Post-Diagnosis Decline in Moderate-to-Vigorous Physical Activity Is Associated with Higher Triglyceride and Fasting Glucose Levels in Newly Diagnosed Diabetes: A National Cohort Study

Background/Objectives: Evidence remains limited on how post-diagnosis changes in moderate-to-vigorous physical activity (MVPA) are associated with triglyceride and fasting glucose levels in newly diagnosed diabetes. We examined this association in a Korean national cohort. Methods: Using the National Health Insurance Service National Sample Cohort, we identified adults with newly diagnosed diabetes in 2009–2010 who completed health screenings in both 2010–2011 (period I) and 2012–2013 (period II). Period II MVPA frequency was examined within strata defined by period I MVPA category. Adjusted least-squares means for five metabolic indicators were estimated using multivariable linear regression. Results: Among 3719 participants, the clearest associations were observed among those performing MVPA five or more times per week during period I, in whom lower period II MVPA frequency was associated with higher triglyceride (P for trend = 0.036) and fasting glucose (P for trend = 0.015) levels. Increases in MVPA among initially inactive participants were not consistently associated with favorable metabolic profiles. Conclusions: A post-diagnosis decline in MVPA was associated with higher triglyceride and fasting glucose levels, particularly among initially active individuals. Preventing declines in MVPA after diabetes diagnosis may be clinically relevant.