OBJECTIVE: Exposure to particulate matter (PM) is a risk factor to diabetes, but the underlying mechanism is unclear. Adipokines play important roles in glucose metabolism. This study examined the associations between short-term exposure to ambient PM and adipokine levels and evaluated whether metabolic disorders could enhance susceptibility to PM-induced health effects. RESEARCH DESIGN AND METHODS: In a panel study (SCOPE, Study Comparing the Cardiometabolic and Respiratory Effects of Air Pollution Exposure on Healthy and Pre-diabetic Individuals) in Beijing, China, 60 pre-diabetic individuals and 60 healthy controls completed two to seven clinical visits. The associations between serum adiponectin, leptin, and resistin levels and the moving average (MA) mass concentration of PM2.5 and number concentrations of ultrafine particles (UFP) and accumulation-mode particles (AMP) during the 1-14 days prior to clinical visits, and the effects of metabolic disorders on any such associations, were evaluated using a linear mixed-effects model. RESULTS: Short-term exposure to ambient UFP and AMP was inversely associated with adipokine levels at 1-14 days prior to clinical visits. For example, each IQR increment in 1 day MA UFP exposure (6.0×103/cm3) was associated with -14.0% (95% CI -20.9%, -6.4%), -6.6% (95% CI -12.4%, -0.4%), and -8.5% (95% CI -14.5%, -2.2%) changes in adiponectin, leptin, and resistin levels, respectively. There was no significant association between adipokine levels and PM2.5 exposure. UFP and AMP exposure was associated with a greater decrease in adiponectin level and a weaker change in leptin level among participants with high insulin resistance levels. Glucose status did not modify PM-induced changes in adipokine levels. CONCLUSION: High level of insulin resistance could aggravate the adverse metabolic impact of exposure to UFP and AMP.