T2DM: Insulin Resistance Indicator Predicts Diabetes Risk

T2DM (Type 2 diabetes mellitus) is a chronic medical condition characterized by elevated blood sugar levels resulting from insufficient insulin production by the pancreas or the body’s reduced ability to use insulin effectively, known as insulin resistance. Elevated blood sugar levels can be toxic and lead to various malfunctions in our organs. Insulin resistance often occurs before a T2DM diagnosis and is associated with pre-diabetes conditions. While checking fasting blood sugar is one way to determine if you have diabetes, examining other parameters can provide early warnings to assess your risk of developing T2DM.

Medium Biomarkers of T2DM

For people with diabetes, just checking their regular blood sugar levels may not be enough to know if the condition is getting better. HbA1c is a better indicator of how well diabetes is under control.

Hemoglobin A1c (HbA1c) is a substance formed when sugar in our blood attaches to a protein called hemoglobin. It shows how well our blood sugar has been managed over the past 2-3 months.

The goal is to have an HbA1c level below 6.5% without needing medications other than metformin.

When HbA1c stays low for a year or more, it’s called remission, like when diabetes goes away or gets much better. Some people may achieve “partial remission” with an HbA1c below 6.5%, and others may reach “complete remission” with an HbA1c below 5.7% for over 12 months [1-5].

However, it’s essential to know that diabetes can still come back even after remission, so we don’t use the word “cure.” But controlling HbA1c is crucial for managing diabetes and reducing its complications.

Insulin Resistance and HOMA-IR

If blood glucose indicates short-term changes, HbA1c provides a medium-term perspective, while insulin resistance can be seen as a long-term indicator of diabetes. Insulin resistance refers to reduced sensitivity to insulin in the body and is often the first step towards developing type 2 diabetes. Therefore, assessing insulin resistance is essential for early detection of prediabetes.

The “gold standard” method for measuring insulin resistance is the “euglycemic-hyperinsulinemic clamp.” However, this test is invasive and not commonly used in clinical practice. Instead, a more convenient diagnostic tool is the “Homeostatic Model Assessment of Insulin Resistance” (HOMA-IR), which provides a reliable proxy for insulin resistance. To conduct HOMA-IR, both fasting glucose and fasting insulin levels need to be tested simultaneously.

HOMA-IR is a simple and indirect method to diagnose insulin resistance. The calculations are straightforward: higher insulin sensitivity is indicated by a lower need for insulin to maintain glucose levels, while higher insulin levels for the same fasting blood glucose level suggest a less optimal insulin resistance index. The calculation method is as follows:

During a general examination, only our fasting glucose is usually tested, not fasting insulin. However, relying solely on fasting glucose can only confirm if someone already has diabetes but does not offer any predictive value to assess the risk of developing diabetes in the near future.

In a recent study published in July 2023, researchers examined HOMA-IR in over 12,000 subjects and discovered that over 1/3 of obese children already show signs of insulin resistance. Those identified with insulin resistance through the HOMA-IR model are at an increased risk of developing dysglycemia within the next 10 years [6].

Summary

T2DM is characterized by elevated blood sugar levels due to insufficient insulin production or insulin resistance.

Hemoglobin A1c (HbA1c) provides a medium-term indicator of blood sugar control over 2-3 months.

Insulin resistance is a crucial early indicator of diabetes and can be assessed using the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR).

Monitoring HOMA-IR and assessing insulin resistance can aid in predicting the risk of developing T2DM.