Supplementary information files for "Associations of objectively measured physical activity, sedentary time and cardiorespiratory fitness with adipose tissue insulin resistance and ectopic fat"

<p dir="ltr">Supplementary information files for article "Associations of objectively measured physical activity, sedentary time and cardiorespiratory fitness with adipose tissue insulin resistance and ectopic fat"</p><p dir="ltr"><b>Background/objectives</b> Inadequate movement, excess adiposity, and insulin resistance augment cardiometabolic risk. This study examined the associations of objectively measured moderate-to-vigorous intensity physical activity (MVPA), sedentary time and cardiorespiratory fitness (CRF), with adipose tissue insulin resistance and ectopic fat.</p><p dir="ltr"> <b>Methods </b>Data were combined from two previous experimental studies with community volunteers (n=141, male=60%, median (interquartile range) age=37 (19) years, body mass index (BMI)=26.1 (6.3) kg·m-2). Adipose tissue insulin resistance was assessed using the adipose tissue insulin resistance index (Adipo-IR); whilst magnetic resonance imaging (MRI) was used to measure liver, visceral (VAT) and subcutaneous abdominal adipose tissue (ScAT). Sedentary time and MVPA were measured via an ActiGraph GT3X+ accelerometer. Generalized linear models examined the association of CRF, MVPA, and sedentary time with Adipo-IR and fat depots. Interaction terms explored the moderating influence of age, sex, BMI and CRF. </p><p dir="ltr"><b>Results</b> After controlling for BMI and cardiometabolic variables, sedentary time was positively associated with Adipo-IR (β=0.68 AU [95%CI=0.27 to 1.10], P<0.001). The association between sedentary time and Adipo-IR was moderated by age, CRF and BMI; such that it was stronger in individuals who were older, had lower CRF and had a higher BMI. Sedentary time was also positively associated with VAT (β=0.05 L [95%CI=0.01 to 0.08], P=0.005) with the relationship being stronger in females than males. CRF was inversely associated with VAT (β=-0.02 L [95%CI=-0.04 to -0.01], P=0.003) and ScAT (β=-0.10 L [95%CI=-0.13 to -0.06], P<0.001); with sex and BMI moderating the strength of associations with VAT and ScAT, respectively. </p><p dir="ltr"><b>Conclusions</b> Sedentary time is positively associated with adipose tissue insulin resistance which regulates lipogenesis and lipolysis. CRF is independently related to central fat storage which is a key risk factor for cardiometabolic disease.</p><p dir="ltr">© The Authors, CC BY 4.0</p>