Cardiometabolic aspects of the polycystic ovary syndrome

Abstract

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age and is associated with various metabolic perturbations, in addition to chronic anovulation and factors related to androgen excess. In general, women live longer than men and develop cardiovascular disease at an older age. However, women with PCOS, as compared with age- and body mass index-matched women without the syndrome, appear to have a higher risk of insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia, and an increased prothrombotic state, possibly resulting in a higher rate of type 2 diabetes mellitus, fatty liver disease, subclinical atherosclerosis, vascular dysfunction, and finally cardiovascular disease and mortality. Further alterations in PCOS include an increased prevalence of sleep apnea, as well as various changes in the secretion and/or function of adipokines, adipose tissue-derived proinflammatory factors and gut hormones, all of them with direct or indirect influences on the complex signaling network that regulates metabolism, insulin sensitivity, and energy homeostasis. Reviews on the cardiometabolic aspects of PCOS are rare, and our knowledge from recent studies is expanding rapidly. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge, focusing on the alterations of cardiometabolic factors in women with PCOS. Further insight into this network of factors may facilitate finding therapeutic targets that should ameliorate not only ovarian dysfunction but also the various cardiometabolic alterations related to the syndrome.

Figure 1.

Cardiometabolic disturbances in PCOS. These include insulin resistance, hyperandrogenism, dyslipidemia, and alterations of the secretion and/or metabolic action of various adipokines, proinflammatory markers, and gut hormones, which may finally contribute to the observed increased prevalence of obesity, type 2 diabetes, NASH, OSA, and CVD in women with PCOS. However, for many of these factors, it remains to be determined whether they are causally involved in the pathogenesis of the syndrome or, alternatively, represent a consequence of changes in other factors.

Figure 2.

Relationship between BMI and insulin resistance in women with and without PCOS. Obesity and the PCOS status per se appear to be at least in part independent factors that contribute to the observed higher prevalence of insulin resistance and the metabolic syndrome in women with PCOS (33, 35); with increasing BMI, women with PCOS, compared with BMI-matched non-PCOS women, appear to accrue more metabolic abnormalities, likely contributing to the frequently observed higher insulin resistance in women with the syndrome. [Modified from N. Sattar: Polycystic ovary syndrome. The metabolic syndrome, 2nd ed. (edited by C. D. Byrne and S. H. Wild), Wiley-Blackwell, Oxford, UK, 2011 (171), with permission.]