Abstract

Bckground: Although cumulative evidence suggests that increased oxidative stress may lead to insulin resistance in vivo or in vitro, community-based studies are scarce.

Objective: This study examined the longitudinal relationships of oxidative stress biomarkers with development of insulin resistance and whether these relationships were independent of obesity in non-diabetic young adults.

Research design and methods: Biomarkers of oxidative stress (F₂-isoprostanes (F₂Isop) and oxidized LDL (oxLDL)), insulin resistance (the homeostasis model assessment of insulin resistance (HOMA-IR), and various fatness measures (Body Mass Index (BMI), waist circumference (WC), and estimated percent fat) were obtained in a population-based observational study (Coronary Artery Risk Development in Young Adults (CARDIA)) and its ancillary study (Young Adult Longitudinal Trends in Antioxidants (YALTA)) during 2000-2006.

Results: There were substantial increases in estimated mean HOMA-IR over time. OxLDL and F₂Isop showed little association with each other. Mean evolving HOMA-IR increased with increasing levels of oxidative stress markers (P<.001 for oxLDL and p=0.06 for F₂Isop), measured in 2000-01. After additional adjustment for adiposity, a positive association between oxLDL and HOMA-IR was strongly evident, whereas association between F₂Isop and HOMA-

Conclusion: We observed positive associations between each of two oxidative stress markers and insulin resistance. The association with oxidized LDL was independent of obesity, but that with F₂Isop was not.