On-call workday cardiovascular response. A study of medical residents

OBJECTIVE: To compare 24 h blood pressure changes in medical residents when on call with those of a normal workday. DESIGN: Ambulatory blood pressure was recorded in 30 normotensive residents (14 men and 16 women) aged 27+/-2 years, during on-call workdays (24 h in the hospital) and then compared with values obtained during a normal 8 h workday. Ambulatory blood pressure was recorded every 15 min during the day (0700-2200 h) and every 20 min during the night (2200-0700 h). RESULTS: The normal workday 24 h ambulatory mean blood pressure rose from 85.0 mmHg to the on-call mean blood pressure of 88.9 mmHg (P < 0.001). During the daytime, ambulatory systolic and diastolic blood pressures rose by 4.6 mmHg (P < 0.001) and 2.7 mmHg (P < 0.001), respectively. During the night-time period, systolic and diastolic blood pressures rose by 5.4 mmHg (P < 0.01) and 4.6 mmHg (P < 0.01), respectively. The nocturnal systolic and diastolic blood pressure elevation was not related to gender, body mass index, waist: hip ratio, physical exercise or smoking habits. CONCLUSION: The on-call workday causes an elevation in mean 24 h blood pressure and only minimal changes in the 24 h blood pressure pattern.