RESUMEN
OBJECTIVE: Effects of environmental conditions on blood pressure (BP) and heart rate (HR) variations as putative factors underlying the onset of vascular events. METHODS: BP and HR were monitored around the clock for 7 days on 54 residents from Urausu, Hokkaido, Japan. Daytime, night-time, and 24-h means served to identify dippers and non-dippers. Questionnaire-assessed depression and subjective quality of life were related to BP and HR by analyses of variance and linear regression. Statistical significance was at 5%. RESULTS: A circaseptan (about 7-day) component characterizes the 24-h mean and standard deviation (SD) of HR, and the daytime and day-night ratio of systolic BP. The SD of HR is higher on weekends and lower on Mondays and Thursdays. When awake, systolic BP is lowest on Sundays and the day-night ratio is optimal on weekends (Saturdays: 15.7 +/- 9.4%; Sundays: 14.0 +/- 13.2%). Depression was detected in 15 subjects, who had higher mean systolic and diastolic BP values (systolic BP: P = 0.028 Fridays, P = 0.021 Tuesdays; diastolic BP: P = 0.022 Mondays, P = 0.006 daytime Mondays) and a lower day-night ratio of diastolic BP (P = 0.012 Tuesdays, P = 0.005 Wednesdays, and P = 0.038 Thursdays). A depressive mood correlated positively with 24-h averages of systolic (P = 0.037) and diastolic (P = 0.030) BP. CONCLUSIONS: Depression (and subjective quality of life) can affect BP and HR variability. The results indicate the role that psychological factors may play in the pathogenesis of cardiovascular disease. Therapeutic implications are suggested for primary and secondary prevention.