Lecture 26: Clinical Biochemistry - Laboratory Tests in Diabetes Flashcards
1
Q
why use laboratory tests?
A
- diagnosis: confirmation or rejection of clinical diagnosis
- monitoring: natural history or response to treatment
- prognosis: prediction of course or outcome of the disease
- screening: detection of subclinical disease
2
Q
diabetes diagnosis blood results
random BG, fasting BG, 2hr BG, HbA1c
A
- random venous plasma glucose >/= 11.1mmol/L (200mg/dl)
- fasting plasma glucose >/= 7mmol/L (126mg/dl)
- 2 hour plasma glucose >/= 11.1mmol/L in OGTT (200mg/dl)
- HbA1c >/= 48mmol/mol (type 2 diabetes only)
- if asymptomatic, requires confirmation by repeat testing on another day
mmol/l x 18 = mg/dl
3
Q
do not use HbA1c for diagnosing diabetes in…
A
- children and young people
- suspected type 1 diabetes
- symptoms < 2 months
- high risk patients who are acutely ill
- patients taking medication that may cause rapid glucose rise (e.g. steroids)
- acute pancreatic damage
- pregnancy
- presence of genetic, haematological or illness-related factors that affect HbA1c and its measurement
4
Q
give examples of point of care tests that are performed to monitor a patient with acute diabetes
A
- urine testing: glycosuria, ketonuria
- glucose meter: measurement of capillary blood glucose (finger-prick)
5
Q
what is factitious hypoglycaemia?
A
high insulin levels in absence of elevated C-peptide concentrations
6
Q
what is an insulinoma
A
- elevated C-peptide level indicative of insulin secreting tumour = insulinoma
7
Q
which biochemical measurements are used to monitor chronic diabetes?
A
- glucose (self-monitoring)
- HbA1c (glycaemic control)
- urine albumin/creatine ratio (diabetic renal disease - microvascular screening)
- lipids (macrovascular screening)
8
Q
what does the albumin:creatine ratio measure?
A
- a high ratio indicates that albumin is being lost and excreted in the urine.
- healthy kidneys shouldnt do this.
- indicates kidney disease.
