Association of smartphone-recorded steps over years and change in cardiovascular risk factors among working aged adults

Abstract

Abstract Backgrounds Evidence indicates a causal role of physical activity (PA), including steps, in decreasing cardiovascular disease (CVD) risk. However, few data exist on long-term steps and their relation to changes in CVD risk factors. Objectives To examine the associations of long-term smartphone-recorded steps and changes in CVD-related biomarkers in a large cohort of working aged adults. Methods The present analysis made use of data two national database and a commercial app database. Participants who underwent an annual health check-up between April 2015 and November 2020 and a second health check-up 24 to 35 months thereafter, and whose daily step data were available, were included. We evaluated the associations between smartphone-recorded daily steps over two years following the initial health check-up and two-year changes in the following CVD risk factors: weight, waist, blood pressure (BP), lipid and glucose metabolism biomarkers. Generalized additive models were used to investigate the non-linear relationships of steps and changes in CVD risks. Models were adjusted for baseline steps and other confounders. The present study design is summarized in Figure 1. Results A total of 15,708 participants with mean (SD) age of 44.1 (9.5) and 23.5% women were included. Differences in weight were almost linearly associated with two-year steps in men (estimate [SE] per 1000 steps/day: −0.33 [0.029] kg), and inversely related only above 5,000 steps/day in women (−0.18 [0.054] kg) (Figure 2). Similar trends were observed in waist. An inverse linear association with systolic BP was observed in men (−0.34 [0.097] mmHg) but not in women. Greater steps were associated with favorable change in HDL cholesterol and triglycerides (0.61 [0.068] and −3.4 [0.61] mg/dL in men; 0.64 [0.17] and −2.3 [0.67] mg/dL in women), while negative changes in LDL cholesterol was evident in men only (−0.59 [0.17] mg/dL). A significant negative association with HbA1c was observed only in women (−0.012 [0.0043] %). In the secondary analyses of the associations between one-year steps and one-year (i.e., 12 to 23 months) changes in CVD related biomarkers (N=26,884), the relationships were weaker and less robust compared with those in two-year analyses. Conclusions In a large cohort of Japanese adults, smartphone-recorded steps over years were associated with beneficial changes in CVD risk factors, with some differences between men and women in the associational patterns. The sex differences might highlight the undercount of steps among women who may be less likely to always carry their phone [1], or true sex differences in the effects of steps. The findings support the benefit of long-term PA for CVD health and suggest a useful role of smartphone-recorded steps for monitoring CVD risk over the long term. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): DeSC Healthcare Inc., Tokyo, Japan