PCOS and Insulin Resistance: Part 4 How is PCOS diagnosed?
How is PCOS diagnosed? The only reason why this is important is because depending on whether you are given the PCOS “label” will determine how you are treated. Also, the “diagnosis” of PCOS allows for records showing the “incidence” of PCOS, i.e. how prevalent it is. Because of the challenges diagnosing PCOS, we don’t really have a clear understanding of how many women are afflicted by it. It is reported that about 10%-20% of women, worldwide, have PCOS, but it might actually be a lot more than that. Still, it is considered the most common endocrine (hormonal) disorder of women in their reproductive years. The prevalence of PCOS appears to vary from country to country, and it is believed that the number of women that will develop PCOS will likely increase with the growing obesity epidemic.
Figure 1 Comparison of Prevalences
Knowing that PCOS is intricately connected with Metabolic Syndrome, and the incidence of women with PCOS that have, or develop, Obesity, Diabetes and Heart Disease is quite high (as shown in the figure below, and better depicted in a previous blog) it is imperative that proper diagnosis and treatments be implemented for this growing number of women. Further, the current diagnostic criteria, is only adequate for diagnosing women during a certain period of their lives: the reproductive years. This is the period post-puberty until menopause. With the current diagnostic criteria, there is great “Difficulty in diagnosing women prepubertal, adolescence, menopause…” The need is certain in order to better understand incidence/prevalence but also to implement prevention and treatment of these very serious risk factors.
Figure 2 Prevalence of metabolic syndrome in women with PCOS
Sometimes, there is a sense of relief that comes with a diagnosis. “Finally, ‘something’ explains why I have acne, abnormal hair growth, am overweight, have emotional concerns, or…can’t get pregnant. It’s not my fault”. But how is the diagnosis of PCOS determined? There is much debate over the proper diagnostic criteria to label someone as having PCOS, there’s even debate over the name assigned to this syndrome. Many believe that the name PCOS (Polycystic Ovary Syndrome) does not adequately fit this syndrome. The deviant ovarian morphology, Polycystic Ovaries, aka PCO, is often seen on ultrasound studies of women with PCOS, and it is one of the diagnostic criterion. PCO, however, may be normal and is commonly seen in the ovaries of many women (especially young women) without the syndrome or any metabolic or reproductive abnormalities.
One of the biggest issues with the diagnosis of PCOS, is the determination of the criteria necessary to make this diagnosis. “All of the diagnostic criteria for PCOS have been based on expert opinion, the lowest level of evidence. None of these criteria were based on a formal consensus process”.
PCOS, a syndrome/affliction of women with concomitant metabolic and reproductive concerns, has been recognized and documented in medical literature since as early as the time of Hippocrates in the fifth century BC (yes, that’s BEFORE CHRIST). There have been many interesting names given, and observations made, to and about these women throughout history. In 1765, a 74-year-old woman was described as having “severe obesity and android (male) aspect (valde obesa et virili aspectu)”. In 1921, Achard and Thiers noted the “… coexistence of diabetes mellitus with clinical signs of androgen excess in a postmenopausal woman…”. Back then, this condition was commonly referred to as the “diabetes of the bearded women”. And yet, it wasn’t until the 1980’s, when some “landmark studies …” identified “… insulin resistance as a cardinal feature of the syndrome, (that) the metabolic sequelae of the disorder began to be appreciated.” In other words, there have been numerous observations throughout history that have shown that often women would present with metabolic concerns (diabetes, obesity, etc) while at the same time presenting with reproductive/hormonal (namely androgen excess) issues. It wasn’t until insulin resistance was identified as being an integral part of this syndrome picture that the metabolic/reproductive link made sense.
