alt Hacker NewsI've heard a theory that since the chickenpox vaccine for kids, natural exposure to the virus in the wild is way down, and our immune systems are more likely to forget about it. Not specific to men of course, but a possible explanation for an increase in shingles generally.
There's been a few studies that found increase in shingles as the chicken pox vaccine became more widespread in the US, actually. With the usual caveat that correlation is not causation.