Triglyceride-glucose index in the development of peripheral artery disease: findings from the Atherosclerosis Risk in Communities (ARIC) Study

Background: It remains unclear whether triglyceride-glucose (TyG) index, a surrogate marker of IR, was prospectively associated with incident PAD. Methods We included 12573 ARIC (Atherosclerosis Risk in Communities Study) participants free of PAD at baseline (1987–1989). The TyG index was determined using ln(fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2), and measured during 5 visits between 1987 and 2013. Incident PAD was defined as the first hospitalization with PAD diagnosis. We quantified the association of both baseline and trajectories of TyG index with incident PAD using Cox regression and logistic regression analysis, respectively. Results Over a median follow-up of 23 years, there were 1331 cases of incident PAD. After adjustment for traditional PAD risk factors, each 1-SD (0.58) increase in TyG index was associated with an 18.9% higher risk of incident PAD (hazard ratio, 1.189 [95% CI, 1.106–1.278]). Results were similar when individuals were categorized by TyG index quartiles (hazard ratio, 1.363 [95% CI, 1.125–1.652]; comparing extreme quartiles). Four distinct trajectories of TyG index were identified (low-increasing [43.0%], moderate-stable [22.3%], moderate-decreasing [27.6%], and high-decreasing [7.1%]). Trajectories of elevated TyG index levels had greater incident PAD after multivariable adjustment for potential cardiovascular risks. Compared with moderate-stable group (reference), high-decreasing group was associated with the highest risk of future incident PAD (odds ratio, 2.314 [95%CI, 1.687–3.175]). Conclusion Higher TyG index is independently associated with incident PAD. Long-term trajectories of TyG index help identify individuals at a higher risk of future PAD who deserve appropriate follow-up to detect asymptomatic disease.