I had my first appointment with the nephrologist (= kidney expert) today. To my great surprise, the appointment lasted one-and-a-quarter hours. The first 45 minutes was with an assistant doctor, who peppered me with questions about my diet and lifestyle. Then the nephrologist was added to the consultation.
Turns out the level of calcium in my mid-December "24-hour urine test" was extremely high: 433mg/day (the normal range would be 250 or lower). This is in the "red, danger zone" as far as kidney-stone formation is concerned. All of my other urine numbers were very good: "very low risk" of kidney stones.
Anyway, they are running a whole battery of additional tests (blood tests). There are various causation factors for "high calcium in urine" including Vitamin D and parathyroid hormone.
For what it is worth: When I had my first kidney stone in May, the calcium levels in my urine were normal (!!!). The decision today was as follows:
- Go immediately on a "low sodium" diet, which apparently is about the only dietary mechanism that could lower the calcium level ("low sodium" was defined as less than 2 grams per day). For what it's worth: the 24-hour urine test showed a "normal" sodium level i.e. I have not been over-doing the salt. But they now want me to go explicitly "low sodium."
- Re-assess a couple of months from now; the doctor was not very optimistic that I could lower my calcium levels sufficiently entirely with diet, but he wanted to give it a try.
- If it does not work: doctor suggests putting me on thiazides, a class of blood-pressure medication that also lowers calcium and which I would have to take for the rest of my life.
I was, in general, very impressed by the thoroughness of the appointment and their willingness to listen to my concerns, namely, that I firmly believe my kidney stones are very likely caused by my huge change in diet when I got the T2D diagnosis nearly one year ago. They are not rushing to "medicate" me and seemed genuinely interested in figuring out what is going on.
I am awaiting the results of the new tests.....
Edited later to replace "sodium" with "calcium" in the third bullet point in the "decision" paragraph.
Edited to add: When I told the doctor I had heard that thiazides increase BG levels, he said, "only at high doses." The dose he has in mind apparently would not have a major effect on BG....