Litholink and Cystine output

[kathjewell]

I just recently got my 24 hour Litholink urine test back. I have 658? cystine in my unrine from this study. I was on my medication during the 24 hour urine test. Is this good, bad, I do not quite understand? My Urologist seemed happy with the results as my ph was 6.58, and my output was good. I have not had a stone in a few months so I am doing well. The only thing I have changed is I am drinking a 32 oz Powerade Zeo everyday. They contain potassium citrate. My blood pressure has been very low lately, but no one seems concerned about that either. My Nephrologist told me to increase soduim. LOL MY Urologist disagrees. Can you explain the litholink results to me in regards to my cystine output a little better. I am the first patient my Urologist has had that has Cystinuria . Thanks. Katie Jewell

[DAVIDGOLDFARB]

Katie, the key we think, we hope, is to look at the cystine supersaturation (SS) or capacity. A supersaturation less than 1 is good. The lower the better. We don't know the best number yet. Higher than 1 is not good. The SS is measured and is influenced by urine volume, the concentration of cystine and the pH. So it is one number that takes into account all the contributors. The cystine capacity is a calculation that says how great the capacity of your urine for MORE cystine is. A positive number is good: it can hold more cystine. A negative number is less desirable: it says your urine can't hold any more, in fact your urine is giving up cystine. So a higher SS is associated with a LOWER (more negative) capacity.
The amount of cystine you have is not bad; I'd say that the average for Americans with cystinuria is about 1000 mg (= 1 gram). That might make it a little bit easier to get your SS to less than 1. Your pH is fair but could be higher but maybe with good volume, not too much cystine, it's good enough.

[kathjewell]

Thank you for your reply. I am going to get a copy of the results to compare to your information. Sincerely, Kathryn Jewell