Hydroxychloroquine can improve most underlying coronary risk factors; however, there are a few studies on the effects of hydroxychloroquine on blood glucose and insulin resistance. The current study aimed to assess the effects of hydroxychloroquine on blood glucose control status as well as on level of lipid profile and inflammatory biomarkers in prediabetic patients.

In a randomized, double-blinded, controlled trial, 39 consecutive patients who were suffering from prediabetes and were referred to the Isfahan Endocrinology Center in January 2013 were randomly assigned to receive hydroxychloroquine (6.5 mg/kg/day) (n = 20) or placebo (n = 19) for 12 weeks. The biomarker indices and anthropometric parameters were tested before and after completion of treatment.

In both groups of patients receiving hydroxychloroquine and placebo, except for serum level of insulin that was significantly elevated after treatment by hydroxychloroquine, the changes in other parameters remained insignificant. Both groups experienced increase of insulin level, but this change was considerably higher in those groups receiving hydroxychloroquine. The group receiving hydroxychloroquine experienced reduction of glucose at 60 min of Oral Glucose Tolerance Test (OGTT) test after intervention, while the placebo group experienced increase of blood glucose at the same time.

The use of hydroxychloroquine may increase the serum insulin level in patients with prediabetic states who are at risk of developing diabetes mellitus.