How stress can drive insulin resistance, metabolic syndrome, & diabetes
We know psychosocial stress can set one at risk for all
sorts of disease. To add one more to the list - risk for developing type 2
diabetes has its correlations with the body’s stress response as well,
specifically, a chronic stress response.
Individuals living with type-2 diabetes are often warned
that stress can acerbate their conditions, putting their health at risk. In
humans’ hunting and foraging days, our stress response helped us get out of
trouble quick. And by trouble I mean, that hog we just tried to spear and
missed is looking pretty angry, charging at our gut with six-inch tusks. Our
stress response would be triggered, seconds later releasing more glucose into
our bloodstream, to provide our bodies an energy boost to scramble up a tree to
safety. We rarely suffer these same problems anymore, but our bodies wouldn’t
know the difference.
 |
| Photo courtesy of Sidereal {http://www.flickr.com/photos/sidereal/} |
In a diabetic individual (type-2) with insulin resistance,
glucose cannot adequately be taken up into storage and accumulates in the
bloodstream. You may have already seen the connections; the glucose that gets
unpacked and moved into the blood under stressful circumstance can unnecessarily
add dangerous amounts to the diabetic’s blood supply. These elevated levels can
lead to all sorts of another serious problems then.
But how can stress lead to diabetic, pre-diabetic or
dysglycemic conditions?
There is a complex path on the way to
diabetes that stress can lead a
primary role in, holding your hand the whole way. It starts with a sugar
craving. If you’re anything like me, you – well, first, have quite the sweet
tooth to start out with – but also, grab for anything sugary when feeling
stressed out.
Many people cope with their stress by overeating or pursuing
incentives. So, if your vice has always been sugar, you’re going to crave it
when you’re stressed. Our brains release dopamine - that works on the
pleasure-pathways (mentioned in my depression post) - at the beginning of a
stressful event if there is a high probability of reward at the end of it
(Sapolsky, 2004). Additionally, corticotropin-releasing factor (CRF) –
experienced by us when we’re under stress – exaggerates cravings for a reward
(Serwach, 2006). Humans have had a long and loving relationship with sugar;
unsurprisingly, it is definitely reward enough for most of us.
Additionally, our bodies utilize increased levels of
cortisol to mobilize glucose into the bloodstream when stressed. This is
quickly followed by a rise in insulin levels, re-storing the glucose, to
rebalance those circulating glucose levels. This quick rise and subsequent drop
in blood sugar can leave us craving another quick form of relief from a quickly-metabolized sugar source.
As I’m sure you are exceedingly aware by now, psychosocial
stress throws our bodies into a biological stress response a great many times
in our modern era - most often without a physical means of energy expenditure
to match. When work has us mentally running rampant and time is not on our
side, we may find that a quick snack loaded with sugar holds us over just enough
to make it through the day. Our brains employ a large amount of glucose to
operate, but do not directly store it itself, so it must have a consistent supply
from the blood. Heavy mental work can prompt a craving for sugar; that spike
of energy may get the job done. However, continuing this pattern can lead to
serious dysglycemic conditions, defined as a imbalance in sugar metabolism and
energy production, characterized my abnormal blood glucose levels and
associated with related diseases.
If this glucose yo-yoing keeps up a number of conditions can
ensue. The first of which is hypoglycemia, literally referring to decreased
amounts of glucose in the bloodstream. This is commonly associated with
individual with diabetes but can be caused by a number of other reasons,
including drug-related side effects and fasting. What we are concerned with here though is hypoglycemia in reaction to eating, specifically refined sugars. After
a spike in glucose from a refined sugar, insulin takes effect, moving the
glucose out of the bloodstream. In many cases, this results in an abnormally
low level in blood sugar. If this effect is frequently occurring, we’ve got a
hypoglycemic condition.
Hypoglycemia is often associated with insulin resistance in
which beta-cells overproduce insulin and cause hypoglycemic conditions. Though
insulin resistance syndrome is thought to involve a variety of genetic,
lifestyle and dietary factors, psychosocial stress seems to play an important
role in its emergence. Human clinical studies have linked chronic stress to
enhanced sympathoadrenal reactivity, which increases fasting levels of glucose,
insulin and lipids. Chronic stress has also been connected with a reduction in
insulin-like growth factor-1 (IGF-1), the reduction of which is linked to glucose
intolerance. Additionally, chronic stress has shown numerously to have a
relationship with insulin resistance. The underlying mechanism between
psychosocial stress and insulin resistance may include stress-related
elevations in proinflammatory cytokines, which have been related to symptoms of
depression, anxiety, cognitive impairment and traits such as anger, hostility
and aggression which have been touched upon in previous posts. (Innes, Vincent
& Taylor, 2007)
Insulin resistance syndrome is sometimes used synonymously
with metabolic syndrome, previously known as syndrome x, but this condition
actually describes multiple factors beyond just insulin resistance. Both,
however, are used as indicators for risk of diabetes mellitus (type-2).
Metabolic syndrome involves a group of risk factors for cardiovascular disease
and stroke as well, including abdominal/visceral fat deposition, high
triglyceride levels, low HDL cholesterol levels, high blood pressure and high
blood sugar levels.
And guess what? The body’s stress response, characterized by
the activation of the sympathetic nervous system and hormonal release of
glucocorticoids, further stress these factors because they are causally linked.
Psychosocial stress is significantly correlated with high blood pressure,
atherosclerosis, increased levels of circulating cholesterol and triglycerides,
increased blood sugar and fat deposition in the abdominal area.
References:
Innes, K. E., Vincent, H.K., & Taylor, A. G. (2007).
Chronic Stress and Insulin
Resistance-Related
Indices of Cardiovascular Disease Risk, Part 1:
Neurophysiological
Responses and Pathological Sequelae. Alternative
Therapeutic
Health Medicine. 13(4) pp 46-52. Retrieved from
http://www.alternative-therapies.com/at/web_pdfs/innes.pdf
Sapolsky, Robert M. (2004). Why Zebras Don’t Get Ulcers: The
Acclaimed Guide to
Stress,
Stress-Related Diseases, and Coping. New York: St. Martin’s Griffin
Press.
Serwach, Joe (2006). Bitter Truth: Stress Drives Sweet
Craving. The University
Record
Online: The Regents of the University of Michigan. Retrieved
From
http://www.ur.umich.edu/0506/Apr17_06/04.shtml
No comments:
Post a Comment