Polycystic Ovary Syndrome: Impact of Lipotoxicity on Metabolic and Reproductive Health

Abstract

Importance: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. Women with PCOS are at increased risk of developing several metabolic and reproductive abnormalities, including metabolic syndrome. Underlying the combined metabolic and reproductive dysfunction is lipotoxicity, defined as the ectopic deposition of lipid in nonadipose tissue where it induces oxidative stress linked with insulin resistance and inflammation.

Objective: To examine what metabolic components underlie insulin resistance in PCOS, how lipotoxicity through insulin resistance impairs metabolism and reproduction in these women, and why evidence-based, individualized management is essential for their care.

Evidence acquisition: PubMed search was performed using relevant terms to identify journal articles related to the subject. Relevant textbook chapters were also used.

Results: Polycystic ovary syndrome by Rotterdam criteria represents a complex syndrome of heterogeneous expression with variable adverse metabolic and reproductive implications. Women with classic PCOS are often insulin resistant and at greatest risk of developing metabolic syndrome with preferential fat accumulation and weight gain. Moreover, PCOS women may also have an altered capacity to properly store fat, causing ectopic lipid accumulation in nonadipose tissue, including the ovaries, where it can perpetuate insulin resistance and inflammation and harm the oocyte.

Conclusions and relevance: A personalized approach to managing PCOS is essential to improve the health of all PCOS women through cost-effective prevention and/or treatment, to minimize the risk of pregnancy complications in those individuals wishing to conceive, and to optimize the long-term health of PCOS women and their offspring.

FIGURE 1:

Differences between SC abdominal adipose of a PCOS woman with metabolic syndrome unresponsive to medical management vs. a normal ovulatory woman in adipocyte size, cell size distribution and adipose tissue macrophage (34) infiltration. Adipose of each woman was stained with hematoxylin and eosin (A and C); images were digitally scanned and quantified by automated image analysis software after manual cell circling. Adipocyte size was transformed using square root transformation, with a log value < 7.0 μm² (equivalent, 60 μm diameter) to identify a subpopulation of small adipocytes, (B and D); adipose tissue macrophages (ATMs) identifed by immunofluorescence as CD68/DAPI(+) cells were quantified by the same imaging system (E-F). Note the bimodaI adipocyte distribution of small and large adipocytes in the PCOS vs. the normal woman, along with increased ATM infiltration indicating inflammation. Black arrows, small or large adipocytes; white arrows, ATMs. Scale bars: 100 μm.