Normal weight polycystic ovary syndrome (PCOS) women may have altered adipose structure-function underlying metabolic dysfunction.

This study examines whether adipose structure-functional changes exist in normal weight PCOS women and correlate with hyperandrogenism and/or hyperinsulinemia.

This is a prospective cohort study.

The setting was an academic medical center.

Six normal weight PCOS women and 14 age- and body mass index-matched normoandrogenic ovulatory (NL) women were included.

All women underwent circulating hormone and metabolic measurements; frequently sampled intravenous glucose tolerance testing; total body dual-energy x-ray absorptiometry; abdominal magnetic resonance imaging; and SC abdominal fat biopsy.

Circulating hormones and metabolites, body fat and its distribution, and adipocyte size were compared between PCOS and NL women, and were correlated with each other in all women.

Circulating LH and androgen levels were significantly greater in PCOS than NL women, as were fasting insulin levels, pancreatic β-cell responsiveness to glucose, and total abdominal fat mass. Intra-abdominal fat mass also was significantly increased in PCOS women and was positively correlated with circulating androgen, fasting insulin, triglyceride, and non-high-density lipoprotein cholesterol levels in all women. SC abdominal fat mass was not significantly increased in PCOS women, but contained a greater proportion of small SC abdominal adipocytes that positively correlated with serum androgen levels in all women.

Hyperandrogenism in normal weight PCOS women is associated with preferential intra-abdominal fat deposition and an increased population of small SC abdominal adipocytes that could constrain SC adipose storage and promote metabolic dysfunction.