In this analysis of data from an unselected medically unbiased sample of women, 15.4% were found to require serum androgen testing in their evaluation for PCOS diagnosed by the NIH 1990 criteria (i.e., 'classic PCOS’). This finding supports the 2023 Evidence-based International Guidelines, which now recommend in their diagnostic algorithm for PCOS to test for biochemical hyperandrogenism and exclude other causes only in the absence of clinical hyperandrogenism.

While hirsutism has long been associated with hyperandrogenism, there is also evidence supporting the role of insulin resistance in this condition [19,20,21]. It is well-established that the presence of insulin resistance is associated with increased rates of other metabolic sequelae for PCOS patients [22]. As such, it is conceivable that its presence in the diagnostic framework of PCOS may portend an even greater quantity of prognostic information than serum androgen values. Moreover, androgen assays capture only a single moment in time due to the physiologic pulsatility of these hormones [23].

Various expert opinions have recommended use of the “highest quality androgen assays” for testing due to the small level of circulating androgens and the similarity in configuration between various sex steroids [6, 15]. The 2023 International Guidelines specifically recommend the use of validated, highly accurate tandem mass spectrometry assays for measuring total testosterone. However, as was acknowledged by Azziz et al. in their 2019 discussion of recommendations for epidemiologic and phenotypic research in PCOS, the cost and availability of quality androgen assays around the globe may, in some cases, be prohibitive for this purpose. The findings of this study provide support to their conclusion that being more selective in the use of androgen assays will not hinder, and is perhaps a preferable method to, detecting PCOS in large-scale epidemiologic studies of this condition.

Another important consideration in the evaluation of PCOS is cost – both in financial and human terms. In 2013, unnecessary services added $210 billion to healthcare spending in the United States [24]. Azziz et al. estimated that in 2004 dollars, the total cost of lab work alone for evaluation of PCOS was $737.54 ($1,366.35 in 2023 dollars) per patient [14]. Beyond this, the intangible costs to patients of delayed diagnosis and emotional uncertainty take a well-documented toll on mental health [25,26,27]. By phenotypically stratifying patients, as was done in this study, physicians can more expediently communicate to patients their diagnosis of PCOS while also more efficiently and effectively completing their evaluation.

Racial differences in the diagnosis of PCOS remain a complex topic of study given inherent differences in characteristics such as hair growth pattern and BMI as well as systematic healthcare disparities, epigenetic factors, and the complex role of socioeconomic and cultural influences [2, 18, 28]. The finding in this study of higher levels of hyperandrogenemia among oligomenorrheic White women as compared to Black women appears to be novel, however, it remains unclear whether this findings is generalizable to a larger patient population. Research by VanHise et al. has explored the complex interplay of regional, sociodemographic, and racial factors in the expression of PCOS phenotypes [29]. Their study found that hyperandrogenemia was more common among Black women in California than in Alabama, perhaps suggesting that environmental factors play a role in this diagnostic criterion. It is clear that further research is needed to evaluate the individual and combined roles of each of various racial and demographic factors in the development of PCOS as well as its various phenotypic manifestations and sequelae.

Our subgroup analysis by age suggests that the relative utility of biochemical androgen testing is higher in younger subjects who demonstrate oligomenorrhea without hirsutism. While our analysis is limited by a small sample size of women over 35, this finding is supported by prior studies that demonstrate a decrease in hyperandrogenemia associated with PCOS with advancing age [30]. This important limitation should therefore be considered in the evaluation of older women presenting with a complaint of oligomenorrhea without hirsutism, as the utility of serum androgen testing may be lower overall in this population.

Based on the results of this study, it is recommended that high-quality serum androgen assays be reserved for evaluation of PCOS in young women presenting with oligomenorrhea without hirsutism and may be considered in older (> 35 years) women with this presentation. Such an evaluation should be undertaken only after other causes of oligomenorrhea have been excluded by proper evaluation of factors such as TSH, prolactin, and 17-OHP, and possibly FSH and LH, in accordance with the 2023 International Guidelines [8]. Given the direct relationship between increased androgen levels and insulin resistance [31], when taken in consideration with the long-term health sequelae of untreated PCOS such as increased risk for endometrial cancer and cardiovascular disease [32], it is our recommendation that hirsutism be considered an appropriate proxy for serum androgen elevation in the diagnosis and treatment of PCOS. The impact of treatments varying from lifestyle modifications to hormonal and metabolic mediators on insulin resistance and adipose tissue dysfunction in PCOS is well-documented and should be considered early in the treatment of this condition to prevent adverse future health outcomes [33].

Our study benefitted from an unselected, medically non-biased patient population. Socioeconomic bias was also minimized in the study population, as subjects were selected from all staff seeking employment at UAB, which is the single largest employer in the city of Birmingham, and the largest public employer in the state of Alabama. The positions sought by subjects included custodians, secretarial staff, physicians, nursing staff, and a variety of other clerical and support staff. The use of an internal control group of eumenorrheic, non-hirsute women from which the upper-limit of normal for androgen values was established is another strength of this study.

The inclusion of subjects regardless of hormonal contraception, steroid administration, or insulin/glucose sensitization, or thyroid hormone therapy may, admittedly, have impacted results. It was estimated that from 2017–2019 approximately 17.1% of women aged 15–49 in the United States were using oral contraceptive pills, Depo-Provera, vaginal rings, or hormonal contraceptive patches – all of which would impact menstrual history, clinical hirsutism, and serum androgen levels [34]. An additional limitation of this study is the time period over which data was obtained. Since the initial data collection occurred over twenty years ago, it cannot necessarily be concluded to directly reflect current population trends. With the known rise in obesity incidence year over year in the state of Alabama [35], it is certainly conceivable that the incidence of PCOS has also increased. Research efforts to obtain updated data from a similar unselected population are currently ongoing at the original study institution. The study population included is also limited with regard to racial diversity. The vast majority of subjects were White or Black, with other minority races poorly represented. While this is fairly representative of the demographics of Birmingham as recently as the 2020 US Census [36], we recognize that it is not entirely representative of the US population at large.

It is worth noting that the 2023 International Guidelines uphold the Rotterdam 2023 Criteria for diagnosis of PCOS and consider the condition diagnosable in the presence of two out of the following three, after exclusion of other etiologies: 1) oligo-ovulation or anovulation, 2) hyperandrogenism, and 3) polycystic ovarian morphology. We recognize that the definition used in this study is only partially consistent, and far narrower, than that proposed in these guidelines. However, as the new guidelines recommend ultrasound evaluation if patients have only irregular menses or hyperandrogenism, then the categorizations of possible PCOS used in our results remain valid. Nonetheless, we acknowledge the potential utility of a future study analyzing the need for androgen assay in diagnosing PCOS using the 2023 International Guidelines. In this study, the addition of ultrasound would have been helpful for further characterization of subjects in Group 2 (OLIGO-ONLY) and Group 3 (HIRSUTE-ONLY), as those meeting criteria for polycystic ovarian morphology would, excluding other causes, be diagnosed with PCOS.

We conclude that stratification by clinical presentation, particularly the presence of hirsutism, to determine the need for circulating androgen measures is a useful tool in the diagnosis of PCOS. Furthermore, in an unselected patient population, less than one-fifth of patients required serum androgen assay in their evaluation. This finding is directly aligned with the recently published 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome [8]. These evidence-based guidelines state that the presence of hirsutism or clinical hyperandrogenism alone should be considered predictive of biochemical hyperandrogenism and PCOS in adults, alleviating the necessity for assays in all-comers. The findings of this study support a diagnostic algorithm in which serum androgen testing should only be performed in cases where clinical hyperandrogenism is absent, but other markers concerning PCOS are present, such as oligo-ovulation and menstrual dysfunction.