Are hairy people hairy because of hormones (a lot of testosterone?) or it’s simply a genetic quality (assuming the hormones are affected by other factors)?
I’ll just go ahead and say that I always thought it was hormones, albeit most hairy people have higher levels of those particular hormones due to genetics. Obviously, if you are given some drugs which change the levels of those hormones in your body, you’ll be hairier, but if you aren’t on drugs it is probably your genes.
To reiterate: most of the time it is caused by genes that act via hormones.
Anyway, thats what I think, but let’s see if somebody comes by who knows.
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Men get more body hair when they gain weight, or so I read somewhere.
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There was a study someplace that found that nose hair - or was it ear hair? - correlates with heart attack rates in men, and I think they speculated it was just because both track with testosterone level.
Hormones permit the expression of hairy-ness, but first you gotta have the genes to produce the hair.
You may or may not have noticed, but people of Asian (east and southeast Asian, not most south Asian) descent tend to have very little body hair. People who are of pure Native American descent have no body hair other than that which grows at puberty, and the men also are/were beardless.
If you are thinking about someone who has a lot of body hair, that’s genetic, and (unless there’s a lot of body hair if the families of both parents) has 50% odds of passing it on to a child. Of course, if such a person mated with a person of (pure) Asian or Native American ancestry, the child would have expression of the body hair genes partly or wholly suppressed.
Well the dichotomy you’re trying to make between hormonal and genetic causes is basically false, since on the simplest level genes control hormone production and hormones in turn control genetic transcription. They are - to use a term I usually hate - “inextricably linked.”
That being said, you’re driving at a legitimate distinction. There’s a difference between hirsutism - which is male-pattern hairiness associated with androgens (male hormones) vs. hypertrichosis, which is excess hair growth all over the body that leads to a general “furriness”. Hypertrichosis can occasionally be related to hormones (for instance thyroid hormone) but it tends to be familial, while hirsutism (diagnosed only in women) tends to be associated with alterations is androgen production or sensitivity.
So very roughly, if you’re looking at a woman with a mustache you’re probably looking at some androgen issue which may or may not be congenital. If you’re looking at a generally furry person who just has hair everywhere that’s much more likely to be a congenital propensity unrelated to hormones.
This seems unlikely. As a general tendency, both more hair and weight gain are functions of age, but I can’t imagine the mechanism that would coordinate them.
I am naturally fairly hairy for a woman, and in comparison to my mother and my sister. I assume that I have inherited this from my father, who is a hairy manbeast. Women with olive skins (Italian/Spanish origin, for example) tend to have darker and more noticable body hair than Scandinavian women or Japanese women, so again, that’d be genetics.
However, I have an endocrinology problem that has many different symptoms, including hirsuitism (I’m now turning into a hairy manbeast just like dear old dad). An increase in testosterone, plus a sensitivity to testosterone and androgens, means that in certain areas of my body my lovely fine lady hairs turn into horrid dark man bristles. That is a hormonal issue. I am fighting against beard growth because of an inbalance in my hormones, not because I’m genetically predesposed to growing a beard - I’m the first bearded lady in the family. Laser hair removal often does not work for women with my problem as the hormonal imbalance remains, so simply turns the hair right back into bristles again.
So, my slightly informed answer would be that it’s a bit of both: you inherit a likelyhood to be either hairy or not, but hormonal issues can also factor in to a large or small extent.
Well, I can *imagine * a mechanism coordinating both. Androgen levels and central adiposity have a complex interaction, after all, and, in fact, it’s useful to think of obesity as an endocrinopathy. Certainly in women this is the case with PCOS which is associated with both weight gain and hirsutism. On the other hand in men, AFAIK visceral fat tends to be associated with hypogonadism if anything.
What causes PCOS (Poly-cystic Ovarian Syndrome)? I know that it is harmonal and that hirsuitism is a manifestism. But is the syndrome itself congenital? Can anything be done in childhood to prevent it from developing?
Are you familiar with false pregrancies associated with PCOS?
(Sorry for the hijack. Just don’t always have a chance to pick an uglybeech’s brain.
ugly, don’t worry. I am post everything. 
PCOS is probably multifactorial in cause. One thing, though, that does seem to be common among most sufferers of the syndrome is high levels of insulin.
A common cause of high levels of insulin is obesity, or even being mildly overweight. In particular, being overweight often leads to the body becoming insensitive, or resistant, to the effects of insulin to lower the blood sugar. In most cases, this leads to the body making more insulin in attempt to overcome, or compensate for, the insulin resistance.
Somewhat surprisingly, high levels of insulin, cause the ovary to make male hormone (testosterone). So, women with high insulin levels (who, by and large, are insulin resistant), may experience the effects of excess levels of male hormone. That can lead to unwanted hair growth for example.
But it’s even more complicated, at least when obesity is present. Specifically, all that fat tissue seems to suck up the chemical that normally binds to sex hormones such as testosterone. Normally, by virtue of that binding, the testosterone is rendered inactive. So, in an obese woman, because there is a lack of the testosterone binding chemical, any testosterone that’s around tends to be very effective, very potent. It’s not being bound and inactivated as it would be normally.
As you can see, then, it’s a double whammy - more testosterone and less of the testosterone binding chemical.
Getting back to the high insulin levels as a cause of PCOS and symptoms such as hirsutism, medicines that decrease insulin levels, will lead to a decrease in hirsutism. Typically, such medicine work by making the women’s body more sensitive to insulin. That causes a reduction in insulin level.
