Objective
To evaluate emotional processing in women with insulin-resistant polycystic ovary syndrome (IR-PCOS) and its relationship to glucose regulation and the mu-opioid system.
Design
Case-control pilot.
Setting
Tertiary referring medical center.
Patient(s)
Seven women with IR-PCOS and five non-insulin-resistant controls, aged 21–40 years, recruited from the general population.
Intervention(s)
Sixteen weeks of metformin (1,500 mg/day) in women with IR-PCOS.
Main Outcome Measure(s)
Assessment of mood, metabolic function, and neuronal activation during an emotional task using functional magnetic resonance imaging (fMRI), and mu-opioid receptor availability using positive emission tomography (PET).
Result(s)
We found that insulin-resistant PCOS patients [1] had greater limbic activation during an emotion task than controls (n = 5); [2] trended toward decreased positive affect and increased trait anxiety; [3] after metformin treatment, had limbic activation that no longer differed from controls; and [4] had positive correlations between fMRI limbic activation during emotional processing and mu-opioid binding potential.
Conclusion(s)
Patients with IR-PCOS had greater regional activation during an emotion task than the controls, although this resolved with metformin therapy. Alterations in mu-opioid neurotransmission may underlie limbic system activity and mood disorders in IR-PCOS.
Clinical Trial Registration Number
NCT00670800.