Protocol for a study on Sitting with Interruption and Whole-Body Cardiovascular Health (SWITCH) in middle-aged adults.

BACKGROUND: Sedentary behavior (SB) is a biologically distinct yet understudied cardiovascular disease risk (CVD) factor. However, specific public health policy regarding the optimal strategy for SB interruption is unavailable. This paper outlines the protocol for part I of the Sitting with Interruption and Whole-Body Cardiovascular Health (SWITCH) study, including the rationale, objectives, methodology, and next steps. We additionally detail practical considerations that went into the development of the NIH R01 grant supporting this research. METHODS: Healthy men and women (n = 56, aged 36-55) who are inactive (<90 min/wk. of moderate-to-vigorous intensity physical activities for past 3 months) and sedentary (sitting for >8 h/day), will be recruited for this randomized crossover trial. Specifically, participants will complete the following 4-h conditions: (i) SB with once/h 5 min walk break; (ii) SB with once/h 15 min stand break; (iii) SB with twice/h breaks (alternating 5 min walk and 15 min stand); and (iv) SB with no breaks (i.e., control). Focus group discussions will refine our socioecological SB reduction model. RESULTS: The primary outcome will be change in aortic arterial stiffness (i.e., pulse wave velocity; PWV, m/s) for each substitution strategy relative to the control (SB with no breaks) condition. CONCLUSIONS: The outcomes from this study will facilitate the design of a subsequent randomized controlled trial to test a mechanism-informed, feasible SB-reduction intervention and support the development of SB policy.

Predictors of uncontrolled hypertension in the Stroke Belt.

Inadequate control of high systolic blood pressure in older adults has been largely attributable to poor control of overall hypertension (HTN). The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guidelines emphasize the importance of controlling isolated systolic HTN in older adults. The study examined demographics, self-reported health information, and clinical measures as predictors of uncontrolled HTN among individuals taking antihypertensive medications. The Community Initiative to Eliminate Stroke, a stroke risk factor screening and prevention project, collected data in two North Carolina counties. Statistical modeling of predictors included odds ratios (ORs) and logistic regression analyses. Of the 2663 participants, 43.5% and 22.8% had uncontrolled systolic and diastolic HTN, respectively. African Americans were more likely to have uncontrolled systolic (60%) or diastolic HTN (70.9%) compared with whites (40% and 29.1%, respectively). Participants 55 years and older were more likely to have uncontrolled systolic HTN compared with younger individuals. Regression analyses showed that race (OR, 1.239; P=.00), age (OR, 1.683; P=.00), and nonadherence with medications (OR, 2.593; P=.00) were significant predictors of uncontrolled systolic HTN. Future interventions should focus on improving management of isolated systolic HTN in older adults and African Americans to increase overall control of HTN.

Predictors of congruency between self-reported hypertension status and measured blood pressure in the stroke belt.

BACKGROUND: Few studies have comprehensively investigated the validity of self-reported hypertension (HTN) and assessed predictors of HTN status in the stroke belt. This study evaluates validity self-reporting as a tool to screen large study populations and determine predictors of congruency between self-reported HTN and clinical measures. METHODS: Community Initiative to Eliminate Stroke project (n = 16,598) was conducted in two counties of North Carolina in 2004 to 2007, which included collection of self-reported data and clinical data of stroke-related risk factors. Congruency between self-reported HTN status and clinical measures was based on epidemiological parameters of sensitivity, specificity, and predictive values. McNemar's test and Kappa agreement levels assessed differences in congruency, while odds ratios and logistic regression determined significant predictors of congruency. RESULTS: Sensitivity of self-reported HTN was low (33.3%), but specificity was high (89.5%). Prevalence of self-reported HTN was 16.15%. Kappa agreement between self-report and clinical measures for blood pressure was fair (k = 0.25). Females, whites, and young adults were most likely to be positively congruent, whereas individuals in high risk categories for total blood cholesterol, low density lipoproteins, triglycerides, and diabetes were least likely to accurately capture their HTN status. CONCLUSION: Self-report HTN information should be used with caution as an epidemiological investigation tool.