Q: What is the most important clinical relevance of TTKG (The trans-tubular potassium gradient)?
Answer: TTKG is calculated by following formula
TTKG = urine K+ X serum osmolality/serum K+ X urine osmolality
- A TTKG of greater than 8 indicates that aldosterone is present and that the collecting duct is responsive to it.
- A TTKG of less than 5 in the presence of hyperkalemia indicates aldosterone deficiency or resistance.