Reallocating sitting time to standing or stepping through isotemporal analysis: associations with markers of chronic low-grade inflammation

Although high levels of sitting time are adversely related to health, it is unclear whether moving from sitting to standing provides a sufficient stimulus to elicit benefits upon markers of chronic low-grade inflammation in a population at high risk of type 2 diabetes (T2DM). Three hundred and seventy two participants (age = 66.8 ± 7.5years; body mass index (BMI) = 31.7 ± 5.5kg/m²; Male = 61%) were included. Sitting, standing and stepping was determined using the activPAL3^TM device. Linear regression modelling employing an isotemporal substitution approach was used to quantify the association of theoretically substituting 60 minutes of sitting per day for standing or stepping on interleukin-6 (IL-6), C-reactive protein (CRP) and leptin. Reallocating 60 minutes of sitting time per day for standing was associated with a ?4% (95% CI ?7%, ?1%) reduction in IL-6 (p = 0.048). Reallocating 60 minutes of sitting time for light stepping was also associated with lower IL-6 levels (?28% (?46%, ?4%; p = 0.025)). Substituting sitting for moderate-to-vigorous (MVPA) stepping was associated with lower CRP (?41% (?75%, ?8%; p = 0.032)), leptin (?24% (?34%, ?12%; p ≤ 0.001)) and IL-6 (?16% (?28%, 10%; p = 0.036). Theoretically replacing 60 minutes of sitting per day with an equal amount of either standing or stepping yields beneficial associations upon markers of chronic-low grade inflammation.