Polycystic ovary syndrome (PCOS) is a common and complex reproductive and metabolic
condition with major health consequences across the lifespan. Insulin resistance is thought to
be a key underlying feature of PCOS, but its role in metabolic and reproductive
complications associated with the syndrome remains elusive. Therefore, the aim of the thesis
was to comprehensively assess the role of IR in PCOS. I report that IR is definitively intrinsic
to PCOS and exacerbated by BMI. But the effect of BMI on IR is more pronounced in PCOS
than controls. Diagnostic criteria and age seem to have little effect on IR in PCOS.
Furthermore, IR in PCOS seems to be negatively correlated with testosterone and positively
correlated with sex hormone binding globulin. Gonadotropins seem to have little effect on IR.
Various biomarkers associated with metabolic diseases appear more strongly associated with
obesity rather than with PCOS status and Plasminogen activator inhibitor-1 may also be a
novel independent biomarker with the ability to predict IR in women with and without PCOS.
This intrinsic IR in PCOS was not attributed to mitochondrial dysfunction and was not related
to the pathophysiology of reproductive dysfunction in PCOS as measured by Anti-Mullarian
hormone (AMH). However, AMH was able to detect PCOS status and may also be useful in
the diagnosis of PCOS. Collectively these chapters of related studies enhanced understanding
of IR in PCOS, including the relationship between intrinsic and extrinsic factors and IR and
provided information regarding potential markers to aid in diagnosing PCOS and IR.