June 1, 2008
Insulin, Other
Question from India:
I read the following about actions of insulin at Wikipedia: “Increased potassium uptake – forces cells to absorb serum potassium; lack of insulin inhibits absorption.” And, “Arterial muscle tone – forces arterial wall muscle to relax, increasing blood flow, especially in micro arteries; lack of insulin reduces flow by allowing these muscles to contract.”
So, can continual and increased insulin cause decreased urine exposure by changing some muscular tone in urinary system? It is obvious that if insulin lowers glucose levels, urine excretion can also be decreased. But I want to know its impact on changing muscular tone directly or indirectly. If insulin can cause decreased urine excretion, can creatnine clearance be effected due to it? I commonly feel such resistance in normal urine passage, on increasing insulin and reversal on decreasing it.
Answer:
The effect of filtered glucose outweighs all effects of insulin on the microcirculation in the kidney. In other words, if glucose levels go above 200 mg/dl [11.1 mmol/L] exceeding the ability of the kidney to reabsorb glucose, insulin does not have the capacity to change things that much in the small vessels. Remember also that hyperglycemia is associated with hyperfiltration and changes in creatinine clearance.
JTL
