Cut-off levels for hyperandrogenemia among Samoan women: An improved methodology for deriving normative data in an obese population.

OBJECTIVE: To define biochemical hyperandrogenemia (HA) among a population-based sample of reproductive-aged Samoan women, taking into consideration their high BMI levels.

DESIGN AND METHODS: A secondary analysis was performed among a cross-sectional sample of Samoan women aged 25-39years (n=494) who were part of a larger genome-wide association study (GWAS) of adiposity. Women indicating pregnancy/lactation, hysterectomy, oophorectomy, cancer treatment, or use of contraceptive injections were excluded from the study. We analyzed the distribution of free androgen index (FAI) values to establish normative androgen data among Samoan women of reproductive age. Using the lowest tertile of body mass index (BMI), we defined HA as free androgen index (FAI) values >95(th) FAI percentile in that subsample. We compared the anthropometric and metabolic characteristics of women with HA to women with normal androgen levels.

RESULTS: HA was defined as FAI>8.5. Using this definition, 14% of women were classified as hyperandrogenemic. Women with HA had significantly higher average BMI values, abdominal circumferences, fasting triglycerides, and insulin levels as well as significantly lower adiponectin levels.

CONCLUSION: This study is the first to define normative androgen values among Samoan women with a quantitative assessment of the relationship between adiposity and androgen levels. The uniquely high BMI levels in the population not only provide important clinical insight into normative androgen values among Samoan women, but they also serve as references for the clinical assessment of HA, taking into consideration BMI, in other populations.