Objective-To identify the baseline psychological variables before receiving a Diabetes Prevention Program (DPP) lifestyle intervention that predict physical activity levels (PALs) at baseline, 1 year, and end of study (2 to 3 years after randomization).Design and subjects-Of the final 293 DPP lifestyle participants randomized, 274 (94%) completed validated questionnaires at baseline assessing stage of change for PAL, exercise selfefficacy, perceived stress, depression, and anxiety.
Statistical analyses performed-Correlations and stepwise multiple regression analyses.Results-At baseline, this subset was similar to the entire DPP lifestyle cohort: mean age was 52.5 years, 65% were women, and mean PAL was 15.7 metabolic equivalent hours per week. Higher levels of baseline leisure PAL correlated with greater readiness to change PAL (r=0.44, P<0.0001), higher exercise self-efficacy (r=0.18, P=0.002), and lower levels of perceived stress (r=−0.16, P=0.009), depression (r=−0.18, P=0.003), and anxiety (r=−0.14, P=0.03), with similar correlations at 1 year and end of study. In multivariate models, being a man, lower levels of depression, and lower body mass index were independent correlates of higher baseline leisure PAL; being a man, greater baseline exercise self-efficacy, and activity level were independent correlates of greater leisure PAL levels at 1 year and end of study. Greater readiness to change PAL at baseline was also an independent correlate of greater PAL at end of study.Conclusions-In this representative sample of DPP lifestyle participants, being a man, lower body mass index, greater readiness for change in PAL, higher exercise self-efficacy, and lower perceived stress, depression, and anxiety scores correlated with higher levels of baseline PAL with similar patterns at 1 year and end of study. These findings may help determine which patients are most likely to increase PAL in lifestyle intervention programs.Lack of physical activity is a major risk factor for premature morbidity and mortality and contributes to the death of 200,000 Americans every year (1). Despite strong evidence for the benefits of regular physical activity (2,3), 24% of US adults engage in no recreational physical activity at all, and only 25% meet recommended physical activity levels (PALs) (4).One of the many major health benefits of regular physical activity is the prevention of type 2 diabetes (5-7), mediated by weight control and other mechanisms (6,8,9). Given that both inactivity and obesity seem to be strongly and independently associated with diabetes and diabetes-related cardiovascular comorbidities (10), it is particularly crucial to understand how to promote physical activity in persons at high risk for diabetes.Physical activity is a complex behavior that has been correlated with numerous demographic and psychological variables (11-13). However, much of the current literature focuses on the general population rather than on people at high risk for diabetes, like those with impaired glucose tolerance (IGT).The Diab...