Associations between Incidental Physical Activity and Cardiometabolic Health in Sedentary Overweight and Obese Adults

Abstract

PURPOSE: This study explored associations between the volume and intensity of objectively measured habitual incidental physical activity (IPA) and cardiometabolic (CM) risk factors in sedentary adults. METHODS: Participants included 58 (female= 52; mean ± SD age = 45.9 ± 11.8 yrs.) overweight or obese (BMI = 32.5 ± 5.7 kg/m2) office workers. IPA was determined from activPAL-based energy expenditure estimates during 7-days of monitoring and defined as bouts of light intensity (LPA) and sporadic (< 10 min) moderate intensity (MPA) bouts of physical activity. CM health risk assessment consisted of body composition, anthropometrics, vascular hemodynamics, and blood biomarkers of CM health and inflammation. Statistical analyses (p<0.05) consisted of univariate and multivariate linear regressions between total IPA, LPA and MPA with CM health risk factors. Covariates entered into multivariate models were age, gender, accelerometer wear time, BMI, and total MPA duration accumulated in bouts ≥ 10 min. RESULTS: Average accelerometer wear time was 13.5 ± 1.6 hrs/day. Participants were sedentary for 8.6 ± 1.9 hrs/day and accumulated 4.8 ± 1.7 hrs. of IPA per day, of which 4.6 ± 1.7 hrs. were spent in LPA and 10.4 ± 6.6 min in MPA. Fifty-four participants did not meet the physical activity guidelines. Univariate models revealed significant inverse associations between daily IPA and insulin ((R2 = 0.16, p < 0.01) and HDL (R2 = 0.09, p < 0.05) and a positive association with trunk to leg % fat (R2 = 0.09, p < 0.05). Multivariate models strengthened the associations detected in univariate analyses: insulin (R2 = 0.27, p < 0.01) and HDL (R2 = 0.24, p < 0.01) and trunk to leg % fat (R2 = 0.28, p < 0.01). While duration of daily sporadic MPA was not associated with these variables, total daily LPA showed similar associations in both univariate and multivariate models. Conversely, sporadic MPA duration was inversely associated with IL-6 in both univariate (R2 0.09, p < 0.05) and multivariate models (R2 0.42, p < 0.001). CONCLUSIONS: IPA duration was a significant predictor of selected CM health risk factors. Increasing sporadic MPA may attenuate inflammatory response in sedentary overweight or obese adults. Findings suggest that interventions targeting increases in IPA may improve CM health profile in sedentary overweight and obese adults.