BRUSSELS: Increased risk of heart disease may be linked to stress hormone sensitivity: Study

BRUSSELS: People that are particularly
sensitive to stress hormones also exhibit markers that suggest they are at
greater risk of developing cardiovascular disease, according to research presented
at the 59th Annual European Society for Paediatric Endocrinology Meeting.
The study aimed to create a test that could differentiate between stress
hormone-sensitive and resistant people, to help clinicians better determine
therapeutic outcomes and minimise adverse effects in those requiring
glucocorticoid treatment.

Interestingly, the protein
profile associated with glucocorticoid sensitivity included increased risk
markers of stress-related disorders such as stroke and heart attack and may
point to new possibilities for diagnostics or therapy in these areas.

Glucocorticoids (GCs) are a group
of hormones produced naturally in the body, one of which is the stress hormone
cortisol, and they are essential for metabolism and healthy immune function.

They act as anti-inflammatories and are routinely used to treat allergies,
asthma and other conditions involving an overactive immune system. However,
people respond differently to GCs.

A test distinguishing between
sensitive and resistant people would be very useful in improving treatment
outcomes. Proteins in our body are responsible for recognising, transporting
and affecting the actions of hormones such as GCs, so it may be that the
protein profiles of sensitive and resistant people could indicate GC effectiveness.

Chronic stress has long been associated with an increased risk of developing
heart disease and stroke but the underlying physiological changes are not well
understood.

In this study, Dr Nicolas Nicolaides and colleagues in Athens, Greece, investigated
whether a set of proteins could be identified that would distinguish between GC
sensitive and resistant people.

101 healthy volunteers were given a low dose of the GC, dexamethasone, then
ranked from the most sensitive to most resistant, based on their blood cortisol
levels the following morning. Samples from the top and bottom 10 per cent were
then analysed using liquid chromatography-mass spectrometry to identify
differences in the protein profile between these groups.

The sensitive group had 110 upregulated and 66 downregulated proteins compared
with the resistant group. Of the upregulated proteins in the sensitive group,
several were associated with enhanced blood clotting, amyloid plaque formation
in Alzheimer’s disease and immune function.

Dr Nicolaides said the team’s
findings show, for the first time, how increased glucocorticoid sensitivity may
be associated with stress-related disorders, including myocardial and brain
infarctions, which could lead to new therapeutic interventions.

Although Dr Nicolaides,
cautioned, “This was a small study, so further, larger studies are needed
to confirm the differences observed between the glucocorticoid-sensitive and
resistant people.”

“We speculate that if the
most glucocorticoid sensitive people are exposed to excessive or prolonged
stress, the resultant increased blood cell activation could predispose them to
clot formation in the heart and brain, leading to heart attacks or strokes. We
could potentially identify those at more risk and in need of stress
management,” Dr Nicolaides commented.

This study was part of a larger project, involving genetic and metabolic
analyses in healthy subjects with differences in tissue sensitivity to
glucocorticoids. The team now plans to perform larger studies to confirm these
findings and develop a signature profile for identifying these patient groups,
which may also have increased susceptibility to stress-related disorders.