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/m(2); 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 60minutes of sitting per day for standing or stepping on interleukin-6 (IL-6), C-reactive protein (CRP) and leptin. Reallocating 60minutes of sitting time per day for standing was associated with a -4% (95% CI -7%, -1%) reduction in IL-6 (p=0.048). Reallocating 60minutes 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%; p0.001)) and IL-6 (-16% (-28%, 10%; p=0.036). Theoretically replacing 60minutes of sitting per day with an equal amount of either standing or stepping yields beneficial associations upon markers of chronic-low grade inflammation.