May 082014
 

CC BY 2.0) - flickr user stevendepoloA little belated, but here’s the GSM health news that came out around April this year, in no particular order…

  • There was a new meta analysis of intestinal vaginoplasties published in April. This meta analysis overall found that rate and severity of complications was “low”, with stenosis the most common complication. There were no reports of cancer. Sexual satisfaction was high, but there were no quality of life measures reported. Quality of studies were reported to be low, though, and there was a distinct lack of use of standardized measures. Source.
  • Oncology Times released a review of cancer and cancer screenings in transgender people. Highly recommend you take a look at the source.
  • A study finds that trans men on testosterone have lower levels of anxiety, depression and anger than trans men not on testosterone. Source.
  • A review of current hormonal transition effects and aging determined that, based on current data, “Older [trans people] can commence cross-sex hormone treatment without disproportionate risks.” They note that monitoring for cardiovascular health is especially important for trans women, especially those who are on progesterones. Strength or type of hormones may need to be modified in order to minimize risk. Source.
  • As much of the sex positive community has known for a long time, the BMI of cis women is (in general) not correlated with sexual activity. Source.
  • In Croatian medical students knowledge about homosexuality was correlated with positive attitudes. Source.
  • Science is awesome! The Lancet reported success in engineering vaginas for 4 women with MRKHS. No complications over the 8 years of follow up, and satisfaction with sexual functioning. Fingers crossed that this technique can be used in the future for many more women! Source.
  • Remember that sexual orientation is not the same as behavior? In a recent analysis of previously collected data, 11.2% of heterosexual-identified sexually active (presumably cisgender) women reported ever having a same-sex partner. Another way of looking at it: 1 in 10 straight women have had sex with another woman. Source.
  • Don’t forget about aftercare and cuddling! Post-sex affection appears to be correlated with relationship satisfaction. Source.
  • Unsurprising but sad: Young LGB people are more likely to binge drink alcohol when they’ve been exposed to discrimination and homophobia. Source.

 

Dec 302012
 

Three researchers have proposed a new hypothesis for a biological cause of homosexuality. Attempts to find a “gay gene” have so far been inconclusive. This group of researchers theorized that it was epigenetics instead. Epigenetics are the meta level of genetics. Where genetics is the raw components of DNA (the C’s, T’s, G’s and A’s of the DNA strand), epigenetics is the packaging (e.g., histones) and/or temporary modification (e.g., DNA methylation) of DNA.

Essentially, these researchers hypothesize that epigenetics influences the responsiveness of a fetus to hormones they are exposed to in the womb (fetal hormones). Fetal androgens, like testosterone, masculinize the fetus at high levels (or feminize the fetus by their absence). The masculinization/feminization then somehow leads to being gay, maybe through effects on brain structure.

Technically speaking, it’s a good hypothesis; it’s testable and it’s disprovable. They even go so far as to list specific predictions based on their hypothesis. Good science. However, I’m troubled by their hypothesis. Namely, I don’t think there’s sufficient evidence that fetal masculinization/feminization results in non-heterosexuality.

It is known that fetal androgen exposure is associated with gender non-conforming play in childhood. That is, fetuses exposed to higher levels of androgens are more likely to become children who participate in “masculine” play (e.g., rough-and-tumble physical games) than fetuses exposed to lower levels of androgens. Studies of children with congenital adrenal hyperplasia are some of the strongest evidence I know of for this.

Is gender non-conforming play in childhood associated with adult homosexuality? Some studies have found that it is, but those studies were retrospective. That means that researchers had the participants report on their play preferences as children (through memory, videos, records, etc). Retrospective studies are very subject to confirmation bias! A much stronger study would be prospective (e.g., assign a cohort of children into groups based on their play preferences, and follow them until they’re 18 and ask them to report their orientation). Prospective studies don’t have the whole “20/20 hindsight”/confirmation bias problem.

The idea that fetal androgens levels affect sexual orientation also ends up reinforcing the stereotype of “gay men are feminine and lesbian women are masculine.” There’s very little evidence to support those stereotypes on the biological level. Besides, if the fetus’s brain is masculinized/feminized by fetal androgens, wouldn’t you expect a transgender child and not a gay one?

There’s a lot more to this study, so if you want to read through it yourself, the full article is available. It was published in The Quarterly Review of Biology, Dec 2012 issue.