The risk for developing diabetes mellitus among patients with systemic lupus erythematosus declined significantly with increasing use of hydroxychloroquine in a retrospective cohort study of a national health insurance database in Taiwan.
This population-based cohort study is the first to demonstrate that hydroxychloroquine (HCQ) reduces the risk of diabetes in a dose-dependent manner in systemic lupus erythematosus (SLE) patients. In previous research, HCQ use has been shown to improve insulin sensitivity in SLE patients, and in rheumatoid arthritis patients, longer duration of HCQ treatment (> 4 years) has been shown before to have the greatest effect on lowering the incidence of diabetes, according to Dr. Der-Yuan Chen of Taichung (Taiwan) Veterans General Hospital and his associates.
Dr. Der-Yuan Chen
The investigators analyzed the first year of medication use in 8,628 patients with SLE in the National Health Insurance Research Database of Taiwan during 2001-2008, excluding those with less than 3 years of follow-up data and comorbid diagnoses of RA, psoriasis, or diabetes (Rheumatology [Oxford] 2015 Jan. 12 [doi:10.1093/rheumatology/keu451]).
The patients’ mean age was 37 years, and 88% were female. The patients who had used HCQ were significantly older (49 years vs. 37 years) and a greater proportion had taken glucocorticoids (92% vs. 73%). Those who had taken HCQ had significantly lower rates of hyperlipidemia, hypertension, stroke, and renal disease.
The effect of HCQ on diabetes risk became apparent in patients with an average daily glucocorticoid dose equivalent to 10 mg prednisolone or greater. That glucocorticoid dose was associated with increased diabetes risk (hazard ratio, 2.29; 95% confidence interval, 1.34-3.93), but a cumulative dose of 129 g HCQ or greater (equal to 200 mg/day for 1.8 years) reduced the risk of diabetes (HR, 0.26; 95% CI, 0.18-0.37), compared with those who did not take the drug. There was no significant relationship between HCQ use and incident diabetes for those who had a cumulative dose of less than 129 g (HR, 1.13; 95% CI, 0.81-1.59).
Patients who took both an average daily glucocorticoid dose equivalent to at least 10 mg prednisolone and a cumulative dose of less than 129 g HCQ had a higher diabetes risk than did those taking a smaller prednisolone dose, whereas those who took at least 129 g HCQ had a reduced risk of diabetes despite taking high-dose glucocorticoids.