 - Exclusion criteria will include the presence of any of the following: neoplasm, active thyroid disease i.e. not euthyroid, pregnancy or planned pregnancy, diabetes mellitus, Raynauds disease, anticoagulant therapy, or inability to provide informed consent. We will exclude participants who have started valproic acid derivatives in the preceding 6 months, given its association with insulin resistance and weight gain. Participants with active substance abuse or dependence will also be excluded. 