I’ll try to describe why there are “false pregnancies” in PCOS in my next post.
I assume by “false pregnancy” you mean a woman not having periods (amenorrhea), or at least having long intervals with no menstruation. Indeed, that is a symptom of PCOS which is especially likely to occur when the woman is obese (remember, not all PCOS women are overweight).
Realizing that fat tissue produces estrogen, it’s easy to appreciate that overweight women have more estrogen than normal (they get it both from their ovaries and their fat tissue). (As an aside, you may be aware that women who are overweight are more likely to develop breast and uterus cancer. Why? - because their extra fat tissue makes lots of estrogen. And, estrogen stimulates not just normal breast and uterus cells, but also pre-cancerous and cancerous breast and uterus cells.)
Getting back to false pregnancies and fat, the excess estrogen produced by the abdunant fat tissue in an obese woman, “maintains” the lining of the uterus. That is to say, that unlike the case normally, when a woman’s estrogen levels drops off after mid-cycle, and eventually fall so low that the lining of the uterus “dies” and sloughs off as a menses, a fat woman’s estrogen level may not fall off. Her uterus lining keeps surviving. She does not have a period.
Sidenote - My consultant (who is one of our leading endo research scientists) and my doctor both agree with what they’ve told me is the latest research in causes of PCOS: that it’s unlikely to be genetic (which had been previously thought) and that it’s more due to environmental factors. The current thinking AFAIK is that the cause for the recent explosion in the amount of women diagnosed with PCOS is due to the amount of crud that’s been in the modern diet since the 60s - antibiotics, hormones and pesticides. It’s why PCOS women should eat organic where possible. FWIW I’m the first woman in my family with PCOS so it’s unlikely it’s genetic in my case.
May I add the modifier “usually” to your first sentence here, as it certainly does not work in all cases. Most of them yes. Opinions are also divided on the “chicken and egg” factor of PCOS, as the vast majority of obese PCOS women with insulin resistance and testosterone/androgen problems report that they experienced symptoms of IR/testosterone increase prior to their weight gain. However, IANAD, I’m reporting what I’ve been told at clinic as a PCOS woman and what I’ve learned from my own research.
The Master Speaks:
Based on the incredibly hairy arms of the person on the Harley in front of me yesterday, I’d say motorcycle-riding has something to do with it.
And her boyfriend was no slouch in the body hair department either.
I won’t argue or agree. But, will note that you state that the insulin resistance comes before their weight gain. That is still totally consistent with the sequence I outlined (i.e. insulin resistance leads to high insulin levlels leads to hirsutism and the like). Who claimed weight gain must precede IR?
Cite, please?
If you want cites from me, I’ll give them. This is GQ. If you’re gonna give an opinion which is contrary to every standard endocrine textbook, paper, etc., it behooves you to give some cites. And, please, not from some self-proclaimed expert with no qualifications except testimonials on their own web sites.
I was responding specifically to where you said “being overweight often leads to…” and wasn’t actually disagreeing with you on that point but merely adding that anecdotal accounts from women with PCOS would suggest that IR often leads to being overweight rather than the other way around. I thought it was an interesting aside, perhaps I was incorrect.
I’m fully aware of what forum I’m in, thanks! As I’ve already stated, IAcertainlyNAD and am reporting on what has been told to me by my healthcare professionals, and wouldn’t have the slightest clue where to look for a cite. However, I received this information primarily from Professor S L Lightman , who certainly appears to know what he’s talking about (he was my first consultant when I sought medical advice on my PCOS). I’ve since had two GPs at my local practice confirm to me that they’ve read the same research, I think this was last year if that’s useful. As I’m unable to provide my own cites, everybody’s more than welcome to disregard my comments, which I thought I’d made clear by stating that the information I was providing was only AFAIK and that I’m NAD. I don’t expect anyone to take me terribly seriously in medical threads but I do have insight and information as a sufferer of hirsuitism that medical professionals do not: Textbooks aren’t always 100% accurate as I’m sure you’re aware.
Wouldn’t the amount of hormones be a function of genes?
And couldn’t RNA as well as DNA be a factor?
I do appreciate your candor and good will. Still, you said:
Asked for a cite about that totally unorthodox statement, you say that you heard it from Professor SL Lightman. You mention that two GP’s have “read the same research”.
Well, Professor Lightman is, indeed, an unimpeachable source. But I have to I wonder whether you misheard him. I don’t know about the GP’s. I say this since there is not one, not a single, solitary reference among the millions of medical research articles listed on PubMed that relates the cause of PCOS to antibiotics or pesticides. Not by Lightman, not by you, not me. Not a one.
I understand that you may not be able to use PubMed and similar resources. So, I invite the SDMB to find any reputable refeferences that would support your assertions.
Yep, sorry I can’t be more specific as I’d be interested in reading it, too. I got the impression that it was an article in a magazine, but couldn’t tell you whether it was ‘PCOS Weekly Fun Mag’ or what. I wasn’t aware it was a contentious issue, as 3 Drs talking to me about it lead me to believe it was widely known if not subscribed to. Apologies for any confusion.
A related question – are some nationalities/ethnic groups hairier than others? I know American Indians tend to have less than other groups. Just going by all the people I have known (I know, very small sample size, but please bear with me!), it seems like Turkish and Italian men have a lot more body hair than any one else. Am I way off-base for thinking this?