define MDRD formula
this estimates the glomerular filtration rate based on creatinine and patient characteristics such as serum creatine level, age, ethnicity and gender
write down the MDRD formal
GFR = (140-age) x weight/ 7.2 x SCR x 0.742 x 1,21 - black American x 0/763 japans x 1.233 Chinese
what is Podocyturia
this referred to highly differentiated cell located in the outer membrane, they can become detached when put under stress in a proess called foot processes effacement
what is eGFR
estimulated glomerular filtration rate – test to check kidney function either by blood creatinine or a creatinine clearance test
- normal is 125
what is. Microalbuminuria and the different to Microalbuminuria
microalbuminuria is a moderate increase in the level of urine albumin, between 30-300 mg over 24 hours or 20-200mg/l macroalbumina is above 300 mg (same as proteinuria) the higher value -
= normal is 0-30
what is proteinuria
albumin excreteion is greater than 300mg in 24hr or ACR is greater than 30mg/mmol – poor prognostic marker
explain the results
- Albumin – this should not be filtered in the urine, detectable levels in the urine indicate leakage due to renal damage
- Creatinine – freely filtered by the kidneys build up of plasam creatinine indicates renal damage as they are not freely filtering it
- Glucose is freely filtered and should be reabsorped at the proximal convoluted tubule but if she is hyperglucaemic the transporters might not be able to reabsorb all the glucose and thereofre the glucose appears in the urine
- HbA1c level is high – indicates that there is prolonged elevation of plasam glucose over the last 30 days
- MDRD equals 40 - there are different stages where 90 being the worse, this means that she is on stage IIIb
- Blood pressure stage 1 hypertesnion but as she has the complication of diabetes she can be prescribed drugs
- Peripheral oedema – kidney not filtering correctly – glucose in the urine and kidney not filtering
how do you treat diabetic neprhopathy
- Medications to control high blood pressure
- Manage high sugar
- Lower high cholesterol
- Control the protien in the urine
- Then kidney dialysis
- Then transplant
how do you diagnose diabetic nephropathy
- Measure albumin in a urine dip/24 hour collection
- Measure the albumin/creatine ration ACR
describe the structure of the glomerulus
- Glomerular is made out of three layers
- Have the endothelium of the capillary, basement membrane, layer of epithelial cells containing podocytes that surround the outer surface of the basement membrane
- Allows the passage of water and solutes through feenstrations it he capillaries, pores in the basement membrane and gaps between the podocytes
- But prevents molecules larger than 60,000 from getting through such as albumin and proteins
how does the kidney prevent protein loss
- Negative charge on the endothelial cells prevent plasam protein passage
- Negative charge on the basement membrane from proteoglycans and podocytes
- Therefore if a molecule is negatively charged it does not pass through so filtration is restricted by size and charge of molecules
- Albumin is negatively charged and filtration is restricted by electrostatic repulsion
describe the pathophysiology of diabetic nephropahty
- Dibaetic damage causes glomerulo-sclerosis and thickening of the basmenet membrane
- Afferent arterioles become more vasodlated then efferent
- This increases the glomerular filtration rate and pressure and damages the capillaries through forces
- Mesangial cell hypertrophy and secretion of extracellular mesangial matrix leads to glomerulo sclerosis
what is diabetic retinopathy good for
- Retinal vessels are observerbal small vessels – damage in small vessels of retina indicates microvascular damage in the kidneys as well as the nerves – way of monitoring microvascular damage clinically
why are ACE and ARB given first
- ACE inhibitors
- Angiotensin 2 receptor blockers
- Cause efferent arteriolar dilation
- Reduce intraglomerular pressure/glomerular filtration pressure
describe the antihypertensive treatments
- Under 80 try to reduce blood pressure below 140/90
- Aged over 90 – try to reducte below 150/90
- Antihypertensive drugs – offer an ACE or ARB to adults – for black or afrocaribbean should consider an ARB instead of an ACE
- ACE not tolerated than offer an ARB
- Do not combine
- CCB or thiazide diuretic in addition to an ACE or ARB if they are not controlled be these alone
- Then offer all three
- Fourth antihypertensive or seek specialises advice
- Do not offer antiplatelet treatment in primary prevention of cardiovascular disease
Explain the presence of glucose in the urine
Glucose is freely filtered by the glomerulus, it is
present at plasma levels in proximal glomerulus
Specific sodium/glucose co –transporters enable
reabsorption of glucose
If above a certain threshold glucose cannot be fully
reabsorbed and appears in urine
what is the purpose of the MDRD formula
The Modification of Diet in Renal Disease study
equation
The MDRD formula enables the estimation of the
glomerular filtration rate
The estimated value depends on serum creatinine
levels,age,ethnicity and gender.
what does an elevated HbA1c mean
Elevated HbA1C indicates a prolonged elevation of
plasma glucose
Reflect plasma glucose levels in the past 30 days
Name 3 macrovascular complciations of diabetes
Diabetes is a risk factor for atherosclerosis
Stroke
Myocardial infarction
Gangrene
name 3 microvascular complications of diabetes
Diabetic Neuropathy
- Damage to vasa nervorum, and to Schwann cells
- Reduced conduction velocity (demyelination)
Sensory neuropathy
- First presents as loss of touch/pain/vibration sensation peripherally (toes first)
- Neuropathy advances proximally
- Eventually proprioception will be affected as well – falling over in the dark
- Painless blisters, ulcers
- Painful neuropathies are less common
- Present with burning/crawling pain in legs
- Improves with good glycaemic control
Autonomic neuropathy
- Postural hypotension
- Gastroparesis
- Erectile dysfunction
what is the target blood pressure for these patients
130/80