Previously to being labelled as PCOS (Polycystic Ovary Syndrome), this condition was most commonly referred to as Stein-Leventhal Syndrome, after the 2 American physicians who in 1935 first described and associated the presence of ovarian cysts and lack of ovulation (anovulation). As such, up until the 80’s PCOS, or Stein-Leventhal Syndrome, was diagnosed based on these 2 criteria: the presence of PCO (Polycystic Ovaries) and Anovulation. It is unclear when exactly the name in the medical literature was changed from Stein-Leventhal Syndrome to PCOS, but before that it was also known as Polycystic Ovarian Disease (not syndrome). As I mentioned above, there is some major concern in the medical community with this name (PCOS), as it puts an overemphasis on the PCO (Polycystic Ovary) symptom, which is not even the hallmark symptom of the syndrome, nor is it present in every patient with this condition.
After the 80’s there was renewed interest in attempting to properly identify and diagnose women with PCOS. “This renaissance of interest in PCOS created a need for a better working definition of the syndrome; an issue of that was addressed at the 1990 NICHD Conference on PCOS” At the NICHD (National Institutes of Child Health and Human Development), the potential diagnostic features of PCOS, were all put to a vote. It was then determined that hyperandrogenism (high androgen/male hormone levels) and chronic anovulation (with the exclusion of secondary causes) would became the 2 criteria necessary for the diagnosis of PCOS. These became known as the NICHD or NIH criteria. It is interesting to note that the NICHD criteria for diagnosis of PCOS (Polycystic Ovary Syndrome) did not include ovarian morphology (through ultrasound), meaning that according to this criteria, it was not necessary for a woman to have PCO (Polycystic Ovaries) to be diagnosed as having Polycystic Ovary Syndrome…
In 2003, a second conference on the diagnostic criteria of PCOS was held, this time in Rotterdam, and based on “expert opinion”, ovarian morphology was added to the previous NICHD criteria. After that, it was decided that the diagnostic criteria was “…to include at least two of the following (3) features: 1) clinical or biochemical hyperandrogenism; 2) oligo-anovulation; and 3) polycystic ovaries (PCO), excluding the same endocrinopathies.” The addition of the PCO (Polycystic Ovary), ovarian morphology, was most necessary at this time due to the already growing number of fertility treatments in women with PCOS. Women with this deviant ovarian morphology are at a higher risk of ovarian hyperstimulation syndrome, a serious side effect of ovulatory stimulation through fertility treatments.
As mentioned above, the differing diagnostic criteria influence the perceived prevalence of the syndrome. Under this new and broader criteria (Rotterdam), the incidence of PCOS went from 6-10% to double that (closer to 20%).
The Rotterdam criteria placed equal weight on all three features of PCOS: PCO, hyperandrogenism, and anovulation. In 2006, the AES (Androgen Excess Society) recommended that hyperandrogenism (excess androgen/male hormone levels) be considered the clinical and biochemical hallmark of PCOS combined with chronic anovulation and/or polycystic ovaries (PCO). As such, there are only 3 phenotypes, or different expressions, of PCOS according to this AES criteria:
Hyperandrogenism with anovulation (and no PCO)
Hyperandrogenism with PCO (normal ovulation) (potentially a transient phenotype)
Hyperandrogenism with PCO and anovulation
As such, in order to diagnose PCOS, “experts” use some combination of the above, (usually the presence of at least 2) oligo-ovulation, hyperandrogenism, and polycystic ovaries. Important to note here that even though insulin resistance, or disordered insulin action, has seen observed in as many as 70% of women with PCOS, Insulin Resistance is not a diagnostic criterion. Same goes for Obesity. Fifty to 80% of women with PCOS are obese, but obesity is also not part of the diagnostic criteria. PCOS lean women with normal insulin function that fit the above diagnostic criteria are thought to be a transient phenotype.
I mentioned in another blog that PCOS is considered a diagnosis of exclusion. This means that “To properly diagnose PCOS, clinicians need to exclude other endocrinopathies that mimic PCOS. These disorders include nonclassic adrenal hyperplasia, Cushing’s syndrome, androgen-producing tumors, and drug-induced androgen excess. In addition, clinicians should rule out ovulatory dysfunction from other causes, including thyroid dysfunction and hyperprolactinemia, as well as pregnancy in reproductive-aged women.” Clinically, these are called Differential Diagnosis.