Shortened Relative Leukocyte Telomere Length Is Associated With Polycystic Ovary Syndrome and Metabolic Traits

Background: Polycystic ovary syndrome (PCOS) is one of the commonest gyneco-endocrine disorders amongst women of reproductive age. Whether PCOS and cardiometabolic traits in PCOS patients are associated with shortened telomere length (TL) or relative leukocyte telomere length (rLTL) remains unclear. Methods: 214 women with PCOS and 214 age-matched women were recruited. rLTL was measured with an updated quantitative real-time PCR protocol and reported as Delta Delta Ct between telomere and a single-copy gene encoding beta-globin relative to a normalisation control. A two-way Mendelian randomization analysis using the UK Biobank Resource was performed to assess the causal relationship between rLTL and PCOS. Results: Women with PCOS had significantly shortened rLTL (PCOS: 0.5 +/- 0.7; control: 0.8 +/- 0.6; p < 0.001). Longer rLTL was associated with a lower risk of PCOS after adjusting for age, history of smoking and other cardiometabolic traits (OR: 0.503; 95% CI: 0.342-0.730; p < 0.001). Longer rLTL was associated with reduced risk of dyslidpidemia (OR: 0.563; 95% CI: 0.450-0.968; p = 0.042) in PCOS patients. PCOS subjects with rLTL shorter than mean of the rLTL of control subjects had an elevated risk of dysglycemia (OR: 2.09; 95% CI: 1.04-4.29; p = 0.040). No causal relationships were found between rLTL and PCOS in the Mendelian randomization study. Conclusions: Women with PCOS have significantly reduced rLTL and shorter LTL may be associated with cardiometabolic risk factors in PCOS subjects. There are no causal relationship between genetically determined PCOS and TL or vice versa.