Hostility modifies the association between TV viewing and cardiometabolic risk

Associations of nonoccupational sedentary behaviors with cardiometabolic outcomes: coronary artery risk development in young adults (CARDIA)

BACKGROUND

The association between sedentary behavior (SB) and cardiometabolic risk may differ by SB domain and context. Nonoccupational SB is particularly important because it is discretionary and more amenable to change. This study estimated associations of nonoccupational SB contexts with hypertension (HTN) and diabetes mellitus (DM).

METHODS

A total of 3370 middle-aged adults (50.1 ± 3.6 years; 56% F) from the Coronary Artery Risk Development in Young Adults (CARDIA) study were included. Cross-sectional and 5-year prospective associations between self-report total SB and 6 context-specific SBs (television-TV, computer, transportation, phone, music, and paperwork) with HTN and DM were tested using logistic regression. Fully adjusted models controlled for sociodemographic variables, body mass index, and self-report moderate-vigorous intensity physical activity.

RESULTS

Prevalences of HTN and DM at baseline were 48% (1618 cases) and 10% (320 cases), respectively. Each hour per day of total-SB was cross-sectionally associated with HTN (OR: 1.03, 95% CI, 1.01-1.05) but not DM, with nonsignificant prospective associations for HTN and DM. Of the context-specific SBs, only TV-SB was significantly associated with HTN or DM. Each hour of TV-SB was cross-sectionally associated with HTN (OR: 1.09, 95% CI, 1.03-1.15) and DM (OR: 1.18, 95% CI, 1.09-1.29), and prospectively with HTN (OR: 1.14, 95% CI, 1.04-1.26) but not DM.

CONCLUSION

When comparing total-SB and the 6 context-specific SBs, TV-SB was most robustly associated with HTN. The findings were less clear for DM. Behavior change strategies that target TV-SB reduction may be effective at reducing HTN risk in middle-aged adults.

Sedentary Behaviors and Cardiometabolic Risk: An Isotemporal Substitution Analysis

Evidence suggests that time spent engaging in sedentary behaviors is associated with a greater risk of adverse cardiometabolic outcomes. We investigated the cross-sectional associations of 6 unique sedentary tasks (watching television, using the computer, completing paperwork, reading, talking on the telephone, and sitting in a car) with cardiometabolic risk factors, and also examined the effect of replacing one type of sedentary behavior with another on the level of cardiometabolic risk. Participants consisted of 3,211 individuals from the Coronary Artery Risk Development in Young Adults Study who visited the clinic between 2010 and 2011. Linear regression models examined the independent and joint associations of sedentary tasks with a composite cardiometabolic risk score, as well as with individual cardiometabolic risk factors (waist circumference, blood pressure, fasting glucose, insulin, triglycerides, and high density lipoprotein cholesterol) after adjusting for physical activity and other covariates. Replacing 2 hours of television viewing with 2 hours spent performing any other sedentary activity was associated with a lower cardiometabolic risk score of 0.06-0.09 standard deviations (all 95% confidence intervals: -0.13, -0.02). No other replacements of one type of sedentary task for another were significant. Study findings indicate that television viewing has a more adverse association with cardiometabolic risk factors than other sedentary behaviors.