Relationship between Clinical Factors Including Physical Activity and Job Category and Masked Effect Defined by Ambulatory Blood Pressure Monitoring

ABSTRACT

BACKGROUND: Masked hypertension is well known for its poor cardiovascular outcome. But clinical clues related to the masked hypertension and/or masked effect (ME) are rarely known. Physical activity and/or job stress are related to increased daytime blood pressure (BP). This study is to identify whether ME is caused by physical activity and/or job category. METHODS: Physical activity using Actical and masked effect by clinic BP and ambulatory BP monitoring were applied to 167 person for this study. RESULTS: Age of the subjects was 54.9 +/- 9.6 and 74 subjects were female (57.4%). Field worker was 81 (48.5%) and office worker was 86 (51.5%). Clinic BP was 125.8 +/- 14.3 mmHg / 79.8 +/- 10.9 mmHg in male and 119.0 +/- 14.0 mmHg / 74.2 +/- 8.9 mmHg in female (p = 0.03). Daily energy expenditure representing physical activity was 1,831.1 +/- 420.4 kcal. ME for systolic BP was 11.0 +/- 11.1 mmHg and ME for diastolic BP was 3.9 +/- 8.0 mmHg. In multiple linear regression adjusted by smoking and antihypertensive medication showed that clinic systolic BP was the only significant factor related to the ME (beta = -0.44755, p < 0.0001 in male, beta = -0.396, p < 0.0001 in female). Physical activity or job category was not related to ME. CONCLUSIONS: Neither physical activity nor job category is related to ME. This indicates that diagnosis of the masked hypertension is not affected by physical activity or job status.