CHAPTER 33: DIABETES MELLITUS
Clinical S/Sx
o T1DM- abrupt, although insulin secretion decline begins long before the symptoms
develop.
Classic manifestations (new onset):
Polydipsia
Polyuria
Wt loss
Hyperglycemia
Ketonemia or ketonuria
DKA = classic s/sx + fruity-smelling breath + drowsiness/lethargy + vomiting
Silent (asymptomatic) incidental discovery
o T2DM
Polydipsia
Polyuria
Hyperglycemia
Risk Fx and Associated complications
o T1DM
Genetic
abnormalities at six genetic loci
mutation of the hepatic transcription factor (HNFP-1 alpha) on
chromosome 12
defective glucokinase molecule on chromosome 7p
Autoimmune- destruction of islet cells -> beta cells destruction
Environmental- toxins, food antigen, viral infection
Race- idiopathic T1DM is common among African American or Asian American.
o T2DM
Obesity
Race- native americans, Asian americans, latinos, pacific islanders, african
americans
Sedentary lifestyle
Hypertension
Dyslipidemia
Family hx- 15% if both parents have T2DM
Gestational hx
Age
Genetics- have strong influence- chromosome arm 7q – insulin resistance
o COMPLICATIONS (all types):
Microvascular
Eyes, heart, kidneys, nervous system
Retinopathy with potential loss of vision
Nephropathy leading to renal failure
, Peripheral neuropathy with risk of:
o Foot ulcers
o Amputation
o Charcot’s joint
Autonomic neuropathy with:
o GI, GU, CV s/sx
o sexual dysfunction may occur.
Macrovascular
Atherosclerotic conditions which increases the risk of HTN,
abnormalities in lipid metabolism, abnormalities of platelet function,
and periodontal disease:
o Cardiovascular
o Peripheral vascular
o Cerebrovascular
Diagnostic Criteria
o Pre-diabetes
BG too high to be considered normal BUT does not meet criteria for DM
Impaired glucose tolerance (IGT) or Impaired fasting glucose (IFG)
IFG 100-125 mg/dL
IGT 140-199 mg/dL
HbA1c 5.7% - 6.4%
At risk for diabetes and CVDs and may have insulin-resistance syndrome
o T1DM and T2DM
4 tests used:
Acute symptoms of DM + casual plasma glucose ≥ 200mg/dL
Fasting plasma glucose (FPG) >126 mg/dL- most reliable
2-h post-load plasma glucose in an oral glucose tolerance test ≥
200mg/dL
HbA1c ≥ 6.5%
Tests should be:
confirmed on a subsequent day, unless (+) overt clinical s/sx
preferrable to confirm with the same test OR one that is considered
more predictive
If a repeated test is below the diagnostic criteria -> REPEAT TEST in 3-
6months.
Clinical S/Sx
o T1DM- abrupt, although insulin secretion decline begins long before the symptoms
develop.
Classic manifestations (new onset):
Polydipsia
Polyuria
Wt loss
Hyperglycemia
Ketonemia or ketonuria
DKA = classic s/sx + fruity-smelling breath + drowsiness/lethargy + vomiting
Silent (asymptomatic) incidental discovery
o T2DM
Polydipsia
Polyuria
Hyperglycemia
Risk Fx and Associated complications
o T1DM
Genetic
abnormalities at six genetic loci
mutation of the hepatic transcription factor (HNFP-1 alpha) on
chromosome 12
defective glucokinase molecule on chromosome 7p
Autoimmune- destruction of islet cells -> beta cells destruction
Environmental- toxins, food antigen, viral infection
Race- idiopathic T1DM is common among African American or Asian American.
o T2DM
Obesity
Race- native americans, Asian americans, latinos, pacific islanders, african
americans
Sedentary lifestyle
Hypertension
Dyslipidemia
Family hx- 15% if both parents have T2DM
Gestational hx
Age
Genetics- have strong influence- chromosome arm 7q – insulin resistance
o COMPLICATIONS (all types):
Microvascular
Eyes, heart, kidneys, nervous system
Retinopathy with potential loss of vision
Nephropathy leading to renal failure
, Peripheral neuropathy with risk of:
o Foot ulcers
o Amputation
o Charcot’s joint
Autonomic neuropathy with:
o GI, GU, CV s/sx
o sexual dysfunction may occur.
Macrovascular
Atherosclerotic conditions which increases the risk of HTN,
abnormalities in lipid metabolism, abnormalities of platelet function,
and periodontal disease:
o Cardiovascular
o Peripheral vascular
o Cerebrovascular
Diagnostic Criteria
o Pre-diabetes
BG too high to be considered normal BUT does not meet criteria for DM
Impaired glucose tolerance (IGT) or Impaired fasting glucose (IFG)
IFG 100-125 mg/dL
IGT 140-199 mg/dL
HbA1c 5.7% - 6.4%
At risk for diabetes and CVDs and may have insulin-resistance syndrome
o T1DM and T2DM
4 tests used:
Acute symptoms of DM + casual plasma glucose ≥ 200mg/dL
Fasting plasma glucose (FPG) >126 mg/dL- most reliable
2-h post-load plasma glucose in an oral glucose tolerance test ≥
200mg/dL
HbA1c ≥ 6.5%
Tests should be:
confirmed on a subsequent day, unless (+) overt clinical s/sx
preferrable to confirm with the same test OR one that is considered
more predictive
If a repeated test is below the diagnostic criteria -> REPEAT TEST in 3-
6months.
