In adults without diabetes, 10 weeks of atorvastatin 40 mg daily induces a greater increase in insulin resistance in individuals with lower baseline insulin resistance compared to those with higher baseline insulin resistance, indicating a ceiling effect in those already insulin resistant.

When statins block cholesterol production, cells in the muscle take up more cholesterol from the blood. This excess cholesterol builds up inside muscle cells and interferes with how insulin tells the cells to take in sugar. As a result, sugar stays in the blood longer, making the body more resistant to insulin. People who start with better insulin sensitivity have more room for this disruption to have a big effect, while those already resistant have less room to get worse.