A Cross-Sectional Examination of Patterns of Sedentary Behavior and Cardiometabolic Risk in Community-Dwelling Adults Aged 55 Years and Older.

Introduction: Sedentary behavior (SB) is highly prevalent among older adults, with more than 25% engaging in 6 hours or more of SB daily. SB has been associated with several cardiometabolic biomarkers in younger adults; however, there is a paucity of research in older populations. This study examined associations between patterns of SB and cardiometabolic biomarkers in community-dwelling adults aged 55 years and older.

Methods: Data were drawn from a convenience sample of 54 community-dwelling individuals (12 males, 42 females; mean age = 72.6 ± 6.8 years, range = 56-89 years). Cardiometabolic biomarkers assessed included systolic (SBP) and diastolic blood pressure (DBP), body mass index, waist circumference, and fasting blood glucose and cholesterol parameters. SB was assessed via accelerometry over a 7-day period, and measures included daily time in SB, number and length of sedentary bouts, the number and length of breaks between sedentary bouts, moderate-to-vigorous physical activity (MVPA), and light physical activity (LPA). Associations between the SB measures and each cardiometabolic risk factor were examined using separate stepwise multiple regression models, controlling for sex, MVPA, and accelerometer wear time. Isotemporal substitution models were used to examine the change in cardiometabolic outcomes when SB is replaced by an equal duration of either LPA or MVPA.

Results: Adjusted regression analyses showed that daily sedentary time was positively associated with DBP (β = 0.052, ∆R ² = 0.112, p = 0.022) and inversely associated with HDL cholesterol (β = -0.111, ∆R ² = 0.121, p = 0.039). Sedentary bout length was also associated with DBP and HDL cholesterol (β = 0.575, ∆R ² = 0.152, p = 0.007; β = -1.529, ∆R ² = 0.196, p = 0.007, respectively). Replacement of 10 minutes of SB a day with LPA was associated with improved DBP and HDL cholesterol (p ≤ 0.05). No other significant associations (p ≤ 0.05) were found.

Conclusion: Sitting for prolonged periods of time without interruption is unfavorably associated with DBP and HDL cholesterol. Prospective studies should identify causal relationships and observe specific changes in cardiometabolic profiles in older populations.