Association of television viewing time with central hemodynamic parameters and the radial augmentation index in adults.

BACKGROUND: We conducted a study to explore the relationship between television viewing time and central hemodynamic parameters and the radial augmentation index (AIx) in adults.
METHODS: Random sampling was used to select 732 individuals who attended primary-care centers as subjects for the study. The self-reported time that these individuals spent in viewing television was elicited with a questionnaire and included the number of hours that they spent watching television while sitting or lying down. The subjects' physical activity was estimated through accelerometers attached to their waists. Central hemodynamic parameters and the peripheral augmentation index adjusted for a heart rate of 75 bpm (PAIx75) were measured with pulse-wave application software (A-Pulse CASP).
RESULTS: The subjects' systolic blood pressure (SBP) (central and peripheral), pulse pressure, and radial AIx showed significant differences between tertiles of television viewing time, with the lowest values in the first tertile (P < 0.01). After adjustment for age and sex, a multiple linear regression analysis showed an association of television viewing time with office SBP. Although the association of television viewing time with central SBP followed the same trend as for office BP, it did not reach statistical significance. After adjustment for age, sex, waist-to-height ratio, physical activity reflected by accelerometer data (counts/min), high-density lipoprotein cholesterol, smoking, antihypertensive and antidiabetic medication, and the use of lipid-lowering drugs, an increase in PAIx75 of 0.22 was estimated for each hour of increase in television viewing time (P < 0.01).
CONCLUSIONS: Television viewing time was directly correlated with PAIx75 in an adult population. This correlation was maintained even after adjustment for physical activity, age, sex, and other cardiovascular risk factors.