Hydroxychloroquine is a medicine that has been used for a long time to treat patients with malaria, rheumatoid arthritis, lupus and other conditions. It is closely related to chloroquine but with a better side effect profile for long term use. In treating these conditions it was discovered to have some beneficial properties like lowering cholesterol and lowering sugar in the blood of those who have diabetes. The mechanisms underlying these effects are unknown. In animal studies, we have discovered that chloroquine appears to decrease glucose, lower blood pressure and decrease atherosclerosis (hardening of the arteries). This collection of problems commonly occurs in the metabolic syndrome and diabetes mellitus, which affects over 20% and 7% of adults in Western countries respectively. We have recently looked at the effects of chloroquine on the metabolic syndrome in humans which showed that small doses given for a short period of time would reduce insulin resistance in patients with the metabolic syndrome. Several population studies have shown similar effects with hydroxychloroquine. Since hydroxychloroquine is similar to chloroquine, we thus expect similar effects on blood glucose, blood pressure and blood cholesterol in type 2 diabetes. This offers a unique opportunity to develop a novel approach for lowering blood pressure, lipids (cholesterol and triglycerides), and glucose in people at risk for heart disease