Hypoglycaemia and Awareness Flashcards
symptoms of hypoglycaemia
what blood glucose levels are indicative of hypoglycaemia
<4 mmol/L is an alert value
<3 mmol/L is significant hypoglycaemia
however, it is often found in T1DM that BG levels of around 3.9 are common and not found to be dangerous
explain the progression as BG decreases
- 3 - decreased endogenous insulin
- 8-3.3 - production of glucagon and adrenaline (stress hormones) as a counter regulatory response
- 8 - symptoms appear and time for corrective action
<2.8 - impaired cognition
why is it that patients with good glycaemic control can still have widely flucctuating blood glucose levels
set amounts of insulin are injected - less accurate
often the ability to produce glucagon is lost, there is no counter regulation for low blood glucose levels
the BG level at which one produces insulin drops
why are T1DM patients at more of a risk of a hypo
the BG level at which symptoms of hypo and stress hormones are produced drops - this means that patients present/are diagnosed later with hypoglycaemia, and so there is less time for corrective action and coma state is reached quicker
severe hypoglycaemia
when hypoglycaemia leads to seizures, unconsciousness or the need for external assisstance
high morbidity and mortality risk
what is the limiting factor to good glucose contro
hypoglycaemia
as HbA1c levels improve - incidence of severe hypoglycaemic episodes increase
however, incidence of micro (and macro in T1DM) complications decrease
when are the risk times for hypoglycaemia
during sleep - body is thought not to counter regulate glucose changes
who are severe hypoglycaemic episodes common in
age 2-6
non hispanic black
lower annual household income
no private health insurance
longer duration diabetes
high HbA1c ( as a marker of non-compliance)
MDI (basal/bolus) regime
how has the prevalence of hypoglycaemia in T1DM changed over he past 20 years
it has not
what effect does intensive presciptive treatment have on hypoglycaemia
impaires defense against it
impaired hypoglycaemia awareness
the symptoms experienced with hypoglycaemia are not consistent, and in particular alter over time
the inability to detect hypoglycaemia is now referred to as hypoglycaemia unawareness
what is IHA defined as
when hypoglycaemia occurs (<4mmol/L) and the patient feels normal/no symptoms
who does IHA more frequently occur in
those who frequently have low blood glucose episodes
long duration T1 or T2 DM
intensively treated T1DM - low HbA1c
at what glucose level does cognitive dysfunction occur
2.8 mmol/L
at what glucose level are counter regulatory hormones released
eg glucagon and adrenaline
3.8 mmol/L (4 hit the floor)
maladaptive response to repeated hypoglycaemia
every time one has a hypoglycaemic episode, they become slightly less responsive to the next episode
one hypoglycaemic episode always predisposes one to another episode
- vicious cycle
compare the hypoglycaemic response of T1 and T2 DM patients
T1 - hypoglycaemic response at lower levels of BG and are less responsive
T2 - hypoglycaemic response at higher levels of BG than normal
low glucose in patients without diabetes
first switch off endogenous insulin secretion
hypoglycaemia stimulates glucagon and other counter regulatory hormones
symptom awareness and cognitive function
low glucose in patients with T1DM and IAH -summary
insulin cannot be switched off and counter regulatory and symptom response are both diminshed in intensity and occur at lower glucose levels
= window between recognition of hypoglycaemia and the ability to take action before condition is significiantly impaired is reduced, leading to a risk of much more severe hypoglycaemia
habituation??
habituation
becoming tolerant and adapted to a single process
immediate treatment of hypoglycaemia
consume 15-20g of glucose or simple carbs
recheck BG after 15 minutes
if hypoglycaemia continues, repeat
once BG returns to normal, eat a small snack if your next planned meal/snack is an hour/two away
treatment of severe hypoglycaemia
glucagon 1mg injection into arm, buttock or thigh
individual may experience nausea or vomiting when they regain consciousness
what conditions can cause primary failure of hormones to raise glucose
hypopituitarism
adrenal cortical failure
isolated GH deficiency
