Blood pressure response to the daily stressors of urban environments: Methodology, basic concepts, and significance

Blood pressure is studied in epidemiological and anthropological research as if each person has a single unique value. However, blood pressure is a fluctuating physiological function with significant intraday variability. This paper discusses and describes the methodology and basic concepts of ambulatory blood pressure monitoring as it has been employed to assess blood pressure variability in the continuously changing microenvironments of Western urban settings. Across urban microenvironments, blood pressures, on average, are highest while people are at work and are lowest during sleep. Blood pressure is further affected by emotional state and activity (which differ between men and women), the season of the year (winter and summer), and occupation. Differences in daily blood pressure variation also occur between ethnic groups (black versus white). The review also considers whether salt intake and other behavioral factors affect daily blood pressure variation. Finally, the review explores the use of ambulatory pressure monitoring for genetic studies. Before we can conclude that a varying physiological function like blood pressure helps individuals to adapt to changing daily environments, blood pressure must be studied under all daily conditions. If future human populations must adapt to the urban environment, then ambulatory blood pressure technology may be one tool that physical anthropologists can use to elucidate the direction of human evolution.