GFR and Kidney Function Test
Glomerular filtration rate (GFR) is the volume of fluid filtered from the
renal glomerular capillaries into the Bowman's capsule per unit time. Glomerular
filtration rate (GFR) can be calculated by measuring any chemical that has a
steady level in the blood, and is freely filtered but neither reabsorbed nor
secreted by the kidneys. The rate therefore measured is the quantity of the
substance in the urine that originated from a calculable volume of blood. In a
word, GFR is used to examine the kidney function.
Calculated or measured GFR or creatinine clearance has a normal range of
90-120 ml/min. For convenience, this is referred to as 100% of kidney function.
For example, if GFR is 15ml/min, that is said to represent approximately 15% of
kidney function. GFR (or creatinine clearance) varies with age. There is
generally a slow decrease of about 1% of GFR/year from the mid thirties. So at
age 70 years, GFR on average is often only 60-70% of the normal.
When there is damage in the kidney, GRF will decrease, the level of which can
also divide chronic kidney disease into 5 stages. In stage 1, GFR is more than
90 ml/min. In stage 2, GFR is between 60 to 89 ml/min. In stage 3 of chronic
kidney disease, GFR is 30 to 59 ml/min. In stage 4 of chronic kidney disease,
GFR is 15 to 29 ml/min. In stage 5, GFR is less than 15 ml/min.
Why Uremia Patients Have High Blood Sugar
Why do uremia patients have high blood sugar? In uremia stage, people may
have decreased ability of sugar tolerance and slight high blood sugar when the
stomach is empty. It is mainly connected with two aspects:
One is peripheral tissue is not allergic to the insulin, which may be
connected with the insulin receptor and defection after receptor. One the other
hand, in uremia stage, the toxins accumulate into the body, especially the
parathormone can inhibit the function of beta cells, thus inhibiting the
compensary insulin secretion and lowering the reaction to high blood sugar. In
the end, the tolerance of sugar becomes abnormal.
In addition, acidosis accompanied by uremia is also one of the reasons.
Metabolic acidosis can inhibit the glycolysis of glucose, damage the usage of
glucose, disturb the effect of insulin to the surrounding tissues. Dialysis can
reverse the above mentioned disorder of sugar metabolism.
