What is insulin resistance?

Long before diabetes has a name, the body's response to insulin quietly begins to change. Understanding that shift is the key to catching it early.

Insulin is the hormone that lets cells take up glucose from the blood for energy. Insulin resistance is what happens when those cells stop responding to it as well as they should, and the story of how the body copes explains a great deal about modern metabolic disease.

A compensation that eventually tires

At first, the body compensates: the pancreas simply makes more insulin to force glucose into resistant cells. For a while, blood sugar stays normal. But that extra demand cannot be sustained forever, over time the insulin-producing beta cells can exhaust, and blood sugar begins to rise. Insulin resistance is, in this sense, the primary driver of type 2 diabetes.¹

For years the numbers can look normal, while the effort behind them quietly climbs.

The wider web

Insulin resistance rarely travels alone. It sits at the centre of metabolic syndrome (a cluster of abdominal obesity, insulin resistance, high blood pressure, and abnormal blood lipids) accompanied by a low grade of chronic inflammation.² That clustering is part of why it matters so much for the heart as well as for blood sugar.

How common it is

It is strikingly widespread. The prevalence of type 2 diabetes in the United States rose from 2.5% of the population in 1990 to 10.5% in 2018, and roughly 88 million American adults, about one in three, are estimated to have prediabetes.¹ Because the early phase is silent, much of it goes unrecognised.