Can Replacing Sitting Time with Standing Time Improve Adolescents' Cardiometabolic Health?

This study aimed to assess the effects of isotemporal replacement of sitting time (SIT) with standing (STA) on cardiometabolic biomarkers. In this cross-sectional study, male adolescents wore the GT3X+ activity monitor for 7 days to measure the SIT and STA. Moderate-to-vigorous physical activity (MVPA) was estimated by a youth-specific cut-off point. An isotemporal substitution approach was used to examine the effects of replacing different periods of SIT (15, 30, 60, and 120 min) with STA on cardiometabolic biomarkers [total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), non-HDL-c, low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), glucose, insulin, HOMA2-β, HOMA2-S, and HOMA2-IR]. Analysis of covariance (ANCOVA) with a post-hoc Bonferroni test was used to compare the adjusted means between the four subgroups that were clustered according to SIT and STA amount. Adolescents (n = 84; age, 16.7 ± 0.9 years) wore GT3X+ for 15.2 ± 2.3 h, for 6.7 ± 0.6 days. Isotemporal substitution of SIT with STA was associated with TC, non-HDL-c, LDL-c, and TG. ANCOVA results showed a statistically significant difference for TC, non-HDL-c, and LDL-c. These findings showed that for male adolescents, sitting less and standing more may be an effective alternative to reduce cardiometabolic biomarker levels related to lipid metabolism, regardless of MVPA.