Pathogenesis of diabetes mellitus Flashcards
What does diabetes insipidus mean?
Passing lots of insipid urine - ADH insufficiency
List the diagnostic criteria for DM (all types)
- Fasting blood glucose (>126mg/dl- Fasting, >Need 2 abnormal tests )
- OGTT
- HbA1c
Fasting HbA1c values
5.7% and 6.4%.: Likely prediabetes
≥ 6.5% diabetes
OGTT results
Oral glucose tolerance test
- 2-hour glucose
<200mg/dl: normal
What are the symptoms of diabetes
P3- Polyphagia, Polydipsia, and Poluria
Define HbA1c and explain results
AGE (Hemoglobin+ Sugar complex)
Define gestational diabetes
women become very resistant to their own insulin, hyperglycemia by the end of 2nd trimester (1% to 3% of all pregnancy). Resolve spontaneously after delivery.
Which types of diabetes are insulin resistant?
Type 2
Gestational
Steroid-induced
Acromegaly
NB: patients often have very high levels of insulin in circulation
What auto-antibodies can be found in T1DM?
Islet cell autoantigen (ICA) 512
IAA (insulin auto-antibody)
GAD (glutamic acid decarboxylase)
What is the typical presenting history for T1DM
Child/adolescent history of weight loss, thirst, polyuria, nocturia, and fatigue HLA DR3 and 4 Viral illness recently High blood glucose level High blood ketones
Why does weight loss occur in T1DM
Glucose is not absorbed into muscles/fat cells from the blood
Results in both fat and muscle bulk
Which genes are likely to increase susceptibility to T1DM?
CTLA4 (Cytotoxic T-Lymphocyte Associated Protein 4), and PTPN22 (Protein tyrosine phosphatase, non-receptor type 22 ), and insulin gene VNTRs(variable number of tandem repeats).
Which other autoimmune diseases are associated with T1DM?
> Thyroid disease (hyper and hypo) V. strongly associated
Coeliac disease - strongly associated
Addison’s disease = primary adrenal insufficiency (hypocortisolism)
Pernicious anaemia
Inflammatory bowel disease (UC/Crohn’s)
Premature ovarian failure
Genes for DM 2
Transcription factor 7-like 2=TCF7L2
Peroxisome proliferator-activated receptor gamma=PPAR-γ or PPARG
Insulitis=
DM1
