Early
prediction and psycho-immunologic mediation of minor illness
in adulthood
Denise
Bellingham-Young & Elvidina Adamson-Macedo
University of Wolverhampton, Dept. of Psychology
Wulfruna Street, Wolverhampton WV1 1SB, UNITED KINGDOM
Keywords:
minor illness; Barker hypothesis; cognition; equilibrium model
Abstract
BACKGROUND:
The Barker Hypothesis suggests that an unfavourable uterine
environment can have the effect of programming the body for
disease later in life. Research indicates a bidirectional
relationship between thought and biochemical reactions, that
may be influenced by early programming. Reports suggest that
25% of variance in birthweight is a result of foetal environment
and that the health and cognitive deficits do not just affect
those with an officially low birthweight.
OBJECTIVE:
This study investigates the influence of birthweight on cognition
and minor illness in adults.
METHODS:
This is a retrospective, cross sectional design with an opportunity
sample of 75 adults. Participants whose birthweight ranged
from 2.5 kg to 4.88 kg, completed a symptom check list and
general self-efficacy scale, reporting on the previous month.
RESULTS:
Analysis of variance indicates that those with higher birthweight
have fewer minor illness symptom days and higher general self-efficacy.
Regression analysis indicates that birthweight is significantly
predictive of levels of minor illness and general self-efficacy.
CONCLUSION:
From the findings of this and previous studies, it is possible
to infer vertical coactions between foetal environment and
immuno competence. It is suggested that birthweight is an
early predictor of levels of a cognitive mediator and minor
illness. Data were applied to an equilibrium model to represent
the relationship in terms of Gottlieb's concept of horizontal
and vertical coactions.
Introduction
Psychoneuroimmunology
Psychoneuroimmunology (PNI) investigates interactions between
neural and neuroendocrine systems, psychological function and
immunity [1]. The immune system works in two ways. Humoural
immunity is most effective in dealing with pathogens that are
still outside the body's cells. Here antibodies are secreted
that bind to pathogens rendering them inactive. With cell-mediated
immunity, immune cells destroy the pathogen along with the host
cell it has invaded. This is most effective in dealing with
pathogens that have entered the body, such as virus and bacterial
infections [2].
The immune system can fail in one of two ways. First, it may
not be vigilant and allow pathogens to enter the body, or it
could be over vigilant, so that the immune system itself is
causing illness as in autoimmune disease. Secondly, it can become
unbalanced; when one branch of immune function is operating,
cytokines are produced that inhibits the alternative branch.
When operating normally, a person will fluctuate between the
functions over a 24 hour period. However, stress and other psychological
attributes such as cognition and emotion can influence the balance.
Stress for example can cause an increase in Thelper2 cells [3].
The presence of T-helper2 cells indicates an increase in humoural
immunity and associated decline in cell-mediated immunity [1].
Short term stressors have the effect of promoting antibody production
in saliva (SIgA) whilst long term stressors depress it [4].
Likewise, a small increase in stress in normal circumstances
results in increases in catecholamines and enhanced performance,
whereas in already stressful conditions, increased catecholamine
production results in deterioration of mental function and dysfunctional
behaviour. One of the functions of catecholamine secretion in
the "fight-or-flight" response to stress is to increase
heart rate, reduce blood flow to major organs and make blood
more prone to clotting thus reducing danger of heavy bleeding
in case of injury. At the same time however, this increases
the risk of arterial obstruction, hypertension and myocardial
infarction. In response to physical threat, catecholamines provide
an efficient mechanism for survival should the organism need
to fight or flee. However, in modern society, threat is more
likely to be of a social or mental nature rather than physical
[5].
Secretion of catecholamines is regulated by the influence of
the cortex on the hypothalamus in the central nervous system.
Research indicates that certain variables predict responses
to stimuli and have a buffering effect on cardiovascular, endocrine
and immune function. These variables include coping, optimism
[6] and self-efficacy [7], which have been experimentally linked
to a number of biochemical changes in stress situations. Interactions
influencing levels of health and minor illness are many and
complex, and it is possible that predictors are a result of
early life coactions.
The association between birthweight and major disease such as
coronary heart disease in later life has been confirmed by epidemiological
studies [8]. Size at birth is determined by interactions between
the intrauterine environment and the foetal genome, with 25%
of the variance arising from environment [9]. Birthweight has
also been associated with minor illness in adulthood [10], where
it was argued, that foetal programming may have resulted in
compromised immunocompetence.
Minor illnesses such as common cold, upper respiratory tract
infection (URT) and 'flu have frequently been investigated in
PNI research, as they are relatively common in the population,
are influenced by psychological factors [1] and are known to
be associated with changes in immune function such as increased
levels of T-helper2 cells [3]. The purpose of this report is
to extend a previous study [10] by investigating an additional
cognitive variable and applying data to a model representing
psycho-immunologic coactions. The assumptions are that according
to Barker's Hypothesis, in unfavourable conditions, blood may
be diverted from one part of the developing foetus, e.g. the
pancreas, in order to protect the growth of another part e.g.
the brain. This diversion or foetal compensation can leave the
body programmed for future illness and reduced cognitive function.
The
Baby In The Womb, In Utero
Coactions And Adult Minor Illness
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Psychological
Links To Early Environment
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General
Self-efficacy
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An
Equilibrium Model For Minor Illness
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