Body mass index influence the association between triglyceride-glucose index and atherosclerosis in community population: the cardiometabolic risk in Chinese (CRC) study

Background: Cardiovascular disease (CVD) is an universal problem in modern society. Atherosclerosis is the leading cause of CVD resulting in high rate of mortality in the population. The study aimed to examine the association of triglyceride-glucose (TyG) index, a novel marker of insulin resistance, with atherosclerosis in Chinese adults, and the effects of different body mass index (BMI) levels on this relationship.Methods: The study samples were from a community-based health examination survey in central China. A total of 4729 apparently healthy Chinese men and women were included. TyG index was calculated as ln[fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2]. Parameters of vascular damage, including carotid-femoral pulse wave velocity (cfPWV), carotid-radial pulse wave velocity (crPWV), carotid-dorsalis pedis pulse wave velocity (cdPWV) were measured.Results: After adjustment for conventional risk factors, TyG index was significantly associated with peripheral arterial stiffness (cdPWV>10.57cm/s or crPWV>11.12cm/s), however, TyG index was not associated with central arterial stiffness, measured by cfPWV. Moreover, we found significant interactions between TyG index and BMI in relation to crPWV and cdPWV. Risk for crPWV and cdPWV elevation was significantly decreased across increasing quartiles of TyG index under different BMI levels (P<0.001). There was a dose-response relationship of TyG index with crPWV and cdPWV in the normal-weight and overweight groups, with the most obvious in the normal-weight individuals. However, the dose-response relationship was not existed among the obesity group where the increase of TyG index did not significantly rise the risk of high crPWV and cdPWV.Conclusions: TyG index, a simple measure reflecting insulin resistance, might be useful to early identify individuals at a high risk of developing atherosclerosis. Increased BMI weakened the effect of TyG index on crPWV and cdPWV, indicating that the value of TyG index in assessing the risk of atherosclerosis in obese people maybe easily ignored, however, TyG index can better reflect the risk of atherosclerosis in normal-weight adults.