Date of Award
Doctor of Philosophy
Kinesiology and Sport Studies
Eugene C. Fitzhugh
James R. Churilla, Samantha F. Ehrlich, Scott E. Crouter, Lyndsey M. Hornbuckle
Purpose: To examine potential effect modification by race-ethnicity of the relationship between physical activity (PA) and diabetes-related mortality risk using a sample of U.S. adults from the Third National Health and Nutrition Examination Survey (NHANES III). Methods: The sample (n=10,717) included adults (≥20 years) who attended the Mobile Examination Center (MEC). An age-standardized PA score (PAS) was calculated from the self-reported frequency and intensity of 12 leisure-time aerobic activities. The PA scores were then grouped into three categories: inactive (PAS = 0), insufficiently active (PAS >0 - Results: There was no interaction between PA and race-ethnicity (p=0.83). Compared to inactive NHW, there was a significantly lower risk for diabetes-related mortality for insufficiently active (Hazard Ratio [HR] 0.51, 95% Confidence Interval [CI] 0.29-0.89) and active (HR 0.57, 95% CI 0.33-1.00) NHW adults. Statistical significance was not achieved for any level of activity for NHB and MA. A significant p-for-trend was revealed only for MA. Conclusions: The results of this study suggest that accumulation of any volume of PA is associated with a significantly lowered risk for diabetes-related mortality only in NHW. A significant dose-response relationship was only observed among MA. However, the interaction between race-ethnicity and PA did not attain statistical significance. Thus, the presence of effect modification could not be determined from the current study, but further investigation is warranted. Given longer follow-up time in the NHANES III cohort, the ability to estimate more precise risk reductions will become plausible.
Boyer, William Robert II, "Effect modification of the association between aerobic physical activity and diabetes-related mortality by race-ethnicity: a population-based prospective study using NHANES III and 1999-2006 NHANES. " PhD diss., University of Tennessee, 2017.