CHAPTER 2 WHAT CAUSES PCOS?

      The search for the underlying cause of PCOS is ongoing. Here’s what researchers have uncovered so far.

      IT’S ALL IN THE GENES!

      Researchers have noticed that PCOS tends to run in families, and a number of studies¹ suggest that genes play a part in developing the syndrome. A gene is a basic unit of heredity; bits of DNA that direct the reproduction, growth and function of cells. Symptoms are fairly easy to track down through the generations. There may be early male-pattern baldness in men (where the hairline recedes at the front and on the crown) and PCOS symptoms in women. The long-term health risks of PCOS – such as diabetes, high blood pressure and obesity – can also be seen in both sexes, and it’s thought that if a woman has PCOS, then her immediate family members have a 50–50 chance of having it too.

      CAN GUYS HAVE PCOS?

      Some researchers believe that the PCOS gene can be passed down in men as well as women. Obviously it’s harder to diagnose in men, because they don’t have ovaries and don’t have periods, and what would be considered hirsutism (excess hair) in women would be considered normal hair distribution in men. Still, a number of different findings have suggested a pattern of symptoms which, if found together, may represent the male counterpart of PCOS:

      All this is currently speculative, but the signs that link some aspects of PCOS to male relations² of women with PCOS adds weight not only to the pattern of inheritance theory but also to the ongoing argument against the appropriateness of the current name for the broad spectrum of symptoms associated with PCOS.

      PCOS also seems to be more common among women from southern Asia than in white Caucasian women, but no one yet knows why.

      Researchers are currently using gene technology to try and discover if any specific genes trigger PCOS. They need several hundred families to take part and the process can take decades. So far, studies that have concentrated on genes controlling oestrogen and progesterone have found no genetic link. But an interesting 1997 study³ showed that in PCOS a faulty gene may be involved in the first stage of testosterone production, and could account for the raised levels of this hormone often seen in women with PCOS. It’s possible that this gene may interact with other genes and with the environment to produce PCOS. Another study⁴ revealed that there may be a link between a specific variation in the insulin gene and the failure to ovulate in women with PCOS.

      Other research suggests that PCOS may represent the final outcome of different, deeply inter-related genetic abnormalities and environmental factors that influence each other and perpetuate the syndrome.⁵ Most women dealing with the condition believe this to be true. We all know that if we’re stressed or put on weight or don’t exercise, it affects our symptoms.

      Research into the genetics of PCOS continues – but what’s in it for us? If we can discover what genes trigger the syndrome, medical companies hope to develop medicines based on this knowledge, and perhaps even tests that can show very early on in life whether a person has PCOS or not, so you could create a diet and lifestyle to combat the problem, right from the start.

      ‘The biochemistry of PCOS is fascinating – but even more gripping is the realization that here is a genetic condition where, although there is no cure, sufferers can control the outcome through diet and lifestyle,’ says Dr Adam Carey, reproductive endocrinologist and nutritionist. ‘It is a condition where women really can use their environment to interact with their genetic programming and create a positive outcome.’

      TOO MUCH MALE HORMONE?

      Another theory about what causes PCOS is that women with the condition produce too much testosterone – a hormone known as the ‘male’ hormone because men produce 10 times more than women. In PCOS, the excess testosterone finds its way into the body’s circulation and triggers the familiar PCOS symptoms of hair loss, facial hair and acne. Testosterone can also be converted into oestrogen in the fat stores of the body. The result: weight gain and hormonal havoc.

      It appears that a malfunction with the hypothalamus–pituitary regulation of the menstrual cycle in women with PCOS causes the release of abnormal levels of hormones, in particular testosterone. Not only do high levels of luteinizing hormone (LH) stimulate the production of testosterone in the ovaries, but when the ovaries aren’t working as they should they become thickened, and this thickening produces even more testosterone.

      Several studies have linked excess androgens (male hormones, including testosterone) with PCOS. Testosterone is the most often cited, but research⁶ has also suggested that PCOS may be the result of a surge of another male hormone, adrenal androgen DHEA. DHEA is responsible for the production of pubic and armpit hair in puberty. This has yet to be proved conclusively, but it’s interesting as many women with PCOS date the beginning of their problems from puberty, when male hormones first surge.

      ‘I was 15 when I first noticed something was wrong. My friends had mild acne, but my face exploded. My friends started their periods, but I didn’t.’

       Laura, 21

      Some experts believe that even you haven’t got high levels of testosterone you may become more sensitive to it if you have PCOS, and go on to develop symptoms associated with testosterone excess because of that sensitivity, rather than increased levels. This could explain why some women with PCOS don’t show high testosterone levels in blood tests, even though they have the symptoms.

      Testosterone is carried in the bloodstream by a protein called sex hormone-binding globulin (SHGB). Higher-than-normal insulin levels in the bloodstream can suppress the production of SHBG so that the amount of unbound (active) testosterone is raised – the reason why some women with high insulin levels (common if you’re overweight) can have signs of testosterone excess even when tests reveal a normal level in the blood.

      HOW MUCH IS TOO MUCH?

      The normal blood testosterone level in women should be around 0.5–3.5 nmol per litre (a small measure of a substance in a solution); in men usually 15–30 nmol per litre. Women with PCOS tend to have a testosterone level of 2.5–5.0 nmol per litre. If the level goes higher than 5.0 nmol then other problems such as congenital