Objective: Data were retrieved from the Korean National Health and Nutrition Examination Surveys (2010-2019). Total of 15,764 participants aged 19~39 years with normal kidney function were enrolled. Participants were divided into tertile based on TyG index [ln(fasting triglyceride[mg/dL]x fasting glucose [mg/dL]/2)]. RHF was defined as eGFR with residuals >90thpercentile adjusted for sex, age, weight, and height. Methods: The mean age of the participants was 30.4± 6.1years, and 43.8% were male. The mean levels of TyG index were 7.70±0.25, 8.28±0.15 and 9.07±0.45 in tertile 1,2, and 3 respectively. The prevalence of RHF was significantly higher tertile (9.1%, 10.0%, and 10.9%, respectively, P for trend= 0.03). When the association between TyG index and risk for RHF was evaluated by multivariable logistic regression analysis, the higher tertiles showed increased risks for RHF compared to lowest tertile. (OR,1.24; 95% CI, 1.08-1.41, P=0.002 in tertile 2 and OR,1.64; 95%CI, 1.41-1.90, P<0.001 in tertile 3). This association was consistent when TyG index was treated as continuous variable(OR, 1.53; 95% CI, 1.39-1.38; P<0.001). TyG index increased risks for metabolic syndrome(MetS)(OR, 3.04;95% CI,1.86-4.97;P<0.001 in tertile 2 and OR,46.36; 95% CI,29.36-73.21;P<0.001 in tertile 3). Fasting glucose, low HDL and obesity of MetS criterion showed higher risk of RHF(OR1.19;95% CI 1.01-1.40;P=0.035, OR1.17;95% CI 1.03-1.32; P=0.014, OR1.74;95% CI 1.47-2.06;P<0.001, respectively). Results: Higher TyG index is associated with increased risk of RHF and MetS in Korean young adults with normal kidney function. Longitudinal studies are need to investigate whether TyG index and MetS associated RHF is a risk factor for kidney injury in young adults. Conclusions: Objective: Insulin resistance(IR) increases the risk for renal hyperfiltration(RHF), a mechanism for kidney injury in diabetes. However, the association between triglyceride-glucose(TyG)index, a novel marker for IR, and RHF is not well established. This study aimed to investigate the association between TyG index and RHF in Korean young adults. Methods: Data were retrieved from the Korean National Health and Nutrition Examination Surveys (2010-2019). Total of 15,764 participants aged 19~39 years with normal kidney function were enrolled. Participants were divided into tertile based on TyG index [ln(fasting triglyceride[mg/dL]x fasting glucose [mg/dL]/2)]. RHF was defined as eGFR with residuals >90thpercentile adjusted for sex, age, weight, and height. Results: The mean age of the participants was 30.4± 6.1years, and 43.8% were male. The mean levels of TyG index were 7.70±0.25, 8.28±0.15 and 9.07±0.45 in tertile 1,2, and 3 respectively. The prevalence of RHF was significantly higher tertile (9.1%, 10.0%, and 10.9%, respectively, P for trend= 0.03). When the association between TyG index and risk for RHF was evaluated by multivariable logistic regression analysis, the higher tertiles showed increased risks for RHF compared to lowest tertile. (OR,1.24; 95% CI, 1.08-1.41, P=0.002 in tertile 2 and OR,1.64; 95%CI, 1.41-1.90, P<0.001 in tertile 3). This association was consistent when TyG index was treated as continuous variable(OR, 1.53; 95% CI, 1.39-1.38; P<0.001). TyG index increased risks for metabolic syndrome(MetS)(OR, 3.04;95% CI,1.86-4.97;P<0.001 in tertile 2 and OR,46.36; 95% CI,29.36-73.21;P<0.001 in tertile 3). Fasting glucose, low HDL and obesity of MetS criterion showed higher risk of RHF(OR1.19;95% CI 1.01-1.40;P=0.035, OR1.17;95% CI 1.03-1.32; P=0.014, OR1.74;95% CI 1.47-2.06;P<0.001, respectively). Conclusions: Higher TyG index is associated with increased risk of RHF and MetS in Korean young adults with normal kidney function. Longitudinal studies are need to investigate whether TyG index and MetS associated RHF is a risk factor for kidney injury in young adults.