This study examined associations between sedentary time and skeletal muscle mass with ankle– brachial index (ABIR) -based vascular status (normal vs. abnormal) among young adult women. Health screening data from 49 women in their 20s were analyzed, with participants classified as normal (ABIR 1. 1–1. 3; n = 23) or abnormal (ABIR ≤ 1. 0; n = 26). Two cases with missing sedentary time were excluded (n = 47). Independent-samples t tests, logistic regression, and receiver operating characteristic (ROC; AUC) analyses were conducted, and a classification and regression tree (CART) model (70/30 split, seed = 42, maximum depth = 3) was used to explore potential cutoffs. Sedentary time tended to be longer in the abnormal group (8. 38 ± 3. 67 vs. 6. 31 ± 4. 05 hr/day; p =. 076), whereas skeletal muscle mass was significantly lower (23. 10 ± 3. 20 vs. 21. 45 ± 1. 84 kg; p =. 036). Logistic regression revealed trend-level significance for sedentary time alone (Model 1: OR = 1. 162, p =. 080), with both sedentary time (OR = 1. 228, p =. 033) and skeletal muscle mass (OR = 0. 697, p =. 021) significant in the combined model (Model 2). Model performance improved in Model 2 (Nagelkerke R² =. 273, AUC =. 727) compared to Model 1 (R ² =. 095, AUC =. 675). In CART, sedentary time of 4. 5 hr/day was selected as the first split, showing 93. 3% test accuracy (14/15) but requiring cautious interpretation. These findings suggest that longer sedentary time and lower skeletal muscle mass may jointly contribute to abnormal ABIR classification in young women.
Kim et al. (Thu,) studied this question.