Transcript Food for thought - Georgetown University

Diabetes (abridged!)
Who needs screening for DM?
Age >45
Obese – BMI >25
1st degree relative with DM
Racial groups:
–
–
–
–
–
African American
Hispanic American
Native American
Asian American
Pacific Islander
History of GDM – or delivered macrosomic baby
HTN
HDL <35, TG>250
Previous “pre-diabetes” or “impaired glucose tolerance”
i.e. Fasting BG 110-126
How should you screen?
Fasting plasma glucose is now the
recommended test.
Oral Glucose Tolerance Testing – measuring
glucose 2 hours after 75g glucose load – is no
longer necessary
HbA1c is used for monitoring but not for
screening
Need to have two separate readings of fasting
glucose >126
Symptoms of DM (polyuria, polydipsia, wt loss)
with random glucose >200
Treatment Goals
Pre-prandial glucose
80-120
2 hour post prandial glucose
<160
Pre-bed glucose
100-140
HbA1c <6.5 – 7%
Insulin
Daily insulin production is 24-30 units
In normal people insulin is secreted directly into
the portal circulation
Patients with Type I DM usually need 0.5-1
units/Kg
But dose depends on diet, stress and exercise
Stress hormones (Cortisol, GH,
Catecholamines) all increase insulin resistance
and in stressful situations you will need more
insulin.
Types of insulin
Name
Category
Time to
onset
Time to
peak
Duration
effective
Maximum
duration
Lispro
Rapid
(Humalog)
15 mins
30-90
mins
3-4 h
4-6 h
Aspart
(Novolog)
Rapid
15-30
mins
60-90
mins
1-3 h
3-5 h
Regular
Short
30-60
mins
2-3 h
3-6 h
6-8 h
NPH
Intermediate 2-4 h
6-10 h
10-16 h
14-18h
Glargine
(Lantus)
Long
No peak
24 hours
24 hours
Lente
Intermediate 3-4 h
6-12 h
12-18 h
16-20 h
Ultralente
Long
10-16 h
18-20h
20-24 h
2h
6-10h
Basal/Bolus regimen
Basal/Bolus regimen
– Daily insulin dose consists of a basal insulin to inhibit hepatic
glucose production and pre-meal insulin to cover intake
– Typically this is achieved with Lantus QHS and Novolog (aspart)
pre meals.
– Patients on this regimen should either be given a Sliding scale
instructing them how to cover their premeal accuchecks and how
to “Carb count” OR they need a standard dose of premeal insulin
which you review when you see them in clinic based on their
readings.
– 15g carbs = 1 unit of insulin
– Requires multiple insulin injections and accuchecks, but provides
greater flexibility in matching insulin to meal.
Other regimens
NPH or Lente at bed time and then regular
insulin to cover breakfast and dinner, but
risk of nocturnal hypoglycemia
70/30 insulin is a mixture of rapid acting
and more prolonged acting – can be used
in a bid dosing but allows less flexibility
with diet
Insulin Pump
Uses a continuous subcutaneous infusion of
Aspart, and the patient programs in boluses to
cover meals.
Still requires accuchecks, and although there
are now continuous glucose recorders the
technology does not yet exist to link these up
with the pump – but it is coming.
Aspart has very predictable absorption – so
easier to make the fine adjustments to regimen.
Pumps require a very proactive patient – they
are not for your non-compliant VA patients.
Oral Hypoglycemics
Class
Drugs
MOA
Reduction of
HbA1c
Sulphonylureas
Glyburide
Glipizide
Glimerperide
Chlorpropamide
Insulin
secretagogue
1-2%
Meglitinides
Repaglinide
Nateglinide
Insulin
secretagogue
0.8-1.5%
Biguanides
Metformin
Decresed hepatic
gluconeogenesis
1-2%
Thiazolidinedione
Pioglitazone
Rosiglitazone
Insulin Sensitizers 0.5-1.3%
α-glucosidase
inhibitor
Acarbose
Reduces GI
absorption of
carbohydrate
0.5-1%
Sulfonylureas and Meglitinides
Stimulate release of insulin in response to
glucose
Augment insulin levels
Meglitinides act rapidly and achieve good
post prandial control but are short acting
and have to be given with every meal
Sulfonylureas are longer acting and given
once daily but have risk of hypoglycemia
Metformin
Stimulates hepatic gluconeogenesis and
improves insulin sensitivity
Although its effect on glycemic control is not that
impressive, it does cause significant reduction in
cardiovascular disease
Does not cause weight gain
Main risk is LACTIC ACIDOSIS
– Should be avoided in pts with creatinine >1.4 due to
renally excreted.
– Hold drug 24-48 hours prior to contrast procedures
and do not restart until BUN/Creatinine documented
to be normal.
Thiazolidinediones
Bind to nuclear receptors affecting gene
expression and therefore have a long latency
requiring 4-12 weeks before they reach efficacy.
Beneficial lipid effects.
Pioglitazone has greater effect on TG and less
LDL lowering than Rosiglitazone.
Require LFT monitoring and should be stopped
if AST rises
Contraindicated in CHF due to fluid retention
α-glucosidase inhibitors
Reduce the rate of carbohydrate
absorption from the gut enabling
endogenous insulin to maintain glycemic
control.
Not absorbed and no weight gain, but
severe flatulence.
Caveats on oral hypoglycemic
Any oral hypoglycemic will only lower
HbA1c by 1-2 %
They do have additive effects, but if a
patients HbA1c is 10 – you will not be able
to achieve glycemic control with oral
agents alone.