OBJECTIVE: This cross-sectional study investigated insulin resistance (IR) variation across physical activity (PA) levels in U.S. adults. METHODS: MET-minutes were utilized to quantify PA using 2 methods: 4 categories were based on relative MET-minutes, and 5 were based on U.S. PA guidelines. IR was indexed using the homeostatic model assessment (HOMA). Effect modification was tested by dividing waist circumferences into sex-specific quartiles, and then evaluating the relationship between PA and HOMA-IR within each quartile separately. RESULTS: Relative PA was associated with HOMA-IR after controlling for demographic and demographic and lifestyle covariates (F = 11.5, P < 0.0001 and F = 6.0, P = 0.0012, respectively). Adjusting for demographic and demographic and lifestyle covariates also revealed relationships between guideline-based PA and HOMA-IR (F = 8.0, P < 0.0001 and F = 4.9, P = 0.0017, respectively). Controlling for waist circumference with the other covariates nullified the relationship between PA and HOMA-IR. Effect modification testing showed that when the sample was delimited to adults with extra-large waists (Quartile 4), relative (F = 5.6, P = 0.0019), and guideline-based PA (F = 3.7, P = 0.0098) and HOMA-IR were related. PA and HOMA-IR were not related within the other quartiles. CONCLUSION: High levels of PA may play a meaningful role in glucose and insulin metabolism in those with abdominal obesity, but not in adults with smaller waists.
College and Department
BYU ScholarsArchive Citation
Fowler, James R, "Physical Activity Level and Insulin Resistance in 6,500 NHANES Adults: The Role of Abdominal Obesity" (2019). Theses and Dissertations. 9127.
waist circumference, obesity, fitness, fat, diabetes