Factors Associated with Plavix Response Identified

Obesity, diabetes, fibrinogen levels linked to reduced platelet inhibition

WEDNESDAY, Sept. 17 (HealthDay News) -- Obesity, diabetes mellitus and elevated plasma fibrinogen are associated with reduced platelet inhibition in patients with cardiovascular disease treated with clopidogrel (Plavix), according to the results of a study published in the Sept. 23 issue of the Journal of the American College of Cardiology.

Lawrence Ang, and colleagues from the University of California San Diego examined platelet function using a rapid bedside assay in 157 patients with cardiovascular disease treated with clopidogrel.

The researchers found that the mean platelet inhibition was 40.8 percent in response to clopidogrel. Lower platelet inhibition was found in patients with elevated plasma fibrinogen (375 mg/dL or greater), diabetes mellitus and elevated body mass index (25 kg/m2 or greater). Elevated fibrinogen was associated with diabetes, leading to reduced platelet inhibition in diabetic patients, while increased body mass index was independently associated with reduced platelet inhibition after clopidogrel treatment, the authors report.

"Based on the observations of Ang et al., adjustment of dosage by diabetic status and body mass index may be particularly useful in individualizing therapy," Deepak L. Bhatt, M.D., from Brigham and Women's Hospital in Boston, writes in an accompanying editorial. "Furthermore, it would be a major contribution if future research corroborates that fibrinogen truly is the link that makes diabetic platelets angry."

The author of the editorial reports a financial relationship with the pharmaceutical industry.

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