A person's blood pressure normally drops during the night, but his or her socioeconomic status in childhood appears to influence how readily this occurs in adulthood, new Canadian research shows.
"These findings suggest that irrespective of adult achievement, childhood socioeconomic status may have lasting health implications," Dr Tavis S. Campbell of the University of Calgary in Alberta and colleagues write in the medical journal Psychosomatic Medicine.
Nocturnal drops, or "dips," in blood pressure of 10 percent to 15 percent are normal, and people who don't experience these night time blood pressure drops are at increased risk of heart disease and stroke. There is some evidence, Campbell and his team note, that blood pressure dipping may be related to socioeconomic status.
To investigate the relationship further, the researchers monitored blood pressure around the clock in 174 undergraduate students.
The lower a study participant's childhood socioeconomic status as rated by the highest level of education achieved by their parents, the investigators found, the less their blood pressure dropped at night.
No link to current socioeconomic status
On the other hand, study participants' current socioeconomic status, gauged by where they placed themselves on a nine-step "status ladder" relative to other Canadians, wasn't related to blood pressure dipping.
Socioeconomic status in childhood independently contributed to blood pressure dipping even after taking into account body mass index, smoking, and other relevant factors.
When looking at this study from a South African perspective, however, local expert and Health24's HeartDoc, Dr Anna Hall speculated that "Perhaps this is one of the mechanisms underlying the increasing incidence of heart disease in people who 'move up' and adopt a western lifestyle. What doesn't fit in though, is that those people who continue to live under the same adverse ses conditions, don't have the same indicence of heart disease. Why not, if the socioeconomic status is so significant? Or do these people succumb to other causes such as infectious disaeses, trauma or malnutrition, not living long enough to develop heart disease?
"Conversely, does continuing to live under these bad ses cause so much bp problems that they die early because of it, and simply are not recorded in our statistics? I'm sure there must be thousands of rural people whose true cause of death is never identified or reported, so how will we know?"
There are a number of ways by which early socioeconomic status could influence future heart disease risk, Campbell and colleagues say, including low birth weight, poor nutrition, and psychosocial factors such as stress.
They conclude: "Our findings highlight the importance of addressing childhood adversity and suggest one potential mechanism - BP dipping - of increased risk." - (Reuters Health)
SOURCE: Psychosomatic Medicine, April 2008.