Purpose: The associations between work time, leisure-time, and non-workday physical activity (PA) and sedentary behavior (SED) and 24 h ambulatory blood pressure (BP) are not well known. Therefore, the aim of this study was to evaluate the associations between domain-specific activity behavior and 24 h blood pressure.

Methods: A hundred and fifty-six aging workers (mean age 62.4 [SD 1.0] years, BMI 26.2 [4.5] kg/m2, 84 % women, 75 % non-manual occupation) from the Finnish Retirement and Aging study (FIREA) were included. Standing, light and moderate-to-vigorous PA (LPA and MVPA, respectively), and SED were measured using thigh-worn accelerometers and work time, leisure-time, and non-workdays were distinguished using a diary. Ambulatory 24 h BP was analyzed as mean daytime and nighttime systolic and diastolic BP, and the nocturnal BP dipping percentage was calculated. Associations were examined with linear regression analysis adjusting for age, sex, occupation, work time mode, job strain, BMI, BP medication, and accelerometer wear time.

Results: Higher work time SED associated with lower nighttime diastolic BP (B = -0.92, 95% CI -1.83, -0.01). In addition, higher work time standing associated with higher daytime diastolic BP (B = 1.34, 95% CI 0.03, 2.65) and higher work time LPA with less diastolic BP dipping (B = -3.57, 95% CI -6.80, -0.34). MVPA in any domain was not associated with ambulatory BP.

Conclusions: Higher work time SED associated with a more favorable diastolic BP, and higher work time PA associated with more adverse diastolic BP among aging workers. In conclusion, work time, rather than leisure time or non-workday, activity behavior seems to associate with 24 h ambulatory BP.