Association between device-measured stepping behaviours and cardiometabolic health markers in middle-aged women: The Australian Longitudinal Study on Women's Health.

The associations between different types and contexts of stepping behaviours and cardiometabolic (CM) health markers are unclear. This study aimed to examine the associations of daily total, walking, stair, incidental and purposeful steps with cardiometabolic risk. A total of 943 women (mean age±SD = 44.1±1.6 years) from the Australian Longitudinal Study of Women's Health (ALSWH) were included in this cross-sectional study. Daily total, walking, stair, incidental, and purposeful steps were measured using thigh-worn accelerometry. Outcomes comprised of CM markers of adiposity, blood pressure, resting heart rate, lipids, glycaemia and the composite CM score. We used generalised linear modelling and multiple linear regression to assess the associations. We observed that all stepping behaviours were beneficial to CM health, e.g., compared to the lowest quartile (Q1), the change of the composite CM score across low to high quartile of purposeful steps was -0.12 (Q2, 95% CI: -0.41, 0.17), -0.16 (Q3, -0.46, 0.14), and -0.36 (Q4, -0.66, -0.05). Stair steps showed linear associations with blood pressure and adiposity biomarkers, e.g., the change of quartile of waist circumference was -1.45cm (Q2, -4.35, 1.44), -3.56cm (Q3, -6.52, -0.60), -7.08cm (Q4, -10.31, -3.86). Peak 30-min walking intensity showed independent association with adiposity biomarkers ( P linear <0.001 and P=0.002 for waist circumference and BMI, respectively). Our study showed that all stepping forms were beneficial to CM health. Higher stair steps and peak 30-min walking cadence were associated with a steep decline of adiposity biomarkers. Purposeful steps showed more consistent associations with CM biomarkers than incidental steps.