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Cardio Diabetes Medicine 2017 93

Stress Hyperglycemia or Diabetes -

Which is bad in ICU?

Dr. M. Jayapaul
MBBS, MD (UK) MRCP (UK) CCT (Int Med & Endo)
5/2 First Avenue, Sastri Nagar, Adyar,Chennai

Abstract Stress hyperglycemia or Diabetes – Which is
Hyperglycemia has been recognized as a common bad in ICU?
complication in critically ill patients with or without Hyperglycemia has been recognized as a common
diabetes. It was considered to be an adaptive re- complication in critically ill patients with or without
sponse to stress and believed to be beneficial. But, diabetes. Stress hyperglycemia is very common in
further observations noted that poorly controlled a hospital setting and a significant proportion of
glucose levels are associated with higher in-hospi- these patients have no history of previous impaired
tal mortality, prolonged hospital stay and increased glucose tolerance or diabetes. It was earlier believed
healthcare costs. Treatment with insulin therapy us- to be due to body’s adaptive response to stress
ing differing regimes and protocols had noted that or injury and hence considered to be beneficial to
glycemic control in acutely ill patients might improve the system. But further observations felt that poorly
morbidity and mortality. The main role of metabolic controlled glucose levels are associated with high-
response to stress is to maintain influx of substrates er in-hospital mortality, prolonged hospital stay and
to vital tissues. Brain is the major user of glucose in excess healthcare costs. Stress hyperglycaemia is
the fasting state and is independent of insulin. Tissue defined as a fasting blood glucose level ≥ 126 mg/
damage contributes to hyperglycemia and the most dl or random blood glucose ≥ 200 mg/dl without a
important factor is known history of diabetes. The threshold for hospital
the release of stress hormones such as adrena- related hyperglycemia in a patient with diabetes re-
line,noradrenaline, cortisol, growth hormone, inter- mains to be established. But for a patient with good
leukin-1 and tumor necrosis factor alpha. Sepsis glycemic control with HbA1c of 7 % any high glucose
and other factors also aggravate pre-existing insulin levels more than the expected range would be con-
resistance, which worsens,hyperglycemia. Evolving sidered as hyperglycemia. Recent studies have sug-
data suggest that stress hyperglycaemia may be gested that new-onset hyperglycemia carried an 18
more dangerous than hyperglycemia in a patient with fold increased risk of mortality when compared to
pre-existing diabetes. There is good evidence that patients with normoglycemia(1). Evidence suggests
aggressive management of glycemia during man- that insulin therapy to control stress hyperglycemia
agement of myocardial infarction, acute coronary can reduce mortality and improve patient outcomes.
syndromes and stroke is beneficial. Other studies
examining the benefits of intensive glucose control Normal glucose homeostasis
in sepsis failed to improve morbidity or mortality. Glucose is the primary energy source for most cells in
Glucose control in an intensive care setting is chal- the body. Glucose is absorbed in the small intestine
lenging in an ill patient with multiple co-morbidities via a sodium dependent active transporter – SGLT1.
and multi-organ dysfunction but may be needed with Following absorption into enterocytes, glucose enters
meticulous care to avoid hypoglycemia. the portal circulation and is transported to the liver.
The main processes of glucose metabolism such as
glycolysis, glycogenesis, glycogenolysis and gluco-
neogenesis all happen in the liver. These metabolic

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