The present study aims to investigate the effect of pioglitazone (30 mg/day) on endothelial function in premenopausal women with SLE (systemic lupus erythematosus). Patients with hypertension, endocrine, hepatic or renal diseases will not be included, or pregnant /breast feeding women. This is a randomized, double blind, placebo controlled study.

SLE (systemic lupus erythematosus) is characterized by accelerated atherosclerosis. The risk of suffering an acute myocardial infarction among premenopausal women with SLE is 50 times higher than control women of the same age. Insulin resistance and hyperinsulinemia are frequent in SLE. Lipid metabolism in SLE, as in other insulin resistant states, is characterized by high triglycerides, low HDL-cholesterol, normal LDL cholesterol (or slightly increased) and an increase in LDL's susceptibility to oxidation.

All these alterations can produce endothelial dysfunction which is present in SLE patients. Pioglitazone is a PPAR (peroxisome proliferator activated receptor) gamma agonist that can potentially improve insulin resistance, with a positive effect on the lipid profile (lowering of triglycerides, and a discrete increase in HDL-C) and improve endothelial function.

Patients will be randomized to receive either placebo or pioglitazone 30 mg/day during a period of 12 weeks. Endothelial function will be assessed by Positron Emission Tomography (PET).

Inclusion Criteria:

• Eligible participants were premenopausal women with SLE
• Older than 18 years
• Attending the outpatient Rheumatology Clinic at three Mexico City community tertiary care hospitals

Exclusion Criteria:

• menopause
• diabetes
• thyroid dysfunction
• neurological
• hepatic
• renal or liver disease
• personal history of high blood pressure
• CHD (coronary heart disease)
• cerebrovascular events
• chronic or acute infections
• malignancy
• nor history of chronic drugs or alcohol abuse
• smoking
• pregnancy or breast-feeding
• intake of hormones or lipid-regulating drugs