Risk of insulin resistance with statin therapy in individuals without dyslipidemia: A propensity-matched analysis in a registry population

Several studies suggest the higher vulnerability of individuals with lower low-density lipoprotein cholesterol (LDL-C) levels to diabetes mellitus. However, the discordance between high and low baseline LDL-C levels shown by statin-induced insulin resistance is not fully understood. This study aimed to explore the relationship between baseline LDL-C levels and the risk of statin-induced insulin resistance during statin therapy. In total, 2660 (451 with dyslipidemia and 2209 without dyslipidemia) consecutive patients were enrolled. Their baseline clinical data were adjusted using a propensity score matching analysis, using the logistic regression model. Insulin resistance index was based on the homeostatic model assessment-insulin resistance (HOMA-IR) and was monitored for a median of 2 years. Among the individuals who received statin therapy, those with and without dyslipidemia showed significantly decreased LDL-C levels (all P <.0001) and significantly increased fasting plasma insulin levels (Δ = +24.1%, P =.0230; Δ = +30.1%, P <.0001); however, their glycated haemoglobin A1c and fasting blood glucose levels did not change (all P >.05). Although HOMA-IR was positively associated with statin therapy in individuals with and without dyslipidemia, statistically significant difference during follow-ups was observed only in individuals without dyslipidemia (Δ = +15.6%, P =.1609; Δ = 24.0%; P =.0001). Insulin resistance was higher in statin users without baseline dyslipidemia than in those with dyslipidemia. Thus, statin therapy could increase the risk of statin-induced insulin resistance in individuals with normal baseline cholesterol levels.