Association between Estimated Glucose Disposal Rate and Impaired Cardiovascular Fitness in Non-diabetic Young Population: A Cross-sectional Study Based on NHANES Database

Background Recent studies have demonstrated that insulin resistance (IR) is associated with the development of cardiovascular diseases (CVD), and estimated glucose disposal rate (eGDR) has emerged as a reliable surrogate marker for IR. However, the majority of existing evidence is derived from studies involving elderly populations and diabetic patients, leaving early intervention strategies in non-diabetic young adults unclear. Therefore, the primary objective of this study is to investigate the relationship between eGDR and Impaired Cardiovascular Fitness(CVF) in young non-diabetic populations. Methods We screened data from the National Health and Nutrition Examination Survey (NHANES) study in a cross-sectional study of 3438 participants who completed the CVF examinations. Low and moderate levels of CVF, as determined by estimating maximal oxygen consumption (VO2 max) according to sex and age specific criteria, were defined as CVF impairment. Weighted logistic regression and subgroup analysis were used to explore the association between eGDR and impaired CVF. A smoothed curve fitting and threshold effect analysis were used to test for a linear relationship between eGDR and impaired CVF. Subgroup analyses with interaction tests were performed to assess the stability of the results. Furthermore, the mediation effect analysis was used to investigate whether certain variables mediate the association between the eGDR index and impaired CVF. Results Compared to the low eGDR group individuals with high eGDR were more likely to be female, younger, physically active and never smokers, and exhibited elevated HDL levels. In addition, BMI, WC, SBP, DBP, FPG, HbA 1 c, TG, and LDL showed lower levels in the high eGDR group. A significant negative relationship between eGDR index and impaired CVF appeared in weighted logistic regression analysis. Smoothed curve fitting further indicates that the strong negative association between eGDR and impaired CVF. Associations such as gender, age, and race remained stable in the subgroup analyses. In addition, BMI and LDL as mediators significantly affected the association of the eGDR index with the impaired CVF. Conclusions A lower level of eGDR was found to be associated with Impaired CVF among participants in our study. This finding highlights eGDR's potential as a valuable predictor and intervention target for CVF.