Analysis of sedentary behaviour levels and patterns in adults with Down syndrome.

BACKGROUND: Sedentary behaviour (SB) among adults with Down syndrome (DS) may differ based on personal or environmental factors. OBJECTIVE: Investigate differences in SB levels and patterns of adults with DS based on sex, age, and residence-type across weekdays and weekends. METHODS: Thirty-four adults with DS (15 men; 37 ± 12 years) underwent accelerometry-based measurements of sedentary time, bouts, and breaks for 7 days. We evaluated differences with 2 × 2 mixed-model (group-by-day) ANOVA. RESULTS: Younger (19-36 years) individuals had less sedentary time (p = .042), and shorter (p = .048) and fewer (p = .012) bouts than older (37-60 years) individuals. Group home residents had more bouts on weekends than adults living with parent/guardians (p = .015). CONCLUSIONS: Adults with DS spent half their waking hours in SB of short bouts. Age and residence may influence SB.

Physical activity and arterial stiffness: is body fat a mediator?

PURPOSE: Physical activity (PA) and body fat percentage (%BF) are independently associated with arterial stiffness, but it has not been explored if there is an associative pathway among these variables. This study examined whether %BF mediates the relationship between PA or sedentary behavior levels with arterial stiffness. METHODS: Fifty adults (1:1 men:women; age 28 ± 11 year) had carotid-femoral pulse wave velocity (CF-PWV) measured by applanation tonometry, %BF by bioelectrical impedance, and PA levels by accelerometry. Accelerometer data determined minutes per day spent in sedentary, light, moderate-to-vigorous physical activity (MVPA), and Total PA. RESULTS: Pearson correlation indicated statistically significant associations among age, %BF, CF-PWV, MVPA, and Total PA (r = 0.34-0.65, p < 0.05). Sedentary and light PA were not associated with CF-PWV. Mediation analysis indicated significant total effects of MVPA (ß = - 0.34, p = 0.044) and age (ß = 0.65, p < 0.001) on CF-PWV. %BF mediated the relationship between Total PA and CF-PWV due to indirect effect of Total PA on %BF (ß = - 0.34, p = 0.02) and %BF on CF-PWV (ß = 0.44, p = 0.002), and partially mediated the relationship between age and CF-PWV (ß = 0.54, p < 0.001). Total PA retained its significant effect on %BF (ß = - 0.28, p = 0.04) and the effect of %BF on CF-PWV remained significant (ß = 0.26, p = 0.03), despite age having a significant effect on both %BF (ß = 0.31, p = 0.023) and CF-PWV (ß = 0.54, p < 0.001). CONCLUSIONS: %BF mediated the relationship between Total PA and arterial stiffness, even after accounting for age. Engagement in more Total PA may help to reduce %BF, resulting in decreased arterial stiffness.

Health Outcomes of Physical Activity Interventions in Adults With Down Syndrome: A Systematic Review.

This systematic review examined whether physical activity interventions improve health outcomes in adults with Down syndrome (DS). We searched PubMed, APA PsycInfo, SPORTDiscus, APA PsycARTICLES, and Psychology and Behavioral Sciences Collection using keywords related to DS and physical activity. We included 35 studies published in English since January 1, 1990. Modes of exercise training programs included aerobic exercise, strength training, combined aerobic and strength training, aquatic, sport and gaming, and aerobic and strength exercise interventions combined with health education. The evidence base indicates that aerobic and strength exercise training improve physical fitness variables including maximal oxygen uptake, maximal heart rate, upper and lower body strength, body weight, and body fat percentage. Sport and gaming interventions improve functional mobility, work task performance, and sport skill performance. We concluded that adults with DS can accrue health benefits from properly designed physical activity and exercise interventions.

Vascular hemodynamics and blood pressure differences between young and older women.

BACKGROUND: Cardiovascular disease is one of the main causes of death in the United States, and hypertension is a primary risk factor. Therefore, the primary causes of hypertension need to be identified so they may be addressed for treatment. The purpose of this study was to compare blood pressure with hemodynamic values and identify factors that may explain blood pressure differences between a cohort of healthy normotensive younger and older women. METHODS: Participants were 49 young (age: 33.8 ± 5.9) and 103 old (age: 65.8 ± 4) who were non-hypertensive, had no previous history of heart disease or type 2 diabetes, body mass index less than 30 kg/m2, normal electrocardiography response at rest and during exercise, nonsmokers, and no use of medications known to affect cardiovascular or metabolic function. Body composition measured by dual-energy X-ray absorptiometry. Hemodynamic values measured by non-invasive pulse wave velocity through radial artery tonometry. Markers of inflammation measured through blood sample analysis. RESULTS: Significant differences exist between young and old groups in %fat (P < 0.001), systolic blood pressure (SBP) (P = 0.001), large artery elasticity (P = 0.005), small artery elasticity (P < 0.001), systemic vascular resistance (P = 0.004), total vascular impedance (P < 0.001), estimated cardiac output (P < 0.001), and tumor necrosis factor-⍺ (TNF-⍺) (P < 0.001). Using ANCOVA the difference in SBP between age groups was no longer significant after adjusting for small artery elasticity (P < 0.001) and TNF-⍺ (P = 0.041). CONCLUSIONS: These data demonstrate that blood pressure and vascular hemodynamic measures differ significantly between young and old women independent of body composition. Furthermore, these differences may be explained by the inflammation marker TNF-⍺ and/or small artery elasticity.