35 year-old, white male here, poz for 10 years. I've noticed that I often have foamy/bubbly urine, especially when I haven't drank enough water. When I've googled it, many things come up about being a sign of protein in the urine. However, they also say a strong flow can cause this and doesn't necessarily mean anything. And, I posed this question to an HIV forum website with many long-term survivors. Most said they never heard anyone concerned over foamy urine.
My kidney function labs are always good. My BUN was always a 7 (the lowest number on the normal range). However, my last one was 9--still very much normal, but ticked up for the very first time. My estimated GFR on my lab report says all is okay. And, I recently had a urinalysis that came back okay. I've read HIV, itself, can cause kidney issues and not just meds.
I suppose having HIV makes one notice things they probably wouldn't otherwise. Someone asked me whether I have back pain or issues going to the bathroom. I've dealt with back pain for years, so it is hard to tell whether the pain is just normal back pain. And, I don't have issues going to the bathroom.
I guess I'm wondering if there was some issue, whether the normal labs would show it? Are there other tests that can be done? Or, is foamy/bubbly urine fairly normal and could just be due to a strong flow causing air? The foam/bubbles aren't coming out of the toilet or anything. But, it is pretty noticable. If I pee on the side of the bowl, this doesn't usually happen.
This observation is described by many, is unrelated to HIV infection, and can be caused by some of the things you mention. Given the normal urine/blood tests you have, I would not be concerned.