Can step count be used to identify older adults with high sedentary time and low moderate‐to‐vigorous physical activity?

Abstract

IntroductionCombined high sedentary time (ST) and low moderate‐to‐vigorous physical activity (MVPA) has been associated with adverse cardiovascular events. However, accurately assessing ST and MVPA in older adults is challenging in clinical practice.PurposeTo investigate whether step count can identify older adults with unhealthier movement behavior (high ST/low MVPA) and poorer cardiometabolic profile.MethodsCross‐sectional study (n = 258; 66 ± 5 years). Step count, ST, and MVPA were assessed by hip accelerometry during 7 days. The cardiometabolic profile was assessed using a continuous metabolic syndrome score (cMetS), including blood pressure, HDL‐cholesterol, triglycerides, fasting glucose, and waist circumference. Receiving operating curve analysis was used to test the performance of step count in identifying older adults with unhealthier movement behavior (highest tertile of ST/lowest tertile of MVPA). Healthier movement behavior was defined as lowest tertile of ST/highest tertile of MVPA, with neutral representing the remaining combinations of ST/MVPA.ResultsA total of 40 participants (15.5%) were identified with unhealthier movement behavior (ST ≥ 11.4 h/day and MVPA ≤ 10 min/day). They spent ~73% and 0.4% of waking hours in ST and MVPA, respectively. Step count identified those with unhealthier movement behavior (area under the curve 0.892, 0.850–0.934; cutoff: ≤5263 steps/day; sensitivity/specificity: 83%/81%). This group showed a higher cMetS compared with neutral (β = .25, p = .028) and healthier movement behavior groups (β = .41, p = .008).ConclusionDaily step count appears to be a practical, simple metric for identifying community‐dwelling older adults with concomitant high ST and low MVPA, indicative of unhealthier movement behavior, who have a poorer cardiometabolic profile.