and potentially prevent the progression to pre-diabetes and type 2 diabetes.

How This is More Useful for People Suspecting Insulin Resistance:

If you suspect you have insulin resistance (perhaps due to symptoms like unexplained weight gain, fatigue, or conditions like PCOS), a standard NHS blood test checking only fasting glucose or HbA1c may come back as normal, falsely reassuring you that your metabolism is fine.
This is because the standard tests primarily measure the failure of the body to control blood sugar (i.e., when the pancreas can no longer keep up). HOMA-IR, by including fasting insulin, provides a measure of the effort the body is making to control blood sugar.
In summary: HOMA-IR is a more sensitive, early indicator of metabolic dysfunction compared to simply checking fasting blood glucose or HbA1c alone. It gives people a score that directly relates to their insulin sensitivity, empowering them to take preventative action long before a formal diagnosis of pre-diabetes or diabetes is made. 

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