Association Between Change in Daily Ambulatory Activity and Cardiovascular Events in People With Impaired Glucose Tolerance (NAVIGATOR Trial): A Cohort Analysis
What is the association between baseline and change in objectively assessed ambulatory activity with the risk of a cardiovascular event in individuals at high cardiovascular risk with impaired glucose tolerance?
The investigators assessed prospective data from the NAVIGATOR trial involving 9,306 individuals with impaired glucose tolerance, who were recruited in 40 countries between January 2002 and January 2004. Participants also either had existing cardiovascular disease (if age ≥50 years) or at least one additional cardiovascular risk factor (if age ≥55 years). Participants were followed-up for cardiovascular events (defined as cardiovascular mortality, nonfatal stroke, or myocardial infarction) for 6 years on average, and had ambulatory activity assessed by pedometer at baseline and 12 months. Adjusted Cox proportional hazard models quantified the association of baseline and change in ambulatory activity (from baseline to 12 months) with the risk of a subsequent cardiovascular event, after adjustment for each other and potential confounding variables.
During 45,211 person-years of follow-up, 531 cardiovascular events occurred. Baseline ambulatory activity (hazard ratio [HR] per 2,000 steps per day, 0.90; 95% confidence interval, 0.84–0.96) and change in ambulatory activity (0.92; 95% confidence interval, 0.86–0.99) were inversely associated with the risk of a cardiovascular event. Results for change in ambulatory activity were unaffected when also adjusted for changes in body mass index and other potential confounding variables at 12 months.
The authors concluded that in individuals at high cardiovascular risk with impaired glucose tolerance, both baseline levels of daily ambulatory activity and change in ambulatory activity display a graded inverse association with the subsequent risk of a cardiovascular event.
This study reported that both baseline ambulatory activity and change in ambulatory activity over 12 months were associated independently with the risk of a cardiovascular event in the ensuing 5 years. Specifically, every 2,000 step per day increment in ambulatory activity at baseline (roughly equivalent to 20 minutes a day of moderately paced walking activity) was associated with a 10% lower risk of a cardiovascular event. These findings strengthen the evidence underpinning the importance of physical activity in the promotion of cardiovascular health, and appear to have important implications for public health recommendations.
Keywords: Glucose Intolerance, Myocardial Infarction, Body Mass Index, Cardiovascular Diseases, Risk Factors
< Back to Listings