AimsFew population-based studies have investigated the association between insulin resistance and atherosclerotic burden in intra- and extra-cranial arteries. The purpose of this study is to explore the relationship between insulin resistance and intra- and extra-cranial atherosclerotic burden in community-based nondiabetic participants. MethodsThis is a cross-sectional analysis from a population-based prospective cohort-PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE) study in China. The homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity indices (ISI0–120) were stratified by the quartiles, respectively. The atherosclerotic presence of plaques and burden was evaluated by high-resolution MRI. Binary or ordinal logistic regression was performed to assess the association between HOMA-IR or ISI0–120 and the presence and burden of atherosclerosis. ResultsAmong the 2754 participants, the mean age was 60.9 ± 6.6 years, and 1296 (47.1%) were males. Compared with the lowest quartile of HOMR-IR, the highest quartile of HOMA-IR (indicating a higher level of insulin resistance) was associated with an increased presence of plaques (OR:1.54, 95% CI:1.14–2.08), and atherosclerotic burden (OR:1.53, 95%CI:1.14–2.07) in intracranial arteries. Meanwhile, we observed a similar relationship between HOMA-IR and the presence or burden in extracranial atherosclerosis. The first (indicating a higher level of insulin resistance) quartiles of ISI0–120 were associated with the intracranial plaques (Q1, OR:1.56, 95%CI:1.16–2.11) and atherosclerotic burden (Q1, OR:1.57, 95%CI:1.17–2.12), but not extracranial plaques or atherosclerotic burden, compared with the fourth quartile of ISI0–120. ConclusionsInsulin resistance was associated with an increased intra-and extra-cranial atherosclerotic burden in the nondiabetic elderly Chinese population.