Abstract and Introduction
Being the most common endocrinopathy of young women, polycystic ovary syndrome has much variation in its clinical expression based on ancestry. Ethnic differences of the phenotype are closely linked to its complex pathophysiology. This paper reviews data of the past three decades ensuring a precise diagnosis and taking into account underlying factors, effects of migration including heterogeneity, and diversity within each identified ethnic group. Differing expressions of hyperandrogenism, obesity, insulin resistance and metabolic manifestations of polycystic ovary syndrome occur among women from distinct geographic locations and ancestry. These ethnic phenotypes correlate with their inherent metabolic risks, skin sensitivity to androgens and social outlook that particularly affects their quality of life and health-seeking behavior. It is recommended that such ethnic variations are recognized in routine clinical practice and longitudinal data be maintained to study the true impact of such differences on disease outcomes.
Polycystic ovary syndrome (PCOS), the most common endocrine problem that afflicts young women all over the world, has the potential for much variation in its clinical expression, co-morbidities and management outcomes based on ethnicity. Although from the same species, the world's populations vary in physical, behavioral and social distinctiveness based particularly on ancestry and geographic segregation. Natural selection of genes and adaptation to environmental conditions has caused these variations, which in turn impacts disease phenotype. Additionally, sociocultural differences, particularly diet, impact on chronic diseases and their health-related behavior.[3,101] Therefore, the occurrence, manifestations and management problems of PCOS commonly encountered in clinical practice must be viewed within the context of the ethnic origin of the affected woman.
This review addresses the following on PCOS and ethnicity: how its defining characteristics (hyperandrogenism, anovulation, polycystic ovarian morphology) and subphenotypes differ among ethnic groups worldwide; how the metabolic risks differ based on ethnicity, both in their homeland and after migration to more developed countries; how the sociologic implications of its diagnosis vary among ethnic groups and countries in perceived quality-of-life, care-seeking behavior and preference for treatment modality. Standard biomedical classification of ethnic groups in the USA are black or African–American, Hispanic and non-Hispanic that includes whites and blacks, Asians, Native Hawaiian and Pacific Islanders, and American Indians or Alaskan Natives. This review of the world's populations will be on a continental basis: African, caucasian (Europe and the Middle East), Asian, Pacific Islander (Australian, New Guinean and Melanesian) and Native American.[3,4] Nevertheless, diversity within a given continent must be taken into account, especially in Eurasia – the world's largest landmass occupied by nearly two-thirds of its population.
The study of ethnic differences of PCOS requires in-depth analysis of its epidemiology that would also help decipher its complex etiology. This ideally entails an 'accurate' diagnosis and proper classification of ethnicity. However, a gold standard definition of PCOS is not possible due to symptom heterogeneity and lack of a unique phenotype. Therefore, a pragmatic approach to the diagnosis of PCOS using standard international criteria must be applied for this purpose to ensure that comparable groups of affected women are reviewed (Table 1).[5–7]
Furthermore, the phenotype of PCOS can vary over time in an affected woman, which is age and weight dependent. One must also be cautious to translate observed ethnic differences in small studies to reflect inherent characteristics of entire populations. Further, socioeconomic differences cause health disparities that can alter disease manifestation and complications, which must also be taken into account in the analysis.
Expert Rev Endocrinol Metab. 2013;8(1):71-79. © 2013 Expert Reviews Ltd.