Biology Reference
In-Depth Information
Figure 11.1
Homo sapiens: Past and present!
insulin resistance, hypertension and dyslipidaemia)
[2,3]
. Chronic psychosocial stress,
with sustained activation of predominantly the defeat reaction, has also been shown
to be linked to diabetes type-2
[4]
and recent data from the British Whitehall study
confirm the link between chronic stress and the metabolic syndrome, showing a dose-
response relationship over 14 years period between work stress and the risk of devel-
oping the metabolic syndrome
[5]
. Furthermore, the large worldwide Interheart study
shows that presence of psychosocial stressors is associated with increased risk of acute
myocardial infarction
[6]
. In a recent paper describing the cardiovascular toll of stress,
the authors conclude that, despite relatively few well-controlled studies, evidence exist
for a strong and consistent association of acute and chronic psychosocial stress and
cardiovascular risk factors such as hypertension and insulin resistance
[7]
.
The decisive importance of the psychosocial environment is maybe best demon-
strated in two separate studies on genetically and culturally homogenous populations
clearly showing the impact of the social environment on rise in blood pressure with age
[8,9]
. Timio and co-workers showed in a 30 year follow-up study how the differences
in the social life situation almost entirely explained the blood pressure rise in a group
of women exposed to vivid Italian life-style compared to 150 nuns belonging to a
secluded order in the same area
[8]
. Hollenberg and co-workers came to a similar con-
clusion when studying the Kuna Indian tribe in Panama, comparing a group still living
the traditional life-style in their home islands compared to Kuna Indians who lived in a
suburb to or in the big-city environment of Panama City. Age-related increase in blood
pressure was not seen in Indians living traditional life-style, while the other groups
