Perhaps he is referring to this:

The overall mortality for sex-reassigned persons was higher during follow-up (aHR 2.8; 95% CI 1.8–4.3) than for controls of the same birth sex, particularly death from suicide (aHR 19.1; 95% CI 5.8–62.9). Sex-reassigned persons also had an increased risk for suicide attempts (aHR 4.9; 95% CI 2.9–8.5) and psychiatric inpatient care (aHR 2.8; 95% CI 2.0–3.9)

EDIT: This study doesn't really answer the relevant question. See this comment by hyporational.

Not suicide rates, but Wikipedia has some information along similar lines here.

I got this from this blog post by Eric Raymond who got it from this article which sites, but doesn't link to, statistics that suicide rates among those who have reassignment surgery are the same as among those who are denied it.