what substances should be measured to gauge diabetic control?
Glycated haemoglobin (HbA1c)
lipid: triglycerides, LDL, HDL, total cholesterol
what are the three main reasons for testing blood glucose in diabetes?
-to adjust therapy to maintain normal glucose levels
-interpreting symptoms and signs
-to assess risks of tissue complications
what samples can be taken to measure glucose? (6)
what does Fehling's test do? when was this used?
reduces CuSoโ which precipitates as CuโO in the presence of an aldehyde in urine
what are the problems with measuring urine glucose?
-renal threshold can differ between patients and also individually
-fluid intake affects the urine concentration
how much lower is whole blood glucose compared to plasma glucose? why?
it is affected by haematocrit
how can glycolysis be inhibited? does this cancel out the drop in glucose concentration?
no- there is still a 0.2-0.3 mmol/l drop
what measurement of glucose do meters usually take?
whole blood glucose but convert it to a plasma glucose equivalent
what is the reaction catalysed by peroxidase?
HโOโ + reduced dye --> oxidised dye (therefore coloured) + HโO
How many times a day should patients with T2DM which is controlled by diet/metformin/glitazone test?
don't need to
how far back does a serum fructosamine test reflect?
(or 2 weeks-lifetime span of albumin??)
what are the old and measurements for HbA1c? when did it change? when will we stop co-reporting?
old (DCCT) = percentage
(IFCC) = mmol/Mmol
stop in 2011
when is fructosamin testing particularly useful? example?
when glucose control is changing quickly e.g. in diabetic pregnancy
3 ketone bodies which are measured in diabetes?
-3 (orร)-hydroxybutyric acid
how are the ketone bodies formed in diabetes?
lack of insulin means triglycerides are broken down to fatty acids and glycerol.
Fatty acids are converted to acetyl coA which is converted to acetoacetic acid which can then be converted to both acetone and 3 (-hydroxybutyric acid.
what test are the strips and tablets for testing ketone bodies based on? what is it?
nitroprusside/glycine turns purple in the presence of acetoacetic acid/acetone
what is looked for when testing for renal function?
microalbuminuria (e.g. unrin albumin:creatinine)
how is continuous glucose monitoring carried out?
subcutaneously implanted enzyme electrode where glucose oxidase is immobilised
what is a problem with continuous glucose monitoring?
measures tissue glucose which lags behind blood glucose by 5- 15 minutes