Antipsychotic drugs increase cardiovascular disease risk
MedWire News: The increase in cardiovascular risk associated with schizophrenia appears to be due to treatment with antipsychotic drugs, rather than the disease itself, a systematic review of studies into first treated episodes of psychosis reveals.
The mortality risk among schizophrenia patients rises to three times that of the general population 25 years after diagnosis, largely due to cardiovascular disease. As antipsychotic drugs are associated with increased cardiovascular risk, it is important to determine whether antipsychotic drugs reduce or increase overall mortality.
Debra Foley and Katherine Morley, from the University of Melbourne in Victoria, Australia, therefore searched the MEDLINE, PsycINFO, and Scopus databases for studies published between 1990 and 2010 on first-episode psychosis patients who were antipsychotic drug naïve or had only recently been exposed to antipsychotics. Twenty-five studies met the inclusion criteria, of which six included healthy controls.
Case-control studies indicated that there were few significant differences at baseline between patients and controls, and differences that were identified, such as higher waist-hip ratio and more intra-abdominal fat relative to body mass index (BMI) than controls, were either inconsistent or suffered from inadequate control matching.
For all antipsychotic drugs combined, there were significant changes in weight, BMI, and waist circumference that were evident after 1 month of treatment. At 6 weeks, there was a significant increase in interleukin-12 levels, and there were significant increases in subcutaneous and intra-abdominal fat, and leptin, total and low-density lipoprotein (LDL) cholesterol, triglycerides, and non-fasting glucose levels after 10 weeks.
By 6 months, there were significant changes in total, LDL and high-density lipoprotein cholesterol, triglycerides, fasting insulin and glucose, leptin, E-selectin, and adiponectin levels. Total body weight increased by 10-12% after 6-12 months, and weight gain continued for 3 or more years. The proportion of overweight or obese patients increased substantially over the first 6 months of treatment.
Interestingly, olanzapine was associated with significantly greater weight gain than risperidone or haloperidol over the first 6-8 weeks of treatment, and significantly more weight gain than haloperidol by 3-4 months. There were no significant differences in weight gain between treatments by 6 months.
The team concludes in the Archives of General Psychiatry: "Individuals treated with antipsychotics should be assessed before (or very soon after) first exposure to anti- psychotics to determine baseline cardiovascular risk.
"Regular monitoring is then recommended using consensus guidelines. Any clinically significant changes should be dealt with following recommended protocols and referral to a primary care physician or appropriate specialist."
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By Liam Davenport