A short review found that women with polycystic ovary syndrome (PCOS) usually have higher blood levels of the peptide kisspeptin, and this is true regardless of whether they are lean or overweight.

Polycystic ovary syndrome (PCOS) affects 6% to 20% of reproductive age women and is the most frequent cause of anovulatory infertility. Its physiopathology may result in part from hypothalamic alterations in the pulsatile secretion of gonadotropin-releasing hormone (GnRH). The neuropeptide kisspeptin participates in the mechanism through stimulation of the hormone's production. The purpose of this study was to review the articles which compared kisspeptin levels in women with PCOS with those of controls. A systematic review of observational studies was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) recommendations. The selected studies encompassed a population of patients with PCOS and controls, whose serum kisspeptin levels were evaluated. The studies were retrieved from the Medline, Cochrane, and Embase databases, and four of them were chosen for the review. In most studies, the serum kisspeptin levels were higher in women with PCOS than in controls notwithstanding the BMI. One of the articles showed that circulating plasma levels of kisspeptin were significantly higher in women with PCOS whose BMI was lower than 25 than in obese and overweight women. Our data suggest a higher concentration of serum kisspeptin in women with PCOS irrespective of their BMI. Further experimental and clinical studies are needed to ascertain the role of kisspeptin in PCOS.