wvalady1968: I had to Google this subject. As someone who has done literally thousands of urinalyses, I have to admit that one of the factors that we do NOT address is the presence of foam per se. After all, most specimens we receive are foamy and most samples don't test positive for protein.
While I didn't find anything concrete, this was interesting.
SUBJECT: Why does urine from males have more bubbles?
DATE: 6/96
Every quarter, I run a urine lab in my introductory Human biology course. After everyone gets over feeling uncomfortable by having others see their urine, it turns out to be one of the most popular labs we do. Interestingly, I usually get at least one female asking me the same question--quite confidentially. "Why is it that male urine seems to have more bubbles than female urine?"
My off-the-top-of-my-head response has always been in the method of collection. I suggest that males, perhaps because of greater force, or distance, are able to "blast" the sample and thus create more froth. A logical hypothesis, I thought, but never tested.
I could not think of a very accurate way to test the hypothesis, and still maintain the high standards of our institution and still retain my job. But last week, I figured out a way.
When the students returned to the lab with their samples in hand, I asked three males and three females if I might have a third of a test tube of their finest for a test I was going to run. They agreed, and the only identifying marks were the classic male and female symbols on the test tubes. Each test tube was covered with parafilm, and then each was shaken (not stirred) for five times (or 5 "shakes").
All three of the male samples created 2-4 cm. "heads," while all three female samples could only muster about 0.5 cm. worth of effort. After standing for 1 hour, the male samples still had about 1 cm. of foam, while the female samples were entirely bubbleless.
Obviously, the bubble factor of urine is not due to the method of collection, but shows a definite dimorphic difference. I realize that the sample size was small and the experiment lacked the proper elegance to be recorded in a journal. Still, while trying hard not to appear sexist, it does appear that males are better bubble-makers than females.
[Sorry, but I have no references for my bubble research.]
ED [XXXX]
DeAnza College
A possible answer to the bubble question. My mammalogy colleague suggested the detergent factor may be a result of naturally leaky accessory glands that males have and females do not. Again, there are no data to support this claim.
John [XXX]
Another thought it might be the beer that guys drink.
My secondary hypothesis is that some of the fluid from the bulbourethral (Cowper's) gland sneaks out with the sample putting a bit of mucus into the mix, causing the froth.
ED
DeAnza College
Date: 6/17/96 11:38 AM
To: Essie
From: Ed
Dr. Xxxx,
I got this in a biology lab list serve I watch. I thought you might find it interesting. Ed
I actually have not come across this matter in scientific literature of physiology but can make some educated guesses. Most likely it has to do with a higher secretion of detergent like compounds in the urine. It is quite likely that compounds such as deoxycholate that are products of cholesterol metabolism, which are detergents, are in part excreted in the urine and that these are produced more in males than females. Such detergent like compounds may produce foam and froth upon mixing with water.
Another possibility may be the production of C02; both C02 and bicarbonates are secreted in the urine and it is possible that these are produced more in the male than in the female. Please feel free to send these to the person who raised the question. It might help and hopefully it might be true. Thanks
Essie
[Edited to remove names and addresses, although a Google search could find them.] | 
