Introduction:
Step counts are an easy way for individuals to quantify their physical activity; there is limited data relating accelerometer-derived step counts with the onset of cardiovascular risk factors. We hypothesized that steps/day are inversely associated with type 2 diabetes, stage 2 hypertension, and obesity 10 years later.
Methods:
Data are from 1,923 CARDIA study participants with valid (≥4 days with ≥10 hours/day) accelerometer wear (ActiGraph 7164) in 2005-2006 with at least one follow-up visit 5- or 10- years later. Multivariable Cox models calculated hazard ratios (HR) and 95% confidence intervals (CI) for incidence of type 2 diabetes, stage 2 hypertension, and obesity.
Results:
The analytic sample (45.3±3.6 years; 58% women, 41% black) had a mean follow-up of 9.7±1.3 years. After adjusting for demographics and lifestyle characteristics, every 1000 higher steps/day was associated with a 10% lower risk of diabetes and 5% lower risk of hypertension. When adding comorbidities to the model, the HRs were slightly attenuated, and remained significant for diabetes [0.93 (95% CI, 0.87-0.99)]. Compared to the lowest step quartile, the highest quartile was at a 43% lower risk of diabetes and a 31% lower risk of hypertension. When testing for interactions by race or sex, the only significant interaction was for sex with obesity as the outcome. Steps were only associated with obesity in women, where every 1000 higher steps/day were associated with a 13% lower risk, and the highest quartile was 61% less likely to develop obesity compared to the lowest quartile.
Conclusions:
Among middle age adults, accumulating a higher volume of steps/day was associated with a lower risk of type 2 diabetes and stage 2 hypertension. In women, higher steps/day was associated with lower risk of obesity. Encouraging the accumulation of steps/day may be an effective public health strategy to lower the burden of cardiovascular risk factors.
Clinical profiles and quality of care of subjects with type 2 diabetes according to their cardiovascular risk: an observational, retrospective study
