Low Hydroxychloroquine Intake, Blood Levels Linked to ASCVD Risk in Lupus

MONDAY, Sept. 28, 2026 (HealthDay News) — For patients with systemic lupus erythematosus (SLE), maintaining low long-term hydroxychloroquine (HCQ) intake and very low HCQ blood levels is associated with an increased risk for atherosclerotic cardiovascular disease (ASCVD), according to a study published online Aug. 3 in Arthritis Care & Research.

Shivani Garg, M.D., Ph.D., from Yale University in New Haven, Connecticut, and colleagues conducted a prospective longitudinal study involving 248 adults with SLE taking HCQ. The proportion of days covered (PDC) was used to estimate long-term HCQ intake, and whole-blood HCQ levels were a marker for recent exposure. Ten-year ASCVD risk was calculated, and associations between HCQ exposure patterns and ASCVD risk were assessed.

The researchers found that the risk for ASCVD was significantly higher at baseline (+2.1 percent) for patients with very low HCQ blood levels (<200 ng/mL) and low long-term intake (PDC <80 percent), with a mean predicted risk of 6.6 percent. The highest ASCVD risk at follow-up (5.7 percent) was seen for those who remained in or transitioned into these low-exposure categories over one year.

“This study underscores the need for targeted interventions that both improve long-term adherence to HCQ and help patients achieve the target HCQ blood levels,” Garg said in a statement. “It can be difficult for patients to commit to taking medication every single day for the rest of their lives. By giving patients clear data about their HCQ level and how it impacts their heart health and risk for flare-ups, we can help them make better-informed decisions about their medicines and care.”

